Use DOTNET_STARTUP_HOOK to have the target run the tests (#91)

.editorconfig

@@ -1,40 +1,40 @@
-root=true
+root = true
 
 [*]
-charset=utf-8
-trim_trailing_whitespace=true
-insert_final_newline=true
-indent_style=space
-indent_size=4
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = space
+indent_size = 4
 
 # ReSharper properties
-resharper_xml_indent_size=2
-resharper_xml_max_line_length=100
-resharper_xml_tab_width=2
+resharper_xml_indent_size = 2
+resharper_xml_max_line_length = 100
+resharper_xml_tab_width = 2
 
 [*.{csproj,fsproj,sqlproj,targets,props,ts,tsx,css,json}]
-indent_style=space
-indent_size=2
+indent_style = space
+indent_size = 2
 
 [*.{fs,fsi}]
-fsharp_bar_before_discriminated_union_declaration=true
-fsharp_space_before_uppercase_invocation=true
-fsharp_space_before_class_constructor=true
-fsharp_space_before_member=true
-fsharp_space_before_colon=true
-fsharp_space_before_semicolon=true
-fsharp_multiline_bracket_style=aligned
-fsharp_newline_between_type_definition_and_members=true
-fsharp_align_function_signature_to_indentation=true
-fsharp_alternative_long_member_definitions=true
-fsharp_multi_line_lambda_closing_newline=true
-fsharp_experimental_keep_indent_in_branch=true
-fsharp_max_value_binding_width=80
-fsharp_max_record_width=0
-max_line_length=120
-end_of_line=lf
+fsharp_bar_before_discriminated_union_declaration = true
+fsharp_space_before_uppercase_invocation = true
+fsharp_space_before_class_constructor = true
+fsharp_space_before_member = true
+fsharp_space_before_colon = true
+fsharp_space_before_semicolon = true
+fsharp_multiline_bracket_style = aligned
+fsharp_newline_between_type_definition_and_members = true
+fsharp_align_function_signature_to_indentation = true
+fsharp_alternative_long_member_definitions = true
+fsharp_multi_line_lambda_closing_newline = true
+fsharp_experimental_keep_indent_in_branch = true
+fsharp_max_value_binding_width = 80
+fsharp_max_record_width = 0
+max_line_length = 120
+end_of_line = lf
 
 [*.{appxmanifest,build,dtd,nuspec,xaml,xamlx,xoml,xsd}]
-indent_style=space
-indent_size=2
-tab_width=2
+indent_style = space
+indent_size = 2
+tab_width = 2

.envrc

@@ -0,0 +1 @@
+use flake

.github/workflows/assert-contents.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+echo "Unzipping version from NuGet"
+ls from-nuget.nupkg
+mkdir from-nuget && cp from-nuget.nupkg from-nuget/zip.zip && cd from-nuget && unzip zip.zip && rm zip.zip && cd - || exit 1
+
+echo "Unzipping version from local build"
+ls packed/
+mkdir from-local && cp packed/*.nupkg from-local/zip.zip && cd from-local && unzip zip.zip && rm zip.zip && cd - || exit 1
+
+cd from-local && find . -type f -exec sha256sum {} \; | sort > ../from-local.txt && cd .. || exit 1
+cd from-nuget && find . -type f -and -not -name '.signature.p7s' -exec sha256sum {} \; | sort > ../from-nuget.txt && cd .. || exit 1
+
+diff from-local.txt from-nuget.txt

.github/workflows/dotnet.yaml

@@ -38,7 +38,7 @@ jobs:
     - name: Build
       run: 'nix develop --command dotnet build --no-restore --configuration ${{matrix.config}}'
     - name: Test
-      run: 'nix develop --command dotnet test --no-build --verbosity normal --configuration ${{matrix.config}}'
+      run: 'nix develop --command dotnet test --no-build --verbosity normal --configuration ${{matrix.config}} --framework net8.0'
 
   selftest:
     runs-on: ubuntu-latest
@@ -71,7 +71,49 @@ jobs:
     - name: Build
       run: 'nix develop --command dotnet build --no-restore --configuration Release'
     - name: Test using self
-      run: 'nix develop --command dotnet exec ./WoofWare.NUnitTestRunner/bin/Release/net8.0/WoofWare.NUnitTestRunner.dll ./Consumer/bin/Release/net8.0/Consumer.dll --trx TrxOut/out.trx'
+      run: 'nix develop --command dotnet exec ./WoofWare.NUnitTestRunner/bin/Release/net6.0/WoofWare.NUnitTestRunner.dll ./Consumer/bin/Release/net8.0/Consumer.dll --trx TrxOut/out.trx'
+    - name: Parse Trx files
+      uses: NasAmin/trx-parser@v0.6.0
+      if: always()
+      id: trx-parser
+      with:
+        TRX_PATH: ${{ github.workspace }}/TrxOut
+        REPO_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  selftest-net6:
+    runs-on: ubuntu-latest
+    permissions:
+      actions: none
+      checks: write
+      contents: read
+      deployments: none
+      id-token: none
+      issues: none
+      discussions: none
+      packages: none
+      pages: none
+      pull-requests: read
+      repository-projects: none
+      security-events: none
+      statuses: read
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0 # so that NerdBank.GitVersioning has access to history
+    - name: Install Nix
+      uses: cachix/install-nix-action@V27
+      with:
+        extra_nix_config: |
+          access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+    - name: Restore dependencies
+      run: nix develop --command dotnet restore
+    - name: Build runner
+      run: 'nix develop --command dotnet build WoofWare.NUnitTestRunner --configuration Release'
+    - name: Build target
+      run: 'nix develop --command dotnet build Consumer --configuration Release'
+    - name: Test using self
+      run: 'nix develop .#net6 --command ./WoofWare.NUnitTestRunner/bin/Release/net6.0/WoofWare.NUnitTestRunner ./Consumer/bin/Release/net6.0/Consumer.dll --trx TrxOut/out.trx'
     - name: Parse Trx files
       uses: NasAmin/trx-parser@v0.6.0
       if: always()
@@ -240,11 +282,53 @@ jobs:
     steps:
       - run: echo "All required checks complete."
 
-  nuget-publish:
+  attestation-lib:
+    runs-on: ubuntu-latest
+    needs: [all-required-checks-complete]
+    if: ${{ !github.event.repository.fork && github.ref == 'refs/heads/main' }}
+    permissions:
+      id-token: write
+      attestations: write
+      contents: read
+    steps:
+      - name: Download NuGet artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: nuget-package-lib
+          path: packed
+      - name: Attest Build Provenance
+        uses: actions/attest-build-provenance@897ed5eab6ed058a474202017ada7f40bfa52940 # v1.0.0
+        with:
+          subject-path: "packed/*.nupkg"
+
+  attestation-tool:
+    runs-on: ubuntu-latest
+    needs: [all-required-checks-complete]
+    if: ${{ !github.event.repository.fork && github.ref == 'refs/heads/main' }}
+    permissions:
+      id-token: write
+      attestations: write
+      contents: read
+    steps:
+      - name: Download NuGet artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: nuget-package-tool
+          path: packed
+      - name: Attest Build Provenance
+        uses: actions/attest-build-provenance@897ed5eab6ed058a474202017ada7f40bfa52940 # v1.0.0
+        with:
+          subject-path: "packed/*.nupkg"
+
+  nuget-publish-lib:
     runs-on: ubuntu-latest
     if: ${{ !github.event.repository.fork && github.ref == 'refs/heads/main' }}
     needs: [all-required-checks-complete]
     environment: main-deploy
+    permissions:
+      id-token: write
+      attestations: write
+      contents: read
     steps:
       - uses: actions/checkout@v4
       - name: Install Nix
@@ -252,20 +336,73 @@ jobs:
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-      - name: Download NuGet artifact (lib)
+      - name: Download NuGet artifact
         uses: actions/download-artifact@v4
         with:
           name: nuget-package-lib
-          path: packed-lib
-      - name: Publish to NuGet (lib)
-        run: nix develop --command dotnet nuget push "packed-lib/WoofWare.NUnitTestRunner.Lib.*.nupkg" --api-key ${{ secrets.NUGET_API_KEY }} --source https://api.nuget.org/v3/index.json --skip-duplicate
-      - name: Download NuGet artifact (tool)
+          path: packed
+      - name: Publish to NuGet
+        id: publish-success
+        env:
+          NUGET_API_KEY: ${{ secrets.NUGET_API_KEY }}
+        run: 'nix develop --command bash ./.github/workflows/nuget-push.sh "packed/WoofWare.NUnitTestRunner.Lib.*.nupkg"'
+      - name: Wait for availability
+        if: steps.publish-success.outputs.result == 'published'
+        env:
+          PACKAGE_VERSION: ${{ steps.publish-success.outputs.version }}
+        run: 'echo "$PACKAGE_VERSION" && while ! curl -L --fail -o from-nuget.nupkg "https://www.nuget.org/api/v2/package/WoofWare.NUnitTestRunner.Lib/$PACKAGE_VERSION" ; do sleep 10; done'
+      # Astonishingly, NuGet.org considers it to be "more secure" to tamper with my package after upload (https://devblogs.microsoft.com/nuget/introducing-repository-signatures/).
+      # So we have to *re-attest* it after it's uploaded. Mind-blowing.
+      - name: Assert package contents
+        if: steps.publish-success.outputs.result == 'published'
+        run: 'bash ./.github/workflows/assert-contents.sh'
+      - name: Attest Build Provenance
+        if: steps.publish-success.outputs.result == 'published'
+        uses: actions/attest-build-provenance@897ed5eab6ed058a474202017ada7f40bfa52940 # v1.0.0
+        with:
+          subject-path: "from-nuget.nupkg"
+
+  nuget-publish-tool:
+    runs-on: ubuntu-latest
+    if: ${{ !github.event.repository.fork && github.ref == 'refs/heads/main' }}
+    needs: [all-required-checks-complete]
+    environment: main-deploy
+    permissions:
+      id-token: write
+      attestations: write
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Nix
+        uses: cachix/install-nix-action@V27
+        with:
+          extra_nix_config: |
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+      - name: Download NuGet artifact
         uses: actions/download-artifact@v4
         with:
           name: nuget-package-tool
-          path: packed-tool
-      - name: Publish to NuGet (tool)
-        run: nix develop --command dotnet nuget push "packed-tool/WoofWare.NUnitTestRunner.*.nupkg" --api-key ${{ secrets.NUGET_API_KEY }} --source https://api.nuget.org/v3/index.json --skip-duplicate
+          path: packed
+      - name: Publish to NuGet
+        id: publish-success
+        env:
+          NUGET_API_KEY: ${{ secrets.NUGET_API_KEY }}
+        run: 'nix develop --command bash ./.github/workflows/nuget-push.sh "packed/WoofWare.NUnitTestRunner.*.nupkg"'
+      - name: Wait for availability
+        if: steps.publish-success.outputs.result == 'published'
+        env:
+          PACKAGE_VERSION: ${{ steps.publish-success.outputs.version }}
+        run: 'echo "$PACKAGE_VERSION" && while ! curl -L --fail -o from-nuget.nupkg "https://www.nuget.org/api/v2/package/WoofWare.NUnitTestRunner/$PACKAGE_VERSION" ; do sleep 10; done'
+      # Astonishingly, NuGet.org considers it to be "more secure" to tamper with my package after upload (https://devblogs.microsoft.com/nuget/introducing-repository-signatures/).
+      # So we have to *re-attest* it after it's uploaded. Mind-blowing.
+      - name: Assert package contents
+        if: steps.publish-success.outputs.result == 'published'
+        run: 'bash ./.github/workflows/assert-contents.sh'
+      - name: Attest Build Provenance
+        if: steps.publish-success.outputs.result == 'published'
+        uses: actions/attest-build-provenance@897ed5eab6ed058a474202017ada7f40bfa52940 # v1.0.0
+        with:
+          subject-path: "from-nuget.nupkg"
 
   github-release-tool:
     runs-on: ubuntu-latest

.github/workflows/nuget-push.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+SOURCE_NUPKG=$(find . -type f -name '*.nupkg')
+
+PACKAGE_VERSION=$(basename "$SOURCE_NUPKG" | rev | cut -d '.' -f 2-4 | rev)
+
+echo "version=$PACKAGE_VERSION" >> "$GITHUB_OUTPUT"
+
+tmp=$(mktemp)
+
+if ! dotnet nuget push "$SOURCE_NUPKG" --api-key "$NUGET_API_KEY" --source https://api.nuget.org/v3/index.json > "$tmp" ; then
+    cat "$tmp"
+    if grep 'already exists and cannot be modified' "$tmp" ; then
+        echo "result=skipped" >> "$GITHUB_OUTPUT"
+        exit 0
+    else
+        echo "Unexpected failure to upload"
+        exit 1
+    fi
+fi
+
+cat "$tmp"
+
+echo "result=published" >> "$GITHUB_OUTPUT"

Consumer/Consumer.fsproj

@@ -1,8 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net8.0</TargetFramework>
-
+        <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
         <IsPackable>false</IsPackable>
         <IsTestProject>true</IsTestProject>
     </PropertyGroup>
@@ -10,6 +9,8 @@
     <ItemGroup>
         <Compile Include="NoAttribute.fs" />
         <Compile Include="Inconclusive.fs" />
+        <Compile Include="RunSubProcess.fs" />
+        <Compile Include="TestNonParallel.fs" />
         <Compile Include="TestParallel.fs" />
         <Compile Include="TestStdout.fs" />
         <Compile Include="TestParameterisedFixture.fs" />
@@ -25,9 +26,9 @@
 
     <ItemGroup>
       <PackageReference Include="FsUnit" Version="6.0.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0"/>
-        <PackageReference Include="NUnit" Version="4.1.0"/>
-        <PackageReference Include="NUnit3TestAdapter" Version="4.5.0"/>
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0"/>
+      <PackageReference Include="NUnit" Version="4.1.0"/>
+      <PackageReference Include="NUnit3TestAdapter" Version="4.5.0"/>
     </ItemGroup>
 
 </Project>

Consumer/RunSubProcess.fs

@@ -0,0 +1,45 @@
+namespace Consumer
+
+open System
+open System.Diagnostics
+open System.IO
+open System.IO.Compression
+open System.Text
+open NUnit.Framework
+open FsUnitTyped
+
+[<TestFixture>]
+module RunSubProcess =
+    [<Test>]
+    let ``Run a subprocess`` () =
+        let exe = "/bin/bash"
+        let args = [ "-c" ; "echo hi >&2 && echo bye" ]
+        let workingDir = None
+
+        let psi =
+            ProcessStartInfo (
+                exe,
+                UseShellExecute = false,
+                RedirectStandardError = true,
+                RedirectStandardOutput = true,
+                WorkingDirectory = Option.toObj workingDir
+            )
+
+        for arg in args do
+            psi.ArgumentList.Add arg
+
+        psi.EnvironmentVariables.Add ("THING", Path.Combine (AppDomain.CurrentDomain.BaseDirectory, "hi"))
+        let stderr = StringBuilder ()
+        use proc = new Process (StartInfo = psi)
+        proc.OutputDataReceived.Add (fun e -> printfn $"%s{e.Data}")
+
+        proc.ErrorDataReceived.Add (fun e ->
+            eprintfn $"%s{e.Data}"
+            stderr.AppendLine e.Data |> ignore
+        )
+
+        proc.Start () |> shouldEqual true
+        proc.BeginOutputReadLine ()
+        proc.BeginErrorReadLine ()
+
+        proc.WaitForExit ()

Consumer/TestNonParallel.fs

@@ -0,0 +1,19 @@
+namespace Consumer
+
+open System
+open System.Threading
+open NUnit.Framework
+open FsUnitTyped
+
+[<TestFixture>]
+[<NonParallelizable>]
+module TestNonParallel =
+    let defaults = List.init 40 id
+    let lock = ref 0
+
+    [<TestCaseSource(nameof defaults)>]
+    let ``Default thing, but not parallel`` (i : int) =
+        Interlocked.Increment lock |> shouldEqual 1
+        Thread.Sleep (TimeSpan.FromMilliseconds (float i))
+        lock.Value <- 0
+        i |> shouldEqual i

Consumer/TestParallel.fs

@@ -1,5 +1,7 @@
 namespace Consumer
 
+open System
+open System.Threading
 open NUnit.Framework
 open FsUnitTyped
 
@@ -7,53 +9,58 @@ open FsUnitTyped
 [<Parallelizable>]
 module TestParallelDefault =
 
-    let defaults = List.init 100 id
+    let defaults = List.init 60 id
 
     [<TestCaseSource(nameof defaults)>]
-    let ``Default thing`` (i : int) =
-        System.Console.WriteLine i
+    let ``Default thing, no scope`` (i : int) =
+        Console.WriteLine i
+        Thread.Sleep (TimeSpan.FromMilliseconds (float i))
         i |> shouldEqual i
 
 [<TestFixture>]
 [<Parallelizable(ParallelScope.All)>]
 module TestParallelAllScope =
 
-    let defaults = List.init 100 id
+    let defaults = List.init 60 id
 
     [<TestCaseSource(nameof defaults)>]
-    let ``Default thing`` (i : int) =
-        System.Console.WriteLine i
+    let ``Thing, all scope`` (i : int) =
+        Console.WriteLine i
+        Thread.Sleep (TimeSpan.FromMilliseconds (float i))
         i |> shouldEqual i
 
 [<TestFixture>]
 [<Parallelizable(ParallelScope.Self)>]
 module TestParallelSelfScope =
 
-    let defaults = List.init 100 id
+    let defaults = List.init 60 id
 
     [<TestCaseSource(nameof defaults)>]
-    let ``Default thing`` (i : int) =
-        System.Console.WriteLine i
+    let ``Thing, self scope`` (i : int) =
+        Console.WriteLine i
+        Thread.Sleep (TimeSpan.FromMilliseconds (float i))
         i |> shouldEqual i
 
 [<TestFixture>]
 [<Parallelizable(ParallelScope.Children)>]
 module TestParallelChildrenScope =
 
-    let defaults = List.init 100 id
+    let defaults = List.init 60 id
 
     [<TestCaseSource(nameof defaults)>]
-    let ``Default thing`` (i : int) =
-        System.Console.WriteLine i
+    let ``Thing, children scope`` (i : int) =
+        Console.WriteLine i
+        Thread.Sleep (TimeSpan.FromMilliseconds (float i))
         i |> shouldEqual i
 
 [<TestFixture>]
 [<Parallelizable(ParallelScope.Fixtures)>]
 module TestParallelFixturesScope =
 
-    let defaults = List.init 100 id
+    let defaults = List.init 60 id
 
     [<TestCaseSource(nameof defaults)>]
-    let ``Default thing`` (i : int) =
-        System.Console.WriteLine i
+    let ``Thing, fixtures scope`` (i : int) =
+        Console.WriteLine i
+        Thread.Sleep (TimeSpan.FromMilliseconds (float i))
         i |> shouldEqual i

Consumer/TestSetUp.fs

@@ -47,10 +47,11 @@ module TestSetUp =
 
         setUpTimesSeen
         |> Seq.toList
+        |> List.sort
         // Six tests: one for Test, two for the TestCase, three for the Repeat.
         |> shouldEqual [ 1..6 ]
 
-        tearDownTimesSeen |> Seq.toList |> shouldEqual [ 1..6 ]
+        tearDownTimesSeen |> Seq.toList |> List.sort |> shouldEqual [ 1..6 ]
 
     [<Test>]
     let ``Test 1`` () =

Consumer/TestValues.fs

@@ -86,14 +86,42 @@ module TestValues =
 
     [<OneTimeTearDown>]
     let ``Values are all OK`` () =
-        seen1 |> Seq.toList |> shouldEqual [ true ; false ]
-        seen2 |> Seq.toList |> shouldEqual [ (true, false) ; (false, true) ]
-        seen3 |> Seq.toList |> shouldEqual [ (88, box 29) ; (31, box 0) ]
-        seen4 |> Seq.toList |> shouldEqual [ ("hi", box "ohh") ; ("bye", null) ]
-        seen5 |> Seq.toList |> shouldEqual [ (88, box 29) ; (31, box 29) ]
-        seen6 |> Seq.toList |> shouldEqual [ ("hi", box "ohh") ; ("bye", box "ohh") ]
-        seen7 |> Seq.toList |> shouldEqual [ (88, box 29) ; (31, box 29) ]
-        seen8 |> Seq.toList |> shouldEqual [ ("hi", box "ohh") ; ("bye", box "ohh") ]
+        seen1 |> Seq.toList |> List.sort |> shouldEqual [ false ; true ]
+
+        seen2
+        |> Seq.toList
+        |> List.sort
+        |> shouldEqual [ (false, true) ; (true, false) ]
+
+        seen3
+        |> Seq.toList
+        |> List.sortBy fst
+        |> shouldEqual [ (31, box 0) ; (88, box 29) ]
+
+        seen4
+        |> Seq.toList
+        |> List.sortBy fst
+        |> shouldEqual [ ("bye", null) ; ("hi", box "ohh") ]
+
+        seen5
+        |> Seq.toList
+        |> List.sortBy fst
+        |> shouldEqual [ (31, box 29) ; (88, box 29) ]
+
+        seen6
+        |> Seq.toList
+        |> List.sortBy fst
+        |> shouldEqual [ ("bye", box "ohh") ; ("hi", box "ohh") ]
+
+        seen7
+        |> Seq.toList
+        |> List.sortBy fst
+        |> shouldEqual [ (31, box 29) ; (88, box 29) ]
+
+        seen8
+        |> Seq.toList
+        |> List.sortBy fst
+        |> shouldEqual [ ("bye", box "ohh") ; ("hi", box "ohh") ]
 
         seen9
         |> Seq.toList

WoofWare.NUnitTestRunner.Lib/Args.fs

@@ -0,0 +1,99 @@
+namespace WoofWare.NUnitTestRunner
+
+open System
+open System.IO
+
+[<AutoOpen>]
+module internal Patterns =
+    let (|Key|_|) (start : string) (s : string) : string option =
+        if s.StartsWith (start + "=", StringComparison.Ordinal) then
+            s.Substring (start.Length + 1) |> Some
+        else
+            None
+
+/// Represents how verbose the test runner's logging should be.
+[<RequireQualifiedAccess>]
+type LogLevel =
+    /// Don't log any information about the test run.
+    | Nothing
+    /// Log as much information as is available about the test run.
+    | Verbose
+
+/// Arguments controlling the test runner itself (not the tests therein).
+type Args =
+    {
+        /// The DLL containing the tests we'll reflectively discover and invoke.
+        Dll : FileInfo
+        /// If set, the output file into which we will write a TRX report. (We'll create parent directories as necessary.)
+        Trx : FileInfo option
+        /// Also contains the original string which specified the filter.
+        Filter : (string * Filter) option
+        /// How verbose to be with the test runner's own logging.
+        Logging : LogLevel
+        /// Maximum number of tests which can run concurrently. This setting overrides any LevelOfParallelism reflectively
+        /// extracted from the assembly under test.
+        LevelOfParallelism : int option
+        /// Abort if the test runner is running for longer than this timeout.
+        Timeout : TimeSpan option
+    }
+
+    /// Parse `argv` into a structured Args.
+    static member Parse (args : string list) : Args =
+        match args with
+        | [] -> failwith "The first arg must be a positional arg, the DLL to test."
+        | dll :: args ->
+
+        let rec go
+            (trx : FileInfo option)
+            (filter : (string * Filter) option)
+            (logging : LogLevel option)
+            (par : int option)
+            (timeout : TimeSpan option)
+            (args : string list)
+            =
+            match args with
+            | [] ->
+                {
+                    Dll = FileInfo dll
+                    Trx = trx
+                    Filter = filter
+                    Logging = logging |> Option.defaultValue LogLevel.Nothing
+                    LevelOfParallelism = par
+                    Timeout = timeout
+                }
+            | Key "--filter" filterStr :: rest
+            | "--filter" :: filterStr :: rest ->
+                match filter with
+                | Some _ -> failwith "Two conflicting filters; you can only specify --filter once"
+                | None -> go trx (Some (filterStr, Filter.parse filterStr)) logging par timeout rest
+            | Key "--trx" trxStr :: rest
+            | "--trx" :: trxStr :: rest ->
+                match trx with
+                | Some _ -> failwith "Two conflicting TRX outputs; you can only specify --trx once"
+                | None -> go (Some (FileInfo trxStr)) filter logging par timeout rest
+            | Key "--verbose" verboseStr :: rest
+            | "--verbose" :: verboseStr :: rest ->
+                match logging with
+                | Some _ -> failwith "Two conflicting --verbose outputs; you can only specify --verbose once"
+                | None ->
+                    let verbose =
+                        if Boolean.Parse verboseStr then
+                            LogLevel.Verbose
+                        else
+                            LogLevel.Nothing
+
+                    go trx filter (Some verbose) par timeout rest
+            | Key "--parallelism" parStr :: rest
+            | "--parallelism" :: parStr :: rest ->
+                match par with
+                | Some _ -> failwith "Two conflicting --parallelism outputs; you can only specify --parallelism once"
+                | None -> go trx filter logging (Some (Int32.Parse parStr)) timeout rest
+            | Key "--timeout-seconds" timeoutStr :: rest
+            | "--timeout-seconds" :: timeoutStr :: rest ->
+                match timeout with
+                | Some _ ->
+                    failwith "Two conflicting --timeout-seconds outputs; you can only specify --timeout-seconds once"
+                | None -> go trx filter logging par (Some (TimeSpan.FromSeconds (Int32.Parse timeoutStr |> float))) rest
+            | k :: _rest -> failwith $"Unrecognised arg %s{k}"
+
+        go None None None None None args

WoofWare.NUnitTestRunner.Lib/AssemblyLevelAttributes.fs

@@ -0,0 +1,58 @@
+namespace WoofWare.NUnitTestRunner
+
+open System.Reflection
+
+/// Attributes at the assembly level which control the behaviour of NUnit.
+type AssemblyLevelAttributes =
+    {
+        /// How many tests can be running at once, if anything's running in parallel.
+        Parallelism : int option
+        /// Whether the tests in this assembly can be parallelised at all.
+        Parallelizable : Parallelizable<AssemblyParallelScope> option
+    }
+
+[<RequireQualifiedAccess>]
+module AssemblyLevelAttributes =
+
+    /// Reflectively obtain the values of any relevant assembly attributes.
+    let get (assy : Assembly) : AssemblyLevelAttributes =
+        ((None, None), assy.CustomAttributes)
+        ||> Seq.fold (fun (levelPar, par) attr ->
+            match attr.AttributeType.FullName with
+            | "NUnit.Framework.LevelOfParallelismAttribute" ->
+                let arg = attr.ConstructorArguments |> Seq.exactlyOne |> _.Value |> unbox<int>
+
+                match levelPar with
+                | None -> (Some arg, par)
+                | Some existing ->
+                    failwith $"Assembly %s{assy.Location} declares parallelism %i{arg} and also %i{existing}"
+            | "NUnit.Framework.NonParallelizableAttribute" ->
+                match levelPar with
+                | None -> (Some 1, par)
+                | Some existing ->
+                    failwith
+                        $"Assembly %s{assy.Location} declares non-parallelizable and also parallelism %i{existing}"
+            | "NUnit.Framework.ParallelizableAttribute" ->
+                match par with
+                | Some _ -> failwith "Got multiple Parallelize attributes in assembly"
+                | None ->
+                    match attr.ConstructorArguments |> Seq.toList with
+                    | [] -> levelPar, Some (Parallelizable.Yes AssemblyParallelScope.Fixtures)
+                    | [ v ] ->
+                        match v.Value with
+                        | :? int as v ->
+                            match v with
+                            | 512 -> levelPar, Some (Parallelizable.Yes AssemblyParallelScope.Fixtures)
+                            | 256 -> levelPar, Some (Parallelizable.Yes AssemblyParallelScope.Children)
+                            | 257 -> failwith "ParallelScope.All is invalid on assemblies; only Fixtures or Children"
+                            | 1 -> failwith "ParallelScope.Self is invalid on assemblies; only Fixtures or Children"
+                            | v -> failwith $"Could not recognise value %i{v} of parallel scope on assembly"
+                        | v -> failwith $"Unexpectedly non-int value %O{v} of parallel scope on assembly"
+                    | _ -> failwith "unexpectedly got multiple args to Parallelizable on assembly"
+            | _ -> levelPar, par
+        )
+        |> fun (par, canPar) ->
+            {
+                Parallelizable = canPar
+                Parallelism = par
+            }

WoofWare.NUnitTestRunner.Lib/Context.fs

@@ -89,8 +89,13 @@ type TestContexts =
             AsyncLocal = local
         }
 
-    member internal this.Stdout : TextWriter = this.StdOutWriter
-    member internal this.Stderr : TextWriter = this.StdErrWriter
+    /// An output stream which will identify the ExecutionContext it's being written to from,
+    /// and will separate that output into its own stream internally.
+    member this.Stdout : TextWriter = this.StdOutWriter
+
+    /// An output stream which will identify the ExecutionContext it's being written to from,
+    /// and will separate that output into its own stream internally.
+    member this.Stderr : TextWriter = this.StdErrWriter
 
     member internal this.DumpStdout (id : OutputStreamId) : string =
         lock

WoofWare.NUnitTestRunner.Lib/CreateTrxReport.fs

@@ -0,0 +1,243 @@
+namespace WoofWare.NUnitTestRunner
+
+open System
+open System.Reflection
+
+/// Methods for constructing TRX reports.
+[<RequireQualifiedAccess>]
+module BuildTrxReport =
+
+    /// Build a TRX report from the given results.
+    let build
+        (assy : Assembly)
+        (creationTime : DateTimeOffset)
+        (startTime : DateTimeOffset)
+        (results : FixtureRunResults list)
+        : TrxReport
+        =
+        let finishTime = DateTimeOffset.Now
+        let finishTimeHumanReadable = finishTime.ToString @"yyyy-MM-dd HH:mm:ss"
+        let nowMachine = finishTime.ToString @"yyyy-MM-dd_HH_mm_ss"
+
+        let testListId = Guid.NewGuid ()
+
+        let testDefinitions, testEntries =
+            results
+            |> List.collect (fun results -> results.IndividualTestRunMetadata)
+            |> List.map (fun (data, _) ->
+                let defn =
+                    {
+                        Name = data.TestName
+                        Storage = assy.Location.ToLowerInvariant ()
+                        Id = data.TestId
+                        Execution =
+                            {
+                                Id = data.ExecutionId
+                            }
+                        TestMethod =
+                            {
+                                CodeBase = assy.Location
+                                AdapterTypeName = Uri "executor://woofware/"
+                                ClassName = data.ClassName
+                                Name = data.TestName
+                            }
+                    }
+
+                let entry : TrxTestEntry =
+                    {
+                        TestListId = testListId
+                        ExecutionId = data.ExecutionId
+                        TestId = data.TestId
+
+                    }
+
+                defn, entry
+            )
+            |> List.unzip
+
+        let hostname = Environment.MachineName
+
+        let settings =
+            {
+                Name = "default"
+                Id = Guid.NewGuid ()
+                Deployment =
+                    {
+                        RunDeploymentRoot = $"_%s{hostname}_%s{nowMachine}"
+                    }
+            }
+
+        let testList : TrxTestListEntry =
+            {
+                Id = testListId
+                Name = "All"
+            }
+
+        let counters =
+            (TrxCounters.Zero, results)
+            // TODO: this is woefully inefficient
+            ||> List.fold (fun counters results ->
+                let counters =
+                    (counters, results.Failed)
+                    ||> List.fold (fun counters (_, _) ->
+                        // TODO: the counters can be more specific about the failure mode
+                        counters.AddFailed ()
+                    )
+
+                let counters =
+                    (counters, results.OtherFailures)
+                    ||> List.fold (fun counters _ ->
+                        // TODO: the counters can be more specific about the failure mode
+                        counters.AddFailed ()
+                    )
+
+                (counters, results.Success)
+                ||> List.fold (fun counters (_, success, _) ->
+                    match success with
+                    | TestMemberSuccess.Ok -> counters.AddPassed ()
+                    | TestMemberSuccess.Ignored _
+                    | TestMemberSuccess.Explicit _ -> counters.AddNotExecuted ()
+                    | TestMemberSuccess.Inconclusive _ -> counters.AddInconclusive ()
+                )
+            )
+
+        // TODO: I'm sure we can do better than this; there's a whole range of possible
+        // states!
+        let outcome =
+            if counters.Failed > 0u then
+                TrxOutcome.Failed
+            else
+                TrxOutcome.Completed
+
+        let resultSummary : TrxResultsSummary =
+            {
+                Outcome = outcome
+                Counters = counters
+                Output =
+                    {
+                        StdOut = None
+                        StdErr = None
+                        ErrorInfo = None
+                    }
+                RunInfos =
+                    [
+                    // TODO: capture stdout
+                    ]
+            }
+
+        let times : TrxReportTimes =
+            {
+                Creation = creationTime
+                Queuing = startTime
+                Start = startTime
+                Finish = finishTime
+
+            }
+
+        let magicGuid = Guid.Parse "13cdc9d9-ddb5-4fa4-a97d-d965ccfc6d4b"
+
+        let results =
+            results
+            |> List.collect (fun results -> results.IndividualTestRunMetadata)
+            |> List.map (fun (i, cause) ->
+                let exc =
+                    match cause with
+                    | Choice2Of3 _ -> None
+                    | Choice1Of3 (TestMemberFailure.Malformed reasons) ->
+                        {
+                            StackTrace = None
+                            Message = reasons |> String.concat "\n" |> Some
+                        }
+                        |> Some
+                    | Choice1Of3 (TestMemberFailure.Failed fail)
+                    | Choice1Of3 (TestMemberFailure.Failed fail)
+                    | Choice1Of3 (TestMemberFailure.Failed fail) ->
+                        ((None, None), fail)
+                        ||> List.fold (fun (stackTrace, message) tf ->
+                            match tf with
+                            | TestFailure.TestFailed (UserMethodFailure.Threw (_, exc))
+                            | TestFailure.SetUpFailed (UserMethodFailure.Threw (_, exc))
+                            | TestFailure.TearDownFailed (UserMethodFailure.Threw (_, exc)) ->
+                                let stackTrace =
+                                    match stackTrace with
+                                    | None -> (exc : Exception).ToString ()
+                                    | Some s -> s
+
+                                (Some stackTrace, message)
+                            | TestFailure.TestFailed (UserMethodFailure.ReturnedNonUnit (_, ret))
+                            | TestFailure.SetUpFailed (UserMethodFailure.ReturnedNonUnit (_, ret))
+                            | TestFailure.TearDownFailed (UserMethodFailure.ReturnedNonUnit (_, ret)) ->
+                                let newMessage = $"returned non-unit value %O{ret}"
+
+                                let message =
+                                    match message with
+                                    | None -> newMessage
+                                    | Some message -> $"%s{message}\n%s{newMessage}"
+
+                                (stackTrace, Some message)
+                        )
+                        |> fun (stackTrace, message) ->
+                            {
+                                StackTrace = stackTrace
+                                Message = message
+                            }
+                            |> Some
+                    | Choice3Of3 (UserMethodFailure.Threw (_, exc)) ->
+                        {
+                            StackTrace = (exc : Exception).ToString () |> Some
+                            Message = None
+                        }
+                        |> Some
+                    | Choice3Of3 (UserMethodFailure.ReturnedNonUnit (_, ret)) ->
+                        {
+                            Message = $"returned non-unit value %O{ret}" |> Some
+                            StackTrace = None
+                        }
+                        |> Some
+
+                let outcome =
+                    match cause with
+                    | Choice1Of3 _ -> TrxTestOutcome.Failed
+                    | Choice2Of3 TestMemberSuccess.Ok -> TrxTestOutcome.Passed
+                    | Choice2Of3 (TestMemberSuccess.Inconclusive _) -> TrxTestOutcome.Inconclusive
+                    | Choice2Of3 (TestMemberSuccess.Ignored _)
+                    | Choice2Of3 (TestMemberSuccess.Explicit _) -> TrxTestOutcome.NotExecuted
+                    // TODO: we can totally do better here, more fine-grained classification
+                    | Choice3Of3 _ -> TrxTestOutcome.Failed
+
+                {
+                    ExecutionId = i.ExecutionId
+                    TestId = i.TestId
+                    TestName = i.TestName
+                    ComputerName = i.ComputerName
+                    Duration = i.End - i.Start
+                    StartTime = i.Start
+                    EndTime = i.End
+                    TestType = magicGuid
+                    Outcome = outcome
+                    TestListId = testListId
+                    RelativeResultsDirectory = i.ExecutionId.ToString () // for some reason
+                    Output =
+                        match i.StdOut, i.StdErr, exc with
+                        | None, None, None -> None
+                        | stdout, stderr, exc ->
+                            Some
+                                {
+                                    TrxOutput.StdOut = stdout
+                                    StdErr = stderr
+                                    ErrorInfo = exc
+                                }
+                }
+            )
+
+        {
+            Id = Guid.NewGuid ()
+            Name = $"@%s{hostname} %s{finishTimeHumanReadable}"
+            Times = times
+            Settings = settings
+            Results = results
+            TestDefinitions = testDefinitions
+            TestEntries = testEntries
+            TestLists = [ testList ]
+            ResultsSummary = resultSummary
+        }

WoofWare.NUnitTestRunner.Lib/Domain.fs

@@ -88,6 +88,7 @@ type SingleTestMethod =
 
 /// A test fixture (usually represented by the [<TestFixture>]` attribute), which may contain many tests,
 /// each of which may run many times.
+[<NoComparison>]
 type TestFixture =
     {
         /// The assembly which contains this TestFixture, loaded into a separate context.

WoofWare.NUnitTestRunner.Lib/DotnetRuntime.fs

@@ -7,11 +7,7 @@ open WoofWare.DotnetRuntimeLocator
 /// Functions for locating .NET runtimes.
 [<RequireQualifiedAccess>]
 module DotnetRuntime =
-    let private selectRuntime
-        (config : RuntimeOptions)
-        (f : DotnetEnvironmentInfo)
-        : Choice<DotnetEnvironmentFrameworkInfo, DotnetEnvironmentSdkInfo> option
-        =
+    let private selectRuntime (config : RuntimeOptions) (f : DotnetEnvironmentInfo) : DirectoryInfo list =
         let rollForward =
             match Environment.GetEnvironmentVariable "DOTNET_ROLL_FORWARD" with
             | null ->
@@ -20,6 +16,14 @@ module DotnetRuntime =
                 |> Option.defaultValue RollForward.Minor
             | s -> RollForward.Parse s
 
+        if
+            Option.isSome config.IncludedFramework
+            || Option.isSome config.IncludedFrameworks
+        then
+            // No need for a framework that's anywhere other than the given DLL.
+            []
+        else
+
         let desiredVersions =
             match config.Framework with
             | Some f -> [ Version f.Version, f.Name ]
@@ -66,15 +70,13 @@ module DotnetRuntime =
 
                     name, data.Installed
                 )
-                // TODO: how do we select between many available frameworks?
-                |> Seq.tryHead
+                |> Seq.toList
 
-            match available with
-            | Some (_, f) -> Some (Choice1Of2 f)
-            | None ->
-                // TODO: maybe we can ask the SDK. But we keep on trucking: maybe we're self-contained,
-                // and we'll actually find all the runtime next to the DLL.
-                None
+            // TODO: maybe we can ask the SDK if we don't have any runtimes.
+            // But we keep on trucking: maybe we're self-contained, and we'll actually find all the runtime next to the
+            // DLL.
+            available
+            |> List.map (fun (_name, runtime) -> DirectoryInfo $"%s{runtime.Path}/%s{runtime.Version}")
         | _ -> failwith "non-minor RollForward not supported yet; please shout if you want it"
 
     /// Given an executable DLL, locate the .NET runtime that can best run it.
@@ -96,9 +98,4 @@ module DotnetRuntime =
 
         let runtime = selectRuntime runtimeConfig availableRuntimes
 
-        match runtime with
-        | None ->
-            // Keep on trucking: let's be optimistic and hope that we're self-contained.
-            [ dll.Directory ]
-        | Some (Choice1Of2 runtime) -> [ dll.Directory ; DirectoryInfo $"%s{runtime.Path}/%s{runtime.Version}" ]
-        | Some (Choice2Of2 sdk) -> [ dll.Directory ; DirectoryInfo sdk.Path ]
+        dll.Directory :: runtime

WoofWare.NUnitTestRunner.Lib/Filter.fs

@@ -2,7 +2,7 @@ namespace WoofWare.NUnitTestRunner
 
 open System
 open System.IO
-open PrattParser
+open WoofWare.PrattParser
 
 // Documentation:
 // https://learn.microsoft.com/en-us/dotnet/core/testing/selective-unit-tests?pivots=mstest

WoofWare.NUnitTestRunner.Lib/ParallelQueue.fs

@@ -36,66 +36,311 @@ type TestFixtureTearDownToken = private | TestFixtureTearDownToken of TestFixtur
 module private TestFixtureTearDownToken =
     let vouchNoTearDownRequired (TestFixtureSetupToken tf) = TestFixtureTearDownToken tf
 
+[<RequireQualifiedAccess>]
 type private MailboxMessage =
     | Quit of AsyncReplyChannel<unit>
-    | RunTest of ThunkCrate
+    /// Check current state, see if we need to start more tests, etc.
+    | Reconcile
+    | RunTest of within : TestFixture * Parallelizable<unit> option * test : ThunkCrate
     | BeginTestFixture of TestFixture * AsyncReplyChannel<TestFixtureRunningToken>
     | EndTestFixture of TestFixtureTearDownToken * AsyncReplyChannel<unit>
 
+type private RunningFixture =
+    {
+        Fixture : TestFixture
+        RunningCanParallelize : bool
+        Running : Task list
+        Waiting : ((unit -> Task) * Parallelizable<unit> option) list
+    }
+
+    static member Make (f : TestFixture) =
+        {
+            Fixture = f
+            Running = []
+            RunningCanParallelize = true
+            Waiting = []
+        }
+
+type private RunningState =
+    {
+        MaxParallelism : int
+        // TODO: make these efficiently look-up-able
+        CurrentlyRunning : RunningFixture list
+        Waiting : (TestFixture * AsyncReplyChannel<TestFixtureRunningToken>) list
+    }
+
+    member this.NewTest (tf : TestFixture) (par : Parallelizable<unit> option) (test : unit -> Task) =
+        {
+            MaxParallelism = this.MaxParallelism
+            Waiting = this.Waiting
+            CurrentlyRunning =
+                let found = ref 0
+
+                this.CurrentlyRunning
+                |> List.map (fun f ->
+                    if Object.ReferenceEquals (f.Fixture, tf) then
+                        Interlocked.Increment found |> ignore<int>
+
+                        { f with
+                            Waiting = (test, par) :: f.Waiting
+                        }
+                    else
+                        f
+                )
+                |> fun l ->
+                    match found.Value with
+                    | 1 -> l
+                    | 0 -> failwith $"Unexpectedly did not find the running test fixture '%s{tf.Name}' to add a test to"
+                    | _ -> failwith $"Unexpectedly found the running test fixture '%s{tf.Name}' multiple times in list"
+        }
+
+    member this.CompleteFixture (tf : TestFixture) : RunningState =
+        let rec go (acc : RunningFixture list) (running : RunningFixture list) =
+            match running with
+            | [] -> failwith "Caller has somehow called EndTestFixture while we're not running that test fixture"
+            | runningFixture :: tail ->
+                if Object.ReferenceEquals (runningFixture.Fixture, tf) then
+                    match runningFixture.Running, runningFixture.Waiting with
+                    | [], [] -> acc @ tail
+                    | r, [] ->
+                        failwith $"Caller has called EndTestFixture while its tests are still running (%i{r.Length})"
+                    | [], r ->
+                        failwith $"Caller has called EndTestFixture while it has tests waiting to run (%i{r.Length})"
+                    | r, s ->
+                        failwith
+                            $"Caller has called EndTestFixture while it has tests waiting to run (%i{s.Length}) and test running (%i{r.Length})"
+                else
+                    go (runningFixture :: acc) tail
+
+        let currentlyRunning = go [] this.CurrentlyRunning
+
+        {
+            CurrentlyRunning = currentlyRunning
+            Waiting = this.Waiting
+            MaxParallelism = this.MaxParallelism
+        }
+
 type private MailboxState =
     | Idle
-    | Running of TestFixture * (TestFixture * AsyncReplyChannel<TestFixtureRunningToken>) list
+    | Running of RunningState
 
 /// Run some things in parallel.
 /// TODO: actually implement the parallelism! Right now this just runs everything serially.
 /// TODO: consume the cancellation token
 type ParallelQueue
-    (_parallelism : int option, _scope : Parallelizable<AssemblyParallelScope> option, ?ct : CancellationToken)
+    (parallelism : int option, _scope : Parallelizable<AssemblyParallelScope> option, ?ct : CancellationToken)
     =
+    let parallelism =
+        match parallelism with
+        | None -> max (Environment.ProcessorCount / 2) 2
+        | Some p -> p
+
     let rec processTask (state : MailboxState) (m : MailboxProcessor<MailboxMessage>) =
         async {
             let! message = m.Receive ()
 
             match message with
-            | Quit rc -> rc.Reply ()
-            | BeginTestFixture (tf, rc) ->
+            | MailboxMessage.Quit rc -> rc.Reply ()
+            | MailboxMessage.Reconcile ->
                 match state with
-                | Running (current, rest) ->
-                    let state = Running (current, (tf, rc) :: rest)
-                    return! processTask state m
-                | Idle ->
-                    let state = Running (tf, [])
-                    rc.Reply (TestFixtureRunningToken tf)
-                    return! processTask state m
-            | EndTestFixture (TestFixtureTearDownToken tf, rc) ->
-                match state with
-                | Idle ->
-                    return failwith "Caller has somehow called EndTestFixture while we're not running a test fixture"
-                | Running (current, rest) ->
-                    if not (Object.ReferenceEquals (current, tf)) then
-                        return
-                            failwith
-                                "Caller has somehow called EndTestFixture while we're not running that test fixture"
+                | Idle -> return! processTask state m
+                | Running r ->
 
-                    rc.Reply ()
-
-                    match rest with
+                match r.CurrentlyRunning with
+                | [] ->
+                    match r.Waiting with
                     | [] -> return! processTask Idle m
                     | (head, rc) :: tail ->
                         rc.Reply (TestFixtureRunningToken head)
-                        return! processTask (Running (head, tail)) m
-            | RunTest message ->
-                // Currently we rely on the caller to only send this message when we've given them permission through
-                // the StartTestFixture method returning.
-                { new ThunkEvaluator<_> with
-                    member _.Eval t rc =
-                        use ec = ExecutionContext.Capture ()
-                        ExecutionContext.Run (ec, (fun _ -> rc.Reply (t ())), ())
-                        FakeUnit
-                }
-                |> message.Apply
-                |> function
-                    | FakeUnit -> ()
+
+                        let newRunning =
+                            {
+                                Fixture = head
+                                Running = []
+                                RunningCanParallelize = true
+                                Waiting = []
+                            }
+
+                        let state =
+                            {
+                                MaxParallelism = r.MaxParallelism
+                                CurrentlyRunning = [ newRunning ]
+                                Waiting = tail
+                            }
+                        // For now, we'll just run one fixture at a time. When we run multiple fixtures in parallel,
+                        // we probably want to call Reconcile here again.
+                        return! processTask (Running state) m
+                | [ currentlyRunning ] ->
+                    let currentlyRunningTasks =
+                        currentlyRunning.Running |> List.filter (fun t -> not t.IsCompleted)
+
+                    let r =
+                        { r with
+                            CurrentlyRunning =
+                                [
+                                    { currentlyRunning with
+                                        Running = currentlyRunningTasks
+                                    }
+                                ]
+                        }
+
+                    match currentlyRunningTasks with
+                    | [] ->
+                        match currentlyRunning.Waiting with
+                        | [] ->
+                            // Nothing to run yet
+                            return! processTask (Running r) m
+                        | (head, par) :: tail ->
+                            let par =
+                                match par with
+                                | None -> true
+                                | Some Parallelizable.No -> false
+                                | Some (Parallelizable.Yes ()) -> true
+
+                            let state =
+                                {
+                                    Fixture = currentlyRunning.Fixture
+                                    RunningCanParallelize = par
+                                    Waiting = tail
+                                    Running = [ head () ]
+                                }
+
+                            m.Post MailboxMessage.Reconcile
+
+                            return!
+                                processTask
+                                    (Running
+                                        { r with
+                                            CurrentlyRunning = [ state ]
+                                        })
+                                    m
+
+                    | currentlyRunningTasks ->
+
+                    if currentlyRunningTasks.Length >= parallelism then
+                        return! processTask (Running r) m
+                    else
+
+                    match currentlyRunning.Waiting, currentlyRunning.RunningCanParallelize with
+                    | [], _ ->
+                        // No new candidates.
+                        return! processTask (Running r) m
+                    | _, false ->
+                        // The running test(s) can't have others added.
+                        return! processTask (Running r) m
+                    | (head, par) :: tail, true ->
+                        match par with
+                        | Some Parallelizable.No -> return! processTask (Running r) m
+                        | Some (Parallelizable.Yes ()) ->
+                            let state =
+                                {
+                                    RunningState.MaxParallelism = r.MaxParallelism
+                                    Waiting = r.Waiting
+                                    CurrentlyRunning =
+                                        [
+                                            {
+                                                Fixture = currentlyRunning.Fixture
+                                                RunningCanParallelize = true
+                                                Running = head () :: currentlyRunning.Running
+                                                Waiting = tail
+                                            }
+                                        ]
+                                }
+
+                            m.Post MailboxMessage.Reconcile
+                            return! processTask (Running state) m
+                        | None ->
+                            match currentlyRunning.Fixture.Parallelize with
+                            | Some Parallelizable.No
+                            | Some (Parallelizable.Yes ClassParallelScope.Self)
+                            | Some (Parallelizable.Yes ClassParallelScope.Fixtures) ->
+                                // Can't add this test to the parallel queue right now
+                                return! processTask (Running r) m
+                            | None
+                            | Some (Parallelizable.Yes ClassParallelScope.All)
+                            | Some (Parallelizable.Yes ClassParallelScope.Children) ->
+                                let state =
+                                    {
+                                        Fixture = currentlyRunning.Fixture
+                                        RunningCanParallelize = true
+                                        Waiting = tail
+                                        Running = (head ()) :: currentlyRunningTasks
+                                    }
+
+                                m.Post MailboxMessage.Reconcile
+
+                                return!
+                                    processTask
+                                        (Running
+                                            { r with
+                                                CurrentlyRunning = [ state ]
+                                            })
+                                        m
+                | _ -> failwith "Logic error: we currently only run one fixture at a time"
+            | MailboxMessage.BeginTestFixture (tf, rc) ->
+                match state with
+                | Running state ->
+                    let state =
+                        {
+                            MaxParallelism = state.MaxParallelism
+                            CurrentlyRunning = state.CurrentlyRunning
+                            Waiting = (tf, rc) :: state.Waiting
+                        }
+                        |> Running
+
+                    m.Post MailboxMessage.Reconcile
+                    return! processTask state m
+                | Idle ->
+                    let state =
+                        {
+                            MaxParallelism = parallelism
+                            CurrentlyRunning = []
+                            Waiting = [ (tf, rc) ]
+                        }
+                        |> Running
+
+                    m.Post MailboxMessage.Reconcile
+                    return! processTask state m
+            | MailboxMessage.EndTestFixture (TestFixtureTearDownToken tf, rc) ->
+                match state with
+                | Idle ->
+                    return failwith "Caller has somehow called EndTestFixture while we're not running a test fixture"
+                | Running state ->
+                    let state = state.CompleteFixture tf
+                    rc.Reply ()
+                    m.Post MailboxMessage.Reconcile
+                    return! processTask (Running state) m
+            | MailboxMessage.RunTest (withinFixture, par, message) ->
+                let t () =
+                    { new ThunkEvaluator<_> with
+                        member _.Eval<'b> (t : unit -> 'b) rc =
+                            let tcs = TaskCompletionSource ()
+                            use ec = ExecutionContext.Capture ()
+
+                            fun () ->
+                                ExecutionContext.Run (
+                                    ec,
+                                    (fun _ ->
+                                        let result = t ()
+                                        tcs.SetResult ()
+                                        m.Post MailboxMessage.Reconcile
+                                        rc.Reply result
+                                    ),
+                                    ()
+                                )
+                            |> Task.Factory.StartNew
+                            |> ignore<Task>
+
+                            tcs.Task
+                    }
+                    |> message.Apply
+
+                let state =
+                    match state with
+                    | Idle -> failwith "somehow asked the queue to run tests when there is no active fixture"
+                    | Running state -> state.NewTest withinFixture par t |> Running
+
+                m.Post MailboxMessage.Reconcile
 
                 return! processTask state m
         }
@@ -103,50 +348,75 @@ type ParallelQueue
     let mb = new MailboxProcessor<_> (processTask MailboxState.Idle)
     do mb.Start ()
 
-    /// Request to run the given action on its own, not in parallel with anything else.
-    /// The resulting Task will return when the action has completed.
-    member _.NonParallel<'a> (parent : TestFixtureSetupToken) (action : unit -> 'a) : 'a Task =
-        ThunkCrate.make action >> RunTest |> mb.PostAndAsyncReply |> Async.StartAsTask
-
     /// Request to run the given action, freely in parallel with other running tests.
     /// The resulting Task will return when the action has completed.
-    member _.Parallel<'a> (parent : TestFixtureSetupToken) (action : unit -> 'a) : 'a Task =
-        ThunkCrate.make action >> RunTest |> mb.PostAndAsyncReply |> Async.StartAsTask
-
-    /// Request to run the given action, obeying the parallelism constraints of the parent test fixture.
-    /// The resulting Task will return when the action has completed.
-    member _.ObeyParent<'a> (tf : TestFixtureSetupToken) (action : unit -> 'a) : 'a Task =
-        ThunkCrate.make action >> RunTest |> mb.PostAndAsyncReply |> Async.StartAsTask
+    member _.Run<'a>
+        (TestFixtureSetupToken parent)
+        (scope : Parallelizable<unit> option)
+        (action : unit -> 'a)
+        : 'a Task
+        =
+        (fun rc -> MailboxMessage.RunTest (parent, scope, ThunkCrate.make action rc))
+        |> mb.PostAndAsyncReply
+        |> Async.StartAsTask
 
     /// Declare that we wish to start the given test fixture. The resulting Task will return
     /// when you are allowed to start running tests from that fixture.
     /// Once you've finished running tests from that fixture, call EndTestFixture.
     member _.StartTestFixture (tf : TestFixture) : Task<TestFixtureRunningToken> =
-        fun rc -> BeginTestFixture (tf, rc)
+        fun rc -> MailboxMessage.BeginTestFixture (tf, rc)
         |> mb.PostAndAsyncReply
         |> Async.StartAsTask
 
     /// Run the given one-time setup for the test fixture.
-    member _.RunTestSetup (TestFixtureRunningToken tf) (action : unit -> 'a) : ('a * TestFixtureSetupToken) Task =
+    member _.RunTestSetup (TestFixtureRunningToken parent) (action : unit -> 'a) : ('a * TestFixtureSetupToken) Task =
         task {
-            let! response = ThunkCrate.make action >> RunTest |> mb.PostAndAsyncReply
-            return response, TestFixtureSetupToken tf
+            let par =
+                parent.Parallelize
+                |> Option.map (fun p ->
+                    match p with
+                    | Parallelizable.No -> Parallelizable.No
+                    | Parallelizable.Yes _ -> Parallelizable.Yes ()
+                )
+
+            let! response =
+                (fun rc -> MailboxMessage.RunTest (parent, par, ThunkCrate.make action rc))
+                |> mb.PostAndAsyncReply
+
+            return response, TestFixtureSetupToken parent
         }
 
     /// Run the given one-time tear-down for the test fixture.
-    member _.RunTestTearDown (TestFixtureSetupToken tf) (action : unit -> 'a) : ('a * TestFixtureTearDownToken) Task =
+    member _.RunTestTearDown
+        (TestFixtureSetupToken parent)
+        (action : unit -> 'a)
+        : ('a * TestFixtureTearDownToken) Task
+        =
         task {
-            let! response = ThunkCrate.make action >> RunTest |> mb.PostAndAsyncReply
-            return response, TestFixtureTearDownToken tf
+            let par =
+                parent.Parallelize
+                |> Option.map (fun p ->
+                    match p with
+                    | Parallelizable.No -> Parallelizable.No
+                    | Parallelizable.Yes _ -> Parallelizable.Yes ()
+                )
+
+            let! response =
+                (fun rc -> MailboxMessage.RunTest (parent, par, ThunkCrate.make action rc))
+                |> mb.PostAndAsyncReply
+
+            return response, TestFixtureTearDownToken parent
         }
 
     /// Declare that we have finished submitting requests to run in the given test fixture.
     /// You don't need to worry about when the resulting Task returns, but we provide it just in case.
     member _.EndTestFixture (tf : TestFixtureTearDownToken) : Task<unit> =
-        (fun rc -> EndTestFixture (tf, rc)) |> mb.PostAndAsyncReply |> Async.StartAsTask
+        (fun rc -> MailboxMessage.EndTestFixture (tf, rc))
+        |> mb.PostAndAsyncReply
+        |> Async.StartAsTask
 
     interface IDisposable with
         member _.Dispose () =
             // Still race conditions, of course: people could still be submitting after we finish the sync.
-            mb.PostAndReply Quit
+            mb.PostAndReply MailboxMessage.Quit
             (mb :> IDisposable).Dispose ()

WoofWare.NUnitTestRunner.Lib/RuntimeConfig.fs

@@ -16,6 +16,8 @@ type internal RuntimeOptions =
         Tfm : string
         Framework : FrameworkDescription option
         Frameworks : FrameworkDescription list option
+        IncludedFramework : FrameworkDescription option
+        IncludedFrameworks : FrameworkDescription list option
         RollForward : string option
     }
 

WoofWare.NUnitTestRunner.Lib/SurfaceBaseline.txt

@@ -1,3 +1,26 @@
+WoofWare.NUnitTestRunner.Args inherit obj, implements WoofWare.NUnitTestRunner.Args System.IEquatable, System.Collections.IStructuralEquatable
+WoofWare.NUnitTestRunner.Args..ctor [constructor]: (System.IO.FileInfo, System.IO.FileInfo option, (string * WoofWare.NUnitTestRunner.Filter) option, WoofWare.NUnitTestRunner.LogLevel, int option, System.TimeSpan option)
+WoofWare.NUnitTestRunner.Args.Dll [property]: [read-only] System.IO.FileInfo
+WoofWare.NUnitTestRunner.Args.Filter [property]: [read-only] (string * WoofWare.NUnitTestRunner.Filter) option
+WoofWare.NUnitTestRunner.Args.get_Dll [method]: unit -> System.IO.FileInfo
+WoofWare.NUnitTestRunner.Args.get_Filter [method]: unit -> (string * WoofWare.NUnitTestRunner.Filter) option
+WoofWare.NUnitTestRunner.Args.get_LevelOfParallelism [method]: unit -> int option
+WoofWare.NUnitTestRunner.Args.get_Logging [method]: unit -> WoofWare.NUnitTestRunner.LogLevel
+WoofWare.NUnitTestRunner.Args.get_Timeout [method]: unit -> System.TimeSpan option
+WoofWare.NUnitTestRunner.Args.get_Trx [method]: unit -> System.IO.FileInfo option
+WoofWare.NUnitTestRunner.Args.LevelOfParallelism [property]: [read-only] int option
+WoofWare.NUnitTestRunner.Args.Logging [property]: [read-only] WoofWare.NUnitTestRunner.LogLevel
+WoofWare.NUnitTestRunner.Args.Parse [static method]: string list -> WoofWare.NUnitTestRunner.Args
+WoofWare.NUnitTestRunner.Args.Timeout [property]: [read-only] System.TimeSpan option
+WoofWare.NUnitTestRunner.Args.Trx [property]: [read-only] System.IO.FileInfo option
+WoofWare.NUnitTestRunner.AssemblyLevelAttributes inherit obj, implements WoofWare.NUnitTestRunner.AssemblyLevelAttributes System.IEquatable, System.Collections.IStructuralEquatable, WoofWare.NUnitTestRunner.AssemblyLevelAttributes System.IComparable, System.IComparable, System.Collections.IStructuralComparable
+WoofWare.NUnitTestRunner.AssemblyLevelAttributes..ctor [constructor]: (int option, WoofWare.NUnitTestRunner.AssemblyParallelScope WoofWare.NUnitTestRunner.Parallelizable option)
+WoofWare.NUnitTestRunner.AssemblyLevelAttributes.get_Parallelism [method]: unit -> int option
+WoofWare.NUnitTestRunner.AssemblyLevelAttributes.get_Parallelizable [method]: unit -> WoofWare.NUnitTestRunner.AssemblyParallelScope WoofWare.NUnitTestRunner.Parallelizable option
+WoofWare.NUnitTestRunner.AssemblyLevelAttributes.Parallelism [property]: [read-only] int option
+WoofWare.NUnitTestRunner.AssemblyLevelAttributes.Parallelizable [property]: [read-only] WoofWare.NUnitTestRunner.AssemblyParallelScope WoofWare.NUnitTestRunner.Parallelizable option
+WoofWare.NUnitTestRunner.AssemblyLevelAttributesModule inherit obj
+WoofWare.NUnitTestRunner.AssemblyLevelAttributesModule.get [static method]: System.Reflection.Assembly -> WoofWare.NUnitTestRunner.AssemblyLevelAttributes
 WoofWare.NUnitTestRunner.AssemblyParallelScope inherit obj, implements WoofWare.NUnitTestRunner.AssemblyParallelScope System.IEquatable, System.Collections.IStructuralEquatable, WoofWare.NUnitTestRunner.AssemblyParallelScope System.IComparable, System.IComparable, System.Collections.IStructuralComparable - union type with 2 cases
 WoofWare.NUnitTestRunner.AssemblyParallelScope+Tags inherit obj
 WoofWare.NUnitTestRunner.AssemblyParallelScope+Tags.Children [static field]: int = 0
@@ -12,6 +35,8 @@ WoofWare.NUnitTestRunner.AssemblyParallelScope.get_Tag [method]: unit -> int
 WoofWare.NUnitTestRunner.AssemblyParallelScope.IsChildren [property]: [read-only] bool
 WoofWare.NUnitTestRunner.AssemblyParallelScope.IsFixtures [property]: [read-only] bool
 WoofWare.NUnitTestRunner.AssemblyParallelScope.Tag [property]: [read-only] int
+WoofWare.NUnitTestRunner.BuildTrxReport inherit obj
+WoofWare.NUnitTestRunner.BuildTrxReport.build [static method]: System.Reflection.Assembly -> System.DateTimeOffset -> System.DateTimeOffset -> WoofWare.NUnitTestRunner.FixtureRunResults list -> WoofWare.NUnitTestRunner.TrxReport
 WoofWare.NUnitTestRunner.ClassParallelScope inherit obj, implements WoofWare.NUnitTestRunner.ClassParallelScope System.IEquatable, System.Collections.IStructuralEquatable, WoofWare.NUnitTestRunner.ClassParallelScope System.IComparable, System.IComparable, System.Collections.IStructuralComparable - union type with 4 cases
 WoofWare.NUnitTestRunner.ClassParallelScope+Tags inherit obj
 WoofWare.NUnitTestRunner.ClassParallelScope+Tags.All [static field]: int = 3
@@ -145,6 +170,20 @@ WoofWare.NUnitTestRunner.ITestProgress.OnTestMemberSkipped [method]: string -> u
 WoofWare.NUnitTestRunner.ITestProgress.OnTestMemberStart [method]: string -> unit
 WoofWare.NUnitTestRunner.LoadContext inherit System.Runtime.Loader.AssemblyLoadContext
 WoofWare.NUnitTestRunner.LoadContext..ctor [constructor]: (System.IO.FileInfo, System.IO.DirectoryInfo list, WoofWare.NUnitTestRunner.TestContexts)
+WoofWare.NUnitTestRunner.LogLevel inherit obj, implements WoofWare.NUnitTestRunner.LogLevel System.IEquatable, System.Collections.IStructuralEquatable, WoofWare.NUnitTestRunner.LogLevel System.IComparable, System.IComparable, System.Collections.IStructuralComparable - union type with 2 cases
+WoofWare.NUnitTestRunner.LogLevel+Tags inherit obj
+WoofWare.NUnitTestRunner.LogLevel+Tags.Nothing [static field]: int = 0
+WoofWare.NUnitTestRunner.LogLevel+Tags.Verbose [static field]: int = 1
+WoofWare.NUnitTestRunner.LogLevel.get_IsNothing [method]: unit -> bool
+WoofWare.NUnitTestRunner.LogLevel.get_IsVerbose [method]: unit -> bool
+WoofWare.NUnitTestRunner.LogLevel.get_Nothing [static method]: unit -> WoofWare.NUnitTestRunner.LogLevel
+WoofWare.NUnitTestRunner.LogLevel.get_Tag [method]: unit -> int
+WoofWare.NUnitTestRunner.LogLevel.get_Verbose [static method]: unit -> WoofWare.NUnitTestRunner.LogLevel
+WoofWare.NUnitTestRunner.LogLevel.IsNothing [property]: [read-only] bool
+WoofWare.NUnitTestRunner.LogLevel.IsVerbose [property]: [read-only] bool
+WoofWare.NUnitTestRunner.LogLevel.Nothing [static property]: [read-only] WoofWare.NUnitTestRunner.LogLevel
+WoofWare.NUnitTestRunner.LogLevel.Tag [property]: [read-only] int
+WoofWare.NUnitTestRunner.LogLevel.Verbose [static property]: [read-only] WoofWare.NUnitTestRunner.LogLevel
 WoofWare.NUnitTestRunner.Match inherit obj, implements WoofWare.NUnitTestRunner.Match System.IEquatable, System.Collections.IStructuralEquatable, WoofWare.NUnitTestRunner.Match System.IComparable, System.IComparable, System.Collections.IStructuralComparable - union type with 2 cases
 WoofWare.NUnitTestRunner.Match+Contains inherit WoofWare.NUnitTestRunner.Match
 WoofWare.NUnitTestRunner.Match+Contains.get_Item [method]: unit -> string
@@ -200,9 +239,7 @@ WoofWare.NUnitTestRunner.Parallelizable`1.Tag [property]: [read-only] int
 WoofWare.NUnitTestRunner.ParallelQueue inherit obj, implements IDisposable
 WoofWare.NUnitTestRunner.ParallelQueue..ctor [constructor]: (int option, WoofWare.NUnitTestRunner.AssemblyParallelScope WoofWare.NUnitTestRunner.Parallelizable option, System.Threading.CancellationToken option)
 WoofWare.NUnitTestRunner.ParallelQueue.EndTestFixture [method]: WoofWare.NUnitTestRunner.TestFixtureTearDownToken -> unit System.Threading.Tasks.Task
-WoofWare.NUnitTestRunner.ParallelQueue.NonParallel [method]: WoofWare.NUnitTestRunner.TestFixtureSetupToken -> (unit -> 'a) -> 'a System.Threading.Tasks.Task
-WoofWare.NUnitTestRunner.ParallelQueue.ObeyParent [method]: WoofWare.NUnitTestRunner.TestFixtureSetupToken -> (unit -> 'a) -> 'a System.Threading.Tasks.Task
-WoofWare.NUnitTestRunner.ParallelQueue.Parallel [method]: WoofWare.NUnitTestRunner.TestFixtureSetupToken -> (unit -> 'a) -> 'a System.Threading.Tasks.Task
+WoofWare.NUnitTestRunner.ParallelQueue.Run [method]: WoofWare.NUnitTestRunner.TestFixtureSetupToken -> unit WoofWare.NUnitTestRunner.Parallelizable option -> (unit -> 'a) -> 'a System.Threading.Tasks.Task
 WoofWare.NUnitTestRunner.ParallelQueue.RunTestSetup [method]: WoofWare.NUnitTestRunner.TestFixtureRunningToken -> (unit -> 'a) -> ('a * WoofWare.NUnitTestRunner.TestFixtureSetupToken) System.Threading.Tasks.Task
 WoofWare.NUnitTestRunner.ParallelQueue.RunTestTearDown [method]: WoofWare.NUnitTestRunner.TestFixtureSetupToken -> (unit -> 'a) -> ('a * WoofWare.NUnitTestRunner.TestFixtureTearDownToken) System.Threading.Tasks.Task
 WoofWare.NUnitTestRunner.ParallelQueue.StartTestFixture [method]: WoofWare.NUnitTestRunner.TestFixture -> WoofWare.NUnitTestRunner.TestFixtureRunningToken System.Threading.Tasks.Task
@@ -228,6 +265,10 @@ WoofWare.NUnitTestRunner.SingleTestMethodModule inherit obj
 WoofWare.NUnitTestRunner.SingleTestMethodModule.parse [static method]: string list -> System.Reflection.MethodInfo -> System.Reflection.CustomAttributeData list -> (WoofWare.NUnitTestRunner.SingleTestMethod option * System.Reflection.CustomAttributeData list)
 WoofWare.NUnitTestRunner.TestContexts inherit obj, implements WoofWare.NUnitTestRunner.TestContexts System.IEquatable, System.Collections.IStructuralEquatable, IDisposable
 WoofWare.NUnitTestRunner.TestContexts.Empty [static method]: unit -> WoofWare.NUnitTestRunner.TestContexts
+WoofWare.NUnitTestRunner.TestContexts.get_Stderr [method]: unit -> System.IO.TextWriter
+WoofWare.NUnitTestRunner.TestContexts.get_Stdout [method]: unit -> System.IO.TextWriter
+WoofWare.NUnitTestRunner.TestContexts.Stderr [property]: [read-only] System.IO.TextWriter
+WoofWare.NUnitTestRunner.TestContexts.Stdout [property]: [read-only] System.IO.TextWriter
 WoofWare.NUnitTestRunner.TestFailure inherit obj, implements WoofWare.NUnitTestRunner.TestFailure System.IEquatable, System.Collections.IStructuralEquatable - union type with 3 cases
 WoofWare.NUnitTestRunner.TestFailure+SetUpFailed inherit WoofWare.NUnitTestRunner.TestFailure
 WoofWare.NUnitTestRunner.TestFailure+SetUpFailed.get_Item [method]: unit -> WoofWare.NUnitTestRunner.UserMethodFailure
@@ -358,6 +399,7 @@ WoofWare.NUnitTestRunner.TestMemberSuccess.Ok [static property]: [read-only] Woo
 WoofWare.NUnitTestRunner.TestMemberSuccess.Tag [property]: [read-only] int
 WoofWare.NUnitTestRunner.TestProgress inherit obj
 WoofWare.NUnitTestRunner.TestProgress.toStderr [static method]: unit -> WoofWare.NUnitTestRunner.ITestProgress
+WoofWare.NUnitTestRunner.TestProgress.toWriter [static method]: System.IO.TextWriter -> WoofWare.NUnitTestRunner.ITestProgress
 WoofWare.NUnitTestRunner.TrxCounters inherit obj, implements WoofWare.NUnitTestRunner.TrxCounters System.IEquatable, System.Collections.IStructuralEquatable
 WoofWare.NUnitTestRunner.TrxCounters..ctor [constructor]: (System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32, System.UInt32)
 WoofWare.NUnitTestRunner.TrxCounters.Aborted [property]: [read-only] System.UInt32

WoofWare.NUnitTestRunner.Lib/TestFixture.fs

@@ -401,11 +401,7 @@ module TestFixture =
 
                     result, meta
 
-                let! results, summary =
-                    match test.Parallelize with
-                    | Some Parallelizable.No -> par.NonParallel running runMe
-                    | Some (Parallelizable.Yes _) -> par.Parallel running runMe
-                    | None -> par.ObeyParent running runMe
+                let! results, summary = par.Run running test.Parallelize runMe
 
                 match results with
                 | Ok results -> return Ok results, summary

WoofWare.NUnitTestRunner.Lib/TestProgress.fs

@@ -1,6 +1,7 @@
 namespace WoofWare.NUnitTestRunner
 
 open System
+open System.IO
 
 /// Represents something which knows how to report progress through a test suite.
 /// Note that we don't guarantee anything about parallelism; you must make sure
@@ -24,22 +25,25 @@ type ITestProgress =
 /// Methods for constructing specific ITestProgress objects.
 [<RequireQualifiedAccess>]
 module TestProgress =
-    /// An ITestProgress which logs to stderr.
-    let toStderr () : ITestProgress =
+    /// An ITestProgress which logs to the given writer.
+    let toWriter (writer : TextWriter) : ITestProgress =
         { new ITestProgress with
             member _.OnTestFixtureStart name testCount =
                 let plural = if testCount = 1 then "" else "s"
-                Console.Error.WriteLine $"Running test fixture: %s{name} (%i{testCount} test%s{plural} to run)"
+                writer.WriteLine $"Running test fixture: %s{name} (%i{testCount} test%s{plural} to run)"
 
             member _.OnTestMemberStart name =
-                Console.Error.WriteLine $"Running test: %s{name}"
+                writer.WriteLine $"Running test: %s{name}"
 
             member _.OnTestFailed name failure =
-                Console.Error.WriteLine $"Test failed: %O{failure}"
+                writer.WriteLine $"Test failed: %O{failure}"
 
             member _.OnTestMemberFinished name =
-                Console.Error.WriteLine $"Finished test %s{name}"
+                writer.WriteLine $"Finished test %s{name}"
 
             member _.OnTestMemberSkipped name =
-                Console.Error.WriteLine $"Skipping test due to filter: %s{name}"
+                writer.WriteLine $"Skipping test due to filter: %s{name}"
         }
+
+    /// An ITestProgress which logs to stderr.
+    let toStderr () : ITestProgress = toWriter Console.Error

WoofWare.NUnitTestRunner.Lib/WoofWare.NUnitTestRunner.Lib.fsproj

@@ -14,7 +14,7 @@
       <PackageId>WoofWare.NUnitTestRunner.Lib</PackageId>
       <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
       <WarnOn>FS3559</WarnOn>
-      <WoofWareMyriadPluginVersion>2.1.44</WoofWareMyriadPluginVersion>
+      <WoofWareMyriadPluginVersion>2.1.45</WoofWareMyriadPluginVersion>
     </PropertyGroup>
 
     <ItemGroup>
@@ -29,6 +29,7 @@
       <Compile Include="Result.fs" />
       <Compile Include="Domain.fs" />
       <Compile Include="Filter.fs" />
+      <Compile Include="Args.fs" />
       <Compile Include="ParallelQueue.fs" />
       <Compile Include="SingleTestMethod.fs" />
       <Compile Include="TestProgress.fs" />
@@ -36,6 +37,8 @@
       <Compile Include="TestFixture.fs" />
       <Compile Include="Xml.fs" />
       <Compile Include="TrxReport.fs" />
+      <Compile Include="CreateTrxReport.fs" />
+      <Compile Include="AssemblyLevelAttributes.fs" />
       <None Include="..\README.md">
         <Pack>True</Pack>
         <PackagePath>\</PackagePath>
@@ -44,14 +47,14 @@
       <EmbeddedResource Include="version.json" />
     </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="WoofWare.PrattParser" Version="0.1.2" />
+    <PackageReference Include="WoofWare.PrattParser" Version="0.2.2" />
     <PackageReference Update="FSharp.Core" Version="6.0.0" />
-    <PackageReference Include="WoofWare.DotnetRuntimeLocator" Version="0.1.4" />
-    <PackageReference Include="WoofWare.Myriad.Plugins.Attributes" Version="3.1.6" />
-    <PackageReference Include="Myriad.SDK" Version="0.8.3" />
+    <PackageReference Include="WoofWare.DotnetRuntimeLocator" Version="0.1.9" />
+    <PackageReference Include="WoofWare.Myriad.Plugins.Attributes" Version="3.1.7" />
+    <PackageReference Include="Myriad.SDK" Version="0.8.3" PrivateAssets="all" />
     <PackageReference Include="WoofWare.Myriad.Plugins" Version="$(WoofWareMyriadPluginVersion)" PrivateAssets="all" />
   </ItemGroup>
-  
+
   <ItemGroup>
     <MyriadSdkGenerator Include="$(NuGetPackageRoot)/woofware.myriad.plugins/$(WoofWareMyriadPluginVersion)/lib/net6.0/WoofWare.Myriad.Plugins.dll" />
   </ItemGroup>

WoofWare.NUnitTestRunner.Lib/version.json

@@ -1,5 +1,5 @@
 {
-  "version": "0.13",
+  "version": "0.16",
   "publicReleaseRefSpec": [
     "^refs/heads/main$"
   ],
@@ -8,4 +8,4 @@
     ":/Directory.Build.props",
     ":/README.md"
   ]
-}
+}

WoofWare.NUnitTestRunner.StartupHook/StartupHook.cs

@@ -0,0 +1,35 @@
+using System.Linq;
+using System.Reflection;
+using System.Runtime.Loader;
+using WoofWare.NUnitTestRunner.StartupHook;
+
+namespace WoofWare.NUnitTestRunner.StartupHook
+{
+    internal class StartupAssemblyLoadContext : AssemblyLoadContext
+    {
+        private readonly AssemblyDependencyResolver _resolver;
+
+        public StartupAssemblyLoadContext()
+        {
+            _resolver = new AssemblyDependencyResolver(Assembly.GetExecutingAssembly().Location);
+        }
+
+        protected override Assembly Load(AssemblyName assemblyName)
+        {
+            var assemblyPath = _resolver.ResolveAssemblyToPath(assemblyName);
+
+            return assemblyPath != null ? LoadFromAssemblyPath(assemblyPath) : null;
+        }
+    }
+}
+
+// Must be internal and called `StartupHook`
+internal class StartupHook
+{
+    public static void Initialize()
+    {
+        var loadContext = new StartupAssemblyLoadContext();
+        var assembly = loadContext.LoadFromAssemblyName(new AssemblyName("WoofWare.NUnitTestRunner.StartupHookLogic"));
+        assembly.DefinedTypes.First(x => x.Name == "StartupHookLogic").GetDeclaredMethod("DoIt")!.Invoke(null, null);
+    }
+}

WoofWare.NUnitTestRunner.StartupHook/WoofWare.NUnitTestRunner.StartupHook.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\WoofWare.NUnitTestRunner.StartupHookLogic\WoofWare.NUnitTestRunner.StartupHookLogic.csproj" />
+    <ProjectReference Include="..\WoofWare.NUnitTestRunner.Lib\WoofWare.NUnitTestRunner.Lib.fsproj"/>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="StartupHook.cs"/>
+  </ItemGroup>
+
+</Project>

WoofWare.NUnitTestRunner.StartupHookLogic/StartupHookLogic.cs

@@ -0,0 +1,102 @@
+using System.Reflection;
+using Microsoft.FSharp.Collections;
+using Microsoft.FSharp.Core;
+
+namespace WoofWare.NUnitTestRunner.StartupHookLogic;
+
+public class StartupHookLogic
+{
+    private static void DoIt()
+    {
+        // Load test runner lib
+        var nunitLib = Environment.GetEnvironmentVariable("WOOFWARE_NUNIT_LIB");
+        if (string.IsNullOrEmpty(nunitLib))
+        {
+            throw new ArgumentException("WoofWare.NUnitTestRunner hook expects to run with WOOFWARE_NUNIT_LIB set to WoofWare.NUnitTestRunner.Lib.dll");
+        }
+        Assembly.LoadFrom(nunitLib);
+
+        var startTime = DateTimeOffset.Now;
+
+        // Arg parsing
+
+        var filterVar = Environment.GetEnvironmentVariable("WOOFWARE_NUNIT_FILTER");
+        static bool NoFilter(TestFixture f, SingleTestMethod g)
+        {
+            return true;
+        }
+
+        FSharpFunc<TestFixture, FSharpFunc<SingleTestMethod, bool>> filter;
+        if (string.IsNullOrEmpty(filterVar))
+        {
+            filter = FuncConvert.FromFunc<TestFixture, SingleTestMethod, bool>(NoFilter);
+        }
+        else
+        {
+            filter = FilterModule.shouldRun(FilterModule.parse(filterVar));
+        }
+
+        var assy = Assembly.GetEntryAssembly()!;
+
+        var attrs = AssemblyLevelAttributesModule.get(assy);
+
+        FSharpOption<int> levelOfParallelism;
+        var parallelismVar = Environment.GetEnvironmentVariable("WOOFWARE_NUNIT_PARALLELISM_LEVEL");
+        if (string.IsNullOrEmpty(parallelismVar))
+        {
+            levelOfParallelism = attrs.Parallelism;
+        }
+        else
+        {
+            levelOfParallelism = FSharpOption<int>.Some(Int32.Parse(parallelismVar));
+        }
+
+        var testFixtures = assy.ExportedTypes.Select(TestFixtureModule.parse);
+        using var par =
+            new ParallelQueue(levelOfParallelism, attrs.Parallelizable, FSharpOption<CancellationToken>.None);
+        var creationTime = DateTimeOffset.Now;
+
+        var timeoutVar = Environment.GetEnvironmentVariable("WOOFWARE_NUNIT_TIMEOUT_SECS");
+        TimeSpan timeout;
+        if (string.IsNullOrEmpty(timeoutVar))
+        {
+            timeout = TimeSpan.FromHours(2.0);
+        }
+        else
+        {
+            timeout = TimeSpan.FromSeconds(Int32.Parse(timeoutVar));
+        }
+
+        var normalErr = Console.Error;
+        using var contexts = TestContexts.Empty();
+        Console.SetOut(contexts.Stdout);
+        Console.SetError(contexts.Stderr);
+        var results =
+            Task.WhenAll(testFixtures.Select(x =>
+                TestFixtureModule.run(contexts, par, TestProgress.toWriter(normalErr), filter, x)));
+
+        if (!results.Wait(timeout))
+        {
+            throw new Exception($"Tests failed to terminate within timeout of {timeout}");
+        }
+
+        var sorted =
+            results.Result.SelectMany(x => x);
+        var report = BuildTrxReport.build(assy, creationTime, startTime, ListModule.OfSeq(sorted));
+
+        var trxFile = Environment.GetEnvironmentVariable("WOOFWARE_NUNIT_GENERATE_TRX");
+        if (!string.IsNullOrEmpty(trxFile))
+        {
+            var contents = TrxReportModule.toXml(report).OuterXml;
+            var trxPath = new FileInfo(trxFile);
+            trxPath.Directory!.Create();
+            File.WriteAllText(trxPath.FullName, contents);
+            normalErr.WriteLine($"Written TRX file: {trxPath.FullName}");
+        }
+
+        if (report.ResultsSummary.Outcome.Equals(TrxOutcome.Completed))
+            Environment.Exit(0);
+        else
+            Environment.Exit(1);
+    }
+}

WoofWare.NUnitTestRunner.StartupHookLogic/WoofWare.NUnitTestRunner.StartupHookLogic.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\WoofWare.NUnitTestRunner.Lib\WoofWare.NUnitTestRunner.Lib.fsproj"/>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="StartupHookLogic.cs"/>
+  </ItemGroup>
+
+</Project>

WoofWare.NUnitTestRunner.sln

@@ -8,6 +8,10 @@ Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "WoofWare.NUnitTestRunner.Li
 EndProject
 Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "WoofWare.NUnitTestRunner.Test", "WoofWare.NUnitTestRunner\WoofWare.NUnitTestRunner.Test\WoofWare.NUnitTestRunner.Test.fsproj", "{443B01B3-2A8C-45CF-96D6-1D890EEA0533}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WoofWare.NUnitTestRunner.StartupHook", "WoofWare.NUnitTestRunner.StartupHook\WoofWare.NUnitTestRunner.StartupHook.csproj", "{E2C73D96-570C-4E3C-B997-707AF8BB0E6A}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WoofWare.NUnitTestRunner.StartupHookLogic", "WoofWare.NUnitTestRunner.StartupHookLogic\WoofWare.NUnitTestRunner.StartupHookLogic.csproj", "{A70627C8-9D19-42C2-AFEB-CFBDDDCE045D}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -30,5 +34,13 @@ Global
 		{443B01B3-2A8C-45CF-96D6-1D890EEA0533}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{443B01B3-2A8C-45CF-96D6-1D890EEA0533}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{443B01B3-2A8C-45CF-96D6-1D890EEA0533}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E2C73D96-570C-4E3C-B997-707AF8BB0E6A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E2C73D96-570C-4E3C-B997-707AF8BB0E6A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E2C73D96-570C-4E3C-B997-707AF8BB0E6A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E2C73D96-570C-4E3C-B997-707AF8BB0E6A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A70627C8-9D19-42C2-AFEB-CFBDDDCE045D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A70627C8-9D19-42C2-AFEB-CFBDDDCE045D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A70627C8-9D19-42C2-AFEB-CFBDDDCE045D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A70627C8-9D19-42C2-AFEB-CFBDDDCE045D}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

WoofWare.NUnitTestRunner/Program.fs

@@ -1,42 +1,22 @@
 namespace WoofWare.NUnitTestRunner
 
 open System
+open System.Diagnostics
 open System.IO
+open System.Reflection
 open System.Threading.Tasks
 open Spectre.Console
 
-// Fix for https://github.com/Smaug123/unofficial-nunit-runner/issues/8
-// Set AppContext.BaseDirectory to where the test DLL is.
-// (This tells the DLL loader to look next to the test DLL for dependencies.)
-type SetBaseDir (testDll : FileInfo) =
-    let oldBaseDir = AppContext.BaseDirectory
-    do AppContext.SetData ("APP_CONTEXT_BASE_DIRECTORY", testDll.Directory.FullName)
-
-    interface IDisposable with
-        member _.Dispose () =
-            AppContext.SetData ("APP_CONTEXT_BASE_DIRECTORY", oldBaseDir)
-
-
 module Program =
-    let main argv =
+    // This is actually transcribed into C# in WoofWare.NUnitTestRunner.StartupHookLogic.
+    let execute argv =
         let startTime = DateTimeOffset.Now
 
-        let testDll, filter, trxPath =
-            match argv |> List.ofSeq with
-            | [ dll ] -> FileInfo dll, None, None
-            | [ dll ; "--trx" ; trxPath ] -> FileInfo dll, None, Some (FileInfo trxPath)
-            | [ dll ; "--filter" ; filter ] -> FileInfo dll, Some (Filter.parse filter), None
-            | [ dll ; "--trx" ; trxPath ; "--filter" ; filter ] ->
-                FileInfo dll, Some (Filter.parse filter), Some (FileInfo trxPath)
-            | [ dll ; "--filter" ; filter ; "--trx" ; trxPath ] ->
-                FileInfo dll, Some (Filter.parse filter), Some (FileInfo trxPath)
-            | _ ->
-                failwith
-                    "provide exactly one arg, a test DLL; then optionally `--filter <filter>` and/or `--trx <output-filename>`."
+        let args = argv |> List.ofArray |> Args.Parse
 
         let filter =
-            match filter with
-            | Some filter -> Filter.shouldRun filter
+            match args.Filter with
+            | Some (_, filter) -> Filter.shouldRun filter
             | None -> fun _ _ -> true
 
         let stderr =
@@ -46,55 +26,38 @@ module Program =
 
         let progress = Progress.spectre stderr
 
-        use _ = new SetBaseDir (testDll)
+        let runtime = DotnetRuntime.locate args.Dll
+
+        match args.Logging with
+        | LogLevel.Nothing -> ()
+        | LogLevel.Verbose ->
+            for d in runtime do
+                stderr.WriteLine $".NET runtime directory: %s{d.FullName}"
 
         use contexts = TestContexts.Empty ()
 
-        let ctx = LoadContext (testDll, DotnetRuntime.locate testDll, contexts)
-        let assy = ctx.LoadFromAssemblyPath testDll.FullName
+        let ctx = LoadContext (args.Dll, runtime, contexts)
+        let assy = ctx.LoadFromAssemblyPath args.Dll.FullName
 
-        let levelOfParallelism, par =
-            ((None, None), assy.CustomAttributes)
-            ||> Seq.fold (fun (levelPar, par) attr ->
-                match attr.AttributeType.FullName with
-                | "NUnit.Framework.LevelOfParallelismAttribute" ->
-                    let arg = attr.ConstructorArguments |> Seq.exactlyOne |> _.Value |> unbox<int>
+        let attrs = AssemblyLevelAttributes.get assy
 
-                    match levelPar with
-                    | None -> (Some arg, par)
-                    | Some existing ->
-                        failwith $"Assembly %s{assy.Location} declares parallelism %i{arg} and also %i{existing}"
-                | "NUnit.Framework.NonParallelizableAttribute" ->
-                    match levelPar with
-                    | None -> (Some 1, par)
-                    | Some existing ->
-                        failwith
-                            $"Assembly %s{assy.Location} declares non-parallelizable and also parallelism %i{existing}"
-                | "NUnit.Framework.ParallelizableAttribute" ->
-                    match par with
-                    | Some _ -> failwith "Got multiple Parallelize attributes in assembly"
-                    | None ->
-                        match attr.ConstructorArguments |> Seq.toList with
-                        | [] -> levelPar, Some (Parallelizable.Yes AssemblyParallelScope.Fixtures)
-                        | [ v ] ->
-                            match v.Value with
-                            | :? int as v ->
-                                match v with
-                                | 512 -> levelPar, Some (Parallelizable.Yes AssemblyParallelScope.Fixtures)
-                                | 256 -> levelPar, Some (Parallelizable.Yes AssemblyParallelScope.Children)
-                                | 257 ->
-                                    failwith "ParallelScope.All is invalid on assemblies; only Fixtures or Children"
-                                | 1 ->
-                                    failwith "ParallelScope.Self is invalid on assemblies; only Fixtures or Children"
-                                | v -> failwith $"Could not recognise value %i{v} of parallel scope on assembly"
-                            | v -> failwith $"Unexpectedly non-int value %O{v} of parallel scope on assembly"
-                        | _ -> failwith "unexpectedly got multiple args to Parallelizable on assembly"
-                | _ -> levelPar, par
-            )
+        let levelOfParallelism =
+            match args.LevelOfParallelism, attrs.Parallelism with
+            | None, None -> None
+            | Some taken, Some ignored ->
+                match args.Logging with
+                | LogLevel.Nothing -> ()
+                | LogLevel.Verbose ->
+                    stderr.WriteLine
+                        $"Taking parallelism %i{taken} from command line, ignoring value %i{ignored} from assembly"
+
+                Some taken
+            | Some x, None
+            | None, Some x -> Some x
 
         let testFixtures = assy.ExportedTypes |> Seq.map TestFixture.parse |> Seq.toList
 
-        use par = new ParallelQueue (levelOfParallelism, par)
+        use par = new ParallelQueue (levelOfParallelism, attrs.Parallelizable)
 
         let creationTime = DateTimeOffset.Now
 
@@ -103,240 +66,19 @@ module Program =
             |> List.map (TestFixture.run contexts par progress filter)
             |> Task.WhenAll
 
-        if not (results.Wait (TimeSpan.FromHours 2.0)) then
+        let timeout =
+            match args.Timeout with
+            | None -> TimeSpan.FromHours 2.0
+            | Some t -> t
+
+        if not (results.Wait timeout) then
             failwith "Tests failed to terminate within two hours"
 
         let results = results.Result |> Seq.concat |> List.ofSeq
 
-        let finishTime = DateTimeOffset.Now
-        let finishTimeHumanReadable = finishTime.ToString @"yyyy-MM-dd HH:mm:ss"
-        let nowMachine = finishTime.ToString @"yyyy-MM-dd_HH_mm_ss"
+        let report = BuildTrxReport.build assy creationTime startTime results
 
-        let testListId = Guid.NewGuid ()
-
-        let testDefinitions, testEntries =
-            results
-            |> List.collect (fun results -> results.IndividualTestRunMetadata)
-            |> List.map (fun (data, _) ->
-                let defn =
-                    {
-                        Name = data.TestName
-                        Storage = assy.Location.ToLowerInvariant ()
-                        Id = data.TestId
-                        Execution =
-                            {
-                                Id = data.ExecutionId
-                            }
-                        TestMethod =
-                            {
-                                CodeBase = assy.Location
-                                AdapterTypeName = Uri "executor://woofware/"
-                                ClassName = data.ClassName
-                                Name = data.TestName
-                            }
-                    }
-
-                let entry : TrxTestEntry =
-                    {
-                        TestListId = testListId
-                        ExecutionId = data.ExecutionId
-                        TestId = data.TestId
-
-                    }
-
-                defn, entry
-            )
-            |> List.unzip
-
-        let hostname = Environment.MachineName
-
-        let settings =
-            {
-                Name = "default"
-                Id = Guid.NewGuid ()
-                Deployment =
-                    {
-                        RunDeploymentRoot = $"_%s{hostname}_%s{nowMachine}"
-                    }
-            }
-
-        let testList : TrxTestListEntry =
-            {
-                Id = testListId
-                Name = "All"
-            }
-
-        let counters =
-            (TrxCounters.Zero, results)
-            // TODO: this is woefully inefficient
-            ||> List.fold (fun counters results ->
-                let counters =
-                    (counters, results.Failed)
-                    ||> List.fold (fun counters (_, _) ->
-                        // TODO: the counters can be more specific about the failure mode
-                        counters.AddFailed ()
-                    )
-
-                let counters =
-                    (counters, results.OtherFailures)
-                    ||> List.fold (fun counters _ ->
-                        // TODO: the counters can be more specific about the failure mode
-                        counters.AddFailed ()
-                    )
-
-                (counters, results.Success)
-                ||> List.fold (fun counters (_, success, _) ->
-                    match success with
-                    | TestMemberSuccess.Ok -> counters.AddPassed ()
-                    | TestMemberSuccess.Ignored _
-                    | TestMemberSuccess.Explicit _ -> counters.AddNotExecuted ()
-                    | TestMemberSuccess.Inconclusive _ -> counters.AddInconclusive ()
-                )
-            )
-
-        // TODO: I'm sure we can do better than this; there's a whole range of possible
-        // states!
-        let outcome =
-            if counters.Failed > 0u then
-                TrxOutcome.Failed
-            else
-                TrxOutcome.Completed
-
-        let resultSummary : TrxResultsSummary =
-            {
-                Outcome = outcome
-                Counters = counters
-                Output =
-                    {
-                        StdOut = None
-                        StdErr = None
-                        ErrorInfo = None
-                    }
-                RunInfos =
-                    [
-                    // TODO: capture stdout
-                    ]
-            }
-
-        let times : TrxReportTimes =
-            {
-                Creation = creationTime
-                Queuing = startTime
-                Start = startTime
-                Finish = finishTime
-
-            }
-
-        let magicGuid = Guid.Parse "13cdc9d9-ddb5-4fa4-a97d-d965ccfc6d4b"
-
-        let results =
-            results
-            |> List.collect (fun results -> results.IndividualTestRunMetadata)
-            |> List.map (fun (i, cause) ->
-                let exc =
-                    match cause with
-                    | Choice2Of3 _ -> None
-                    | Choice1Of3 (TestMemberFailure.Malformed reasons) ->
-                        {
-                            StackTrace = None
-                            Message = reasons |> String.concat "\n" |> Some
-                        }
-                        |> Some
-                    | Choice1Of3 (TestMemberFailure.Failed fail)
-                    | Choice1Of3 (TestMemberFailure.Failed fail)
-                    | Choice1Of3 (TestMemberFailure.Failed fail) ->
-                        ((None, None), fail)
-                        ||> List.fold (fun (stackTrace, message) tf ->
-                            match tf with
-                            | TestFailure.TestFailed (UserMethodFailure.Threw (_, exc))
-                            | TestFailure.SetUpFailed (UserMethodFailure.Threw (_, exc))
-                            | TestFailure.TearDownFailed (UserMethodFailure.Threw (_, exc)) ->
-                                let stackTrace =
-                                    match stackTrace with
-                                    | None -> (exc : Exception).ToString ()
-                                    | Some s -> s
-
-                                (Some stackTrace, message)
-                            | TestFailure.TestFailed (UserMethodFailure.ReturnedNonUnit (_, ret))
-                            | TestFailure.SetUpFailed (UserMethodFailure.ReturnedNonUnit (_, ret))
-                            | TestFailure.TearDownFailed (UserMethodFailure.ReturnedNonUnit (_, ret)) ->
-                                let newMessage = $"returned non-unit value %O{ret}"
-
-                                let message =
-                                    match message with
-                                    | None -> newMessage
-                                    | Some message -> $"%s{message}\n%s{newMessage}"
-
-                                (stackTrace, Some message)
-                        )
-                        |> fun (stackTrace, message) ->
-                            {
-                                StackTrace = stackTrace
-                                Message = message
-                            }
-                            |> Some
-                    | Choice3Of3 (UserMethodFailure.Threw (_, exc)) ->
-                        {
-                            StackTrace = (exc : Exception).ToString () |> Some
-                            Message = None
-                        }
-                        |> Some
-                    | Choice3Of3 (UserMethodFailure.ReturnedNonUnit (_, ret)) ->
-                        {
-                            Message = $"returned non-unit value %O{ret}" |> Some
-                            StackTrace = None
-                        }
-                        |> Some
-
-                let outcome =
-                    match cause with
-                    | Choice1Of3 _ -> TrxTestOutcome.Failed
-                    | Choice2Of3 TestMemberSuccess.Ok -> TrxTestOutcome.Passed
-                    | Choice2Of3 (TestMemberSuccess.Inconclusive _) -> TrxTestOutcome.Inconclusive
-                    | Choice2Of3 (TestMemberSuccess.Ignored _)
-                    | Choice2Of3 (TestMemberSuccess.Explicit _) -> TrxTestOutcome.NotExecuted
-                    // TODO: we can totally do better here, more fine-grained classification
-                    | Choice3Of3 _ -> TrxTestOutcome.Failed
-
-                {
-                    ExecutionId = i.ExecutionId
-                    TestId = i.TestId
-                    TestName = i.TestName
-                    ComputerName = i.ComputerName
-                    Duration = i.End - i.Start
-                    StartTime = i.Start
-                    EndTime = i.End
-                    TestType = magicGuid
-                    Outcome = outcome
-                    TestListId = testListId
-                    RelativeResultsDirectory = i.ExecutionId.ToString () // for some reason
-                    Output =
-                        match i.StdOut, i.StdErr, exc with
-                        | None, None, None -> None
-                        | stdout, stderr, exc ->
-                            Some
-                                {
-                                    TrxOutput.StdOut = stdout
-                                    StdErr = stderr
-                                    ErrorInfo = exc
-                                }
-                }
-            )
-
-        let report : TrxReport =
-            {
-                Id = Guid.NewGuid ()
-                Name = $"@%s{hostname} %s{finishTimeHumanReadable}"
-                Times = times
-                Settings = settings
-                Results = results
-                TestDefinitions = testDefinitions
-                TestEntries = testEntries
-                TestLists = [ testList ]
-                ResultsSummary = resultSummary
-            }
-
-        match trxPath with
+        match args.Trx with
         | Some trxPath ->
             let contents = TrxReport.toXml report |> fun d -> d.OuterXml
             trxPath.Directory.Create ()
@@ -344,10 +86,56 @@ module Program =
             Console.Error.WriteLine $"Written TRX file: %s{trxPath.FullName}"
         | None -> ()
 
-        match outcome with
+        match report.ResultsSummary.Outcome with
         | TrxOutcome.Completed -> 0
         | _ -> 1
 
+    let main argv =
+        let args = argv |> List.ofArray |> Args.Parse
+
+        let psi = ProcessStartInfo "dotnet"
+
+        match args.Trx with
+        | None -> ()
+        | Some trx -> psi.EnvironmentVariables.Add ("WOOFWARE_NUNIT_GENERATE_TRX", trx.FullName)
+
+        match args.LevelOfParallelism with
+        | None -> ()
+        | Some par -> psi.EnvironmentVariables.Add ("WOOFWARE_NUNIT_PARALLELISM_LEVEL", string<int> par)
+
+        match args.Filter with
+        | None -> ()
+        | Some (filter, _) -> psi.EnvironmentVariables.Add ("WOOFWARE_NUNIT_FILTER", filter)
+
+        match args.Timeout with
+        | None -> ()
+        | Some timeout ->
+            psi.EnvironmentVariables.Add ("WOOFWARE_NUNIT_TIMEOUT_SECS", string<int> (int<float> timeout.TotalSeconds))
+
+        psi.ArgumentList.Add "exec"
+        psi.ArgumentList.Add args.Dll.FullName
+
+        let us = Assembly.GetExecutingAssembly().Location |> FileInfo
+
+        let startupHook =
+            Path.Combine (us.Directory.FullName, "WoofWare.NUnitTestRunner.StartupHook.dll")
+
+        psi.EnvironmentVariables.Add ("DOTNET_STARTUP_HOOKS", startupHook)
+
+        psi.EnvironmentVariables.Add (
+            "WOOFWARE_NUNIT_LIB",
+            Path.Combine (us.Directory.FullName, "WoofWare.NUnitTestRunner.Lib.dll")
+        )
+
+        use proc = new Process ()
+        proc.StartInfo <- psi
+
+        if not (proc.Start ()) then
+            failwith "Failed to start dotnet"
+
+        proc.WaitForExit ()
+        proc.ExitCode
+
     [<EntryPoint>]
     let reallyMain argv =
         // Hack to make sure `finally`s get run.

WoofWare.NUnitTestRunner/Seq.fs

@@ -1,22 +0,0 @@
-namespace WoofWare.NUnitTestRunner
-
-[<RequireQualifiedAccess>]
-module internal Seq =
-
-    let tryMinBy (f : 'a -> 'b) (s : 'a seq) : 'a option =
-        use enum = s.GetEnumerator ()
-
-        if not (enum.MoveNext ()) then
-            None
-        else
-
-        let mutable answer = enum.Current
-        let mutable fAnswer = f enum.Current
-
-        while enum.MoveNext () do
-            let fNext = f enum.Current
-
-            if fNext < fAnswer then
-                answer <- enum.Current
-
-        Some answer

WoofWare.NUnitTestRunner/WoofWare.NUnitTestRunner.fsproj

@@ -2,7 +2,8 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
+    <RollForward>Major</RollForward>
     <PackAsTool>true</PackAsTool>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Patrick Stevens</Authors>
@@ -19,7 +20,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="Seq.fs" />
     <Compile Include="Progress.fs" />
     <Compile Include="Program.fs" />
     <None Include="..\README.md">
@@ -30,6 +30,8 @@
 
   <ItemGroup>
     <ProjectReference Include="..\WoofWare.NUnitTestRunner.Lib\WoofWare.NUnitTestRunner.Lib.fsproj" />
+    <ProjectReference Include="..\WoofWare.NUnitTestRunner.StartupHookLogic\WoofWare.NUnitTestRunner.StartupHookLogic.csproj" />
+    <ProjectReference Include="..\WoofWare.NUnitTestRunner.StartupHook\WoofWare.NUnitTestRunner.StartupHook.csproj" />
   </ItemGroup>
 
   <ItemGroup>

flake.nix

@@ -56,13 +56,20 @@
           doCheck = true;
         };
       };
-      devShell = pkgs.mkShell {
-        buildInputs = [dotnet-sdk];
-        packages = [
-          pkgs.alejandra
-          pkgs.nodePackages.markdown-link-check
-          pkgs.shellcheck
-        ];
+      devShells = {
+        default = pkgs.mkShell {
+          packages = [
+            dotnet-sdk
+            pkgs.alejandra
+            pkgs.nodePackages.markdown-link-check
+            pkgs.shellcheck
+          ];
+        };
+        net6 = pkgs.mkShell {
+          packages = [
+            pkgs.dotnetCorePackages.runtime_6_0
+          ];
+        };
       };
     });
 }

nix/deps.nix

@@ -248,22 +248,22 @@
   })
   (fetchNuGet {
     pname = "WoofWare.DotnetRuntimeLocator";
-    version = "0.1.4";
-    sha256 = "19pp4qlyf18g704ppbcsm1rhjqjpi84py18yljj9nx70331m8bpg";
+    version = "0.1.9";
+    sha256 = "14yc3ixcn58wy0v3pbj0hjfj4iv5k1ckig0dg1n7njx30510kzyj";
   })
   (fetchNuGet {
     pname = "WoofWare.Myriad.Plugins";
-    version = "2.1.44";
-    sha256 = "0rp9hpkah60gd9x0ba2izr9ff1g7yhzv5a4pkhi5fbrwf5rpqpwx";
+    version = "2.1.45";
+    sha256 = "1i9s9aq8dqnxyn01sa10dd24y9i7cgv2d0rshmrkvbvbjkcnz9vs";
   })
   (fetchNuGet {
     pname = "WoofWare.Myriad.Plugins.Attributes";
-    version = "3.1.6";
-    sha256 = "0786pr1p0nq0854mqi2cddmh185j3jihwn6azz9wiy6nxawjbrd2";
+    version = "3.1.7";
+    sha256 = "1v1wsrjh7qz2khrlbcysj50yydqc9njj09vs1jglwscjhml1wl1v";
   })
   (fetchNuGet {
     pname = "WoofWare.PrattParser";
-    version = "0.1.2";
-    sha256 = "0spypcwsbn805yrs6grjj68ccva902lhkq93mxy32rdply1xs34q";
+    version = "0.2.2";
+    sha256 = "0cgrmd1kc3k224lsjhy5npalwg6kpqd8nx78szi1yq67kyb0farq";
   })
 ]