Fix typo resulting in failed renders (#24)

WoofWare.Expect.Test/TestDot.fs

@@ -61,6 +61,7 @@ module TestDot =
 
         let mutable started = false
         let mutable waited = false
+        let mutable exitCodeObserved = false
         let mutable disposed = false
 
         let expected =
@@ -84,7 +85,7 @@ module TestDot =
                 member _.Create exe args =
                     exe |> shouldEqual "graph-easy"
 
-                    args.StartsWith ("--as=boxarg --from=dot ", StringComparison.Ordinal)
+                    args.StartsWith ("--as=boxart --from=dot ", StringComparison.Ordinal)
                     |> shouldEqual true
 
                     { new IDisposable with
@@ -93,6 +94,10 @@ module TestDot =
 
                 member _.WaitForExit p = waited <- true
                 member _.ReadStandardOutput _ = expected
+
+                member _.ExitCode _ =
+                    exitCodeObserved <- true
+                    0
             }
 
         Dot.render' pr (toFs fs) "graph-easy" contents
@@ -101,4 +106,5 @@ module TestDot =
 
         started |> shouldEqual true
         waited |> shouldEqual true
+        exitCodeObserved |> shouldEqual true
         disposed |> shouldEqual true

WoofWare.Expect/Dot.fs

@@ -17,6 +17,8 @@ module Dot =
         abstract WaitForExit : 'Process -> unit
         /// Equivalent to Process.StandardOutput.ReadToEnd
         abstract ReadStandardOutput : 'Process -> string
+        /// Equivalent to Process.ExitCode
+        abstract ExitCode : 'Process -> int
 
     /// The real Process interface, in a form that can be passed to `render'`.
     let process' =
@@ -32,6 +34,7 @@ module Dot =
             member _.Start p = p.Start ()
             member _.WaitForExit p = p.WaitForExit ()
             member _.ReadStandardOutput p = p.StandardOutput.ReadToEnd ()
+            member _.ExitCode p = p.ExitCode
         }
 
     /// A mock for System.IO
@@ -66,11 +69,17 @@ module Dot =
         try
             fs.WriteFile tempFile dotFileContents
 
-            use p = pr.Create graphEasyExecutable ("--as=boxarg --from=dot " + tempFile)
+            use p = pr.Create graphEasyExecutable ("--as=boxart --from=dot " + tempFile)
             pr.Start p |> ignore<bool>
             pr.WaitForExit p
 
-            "\n" + pr.ReadStandardOutput p
+            let stdout = pr.ReadStandardOutput p
+            let exitCode = pr.ExitCode p
+
+            if exitCode <> 0 then
+                failwithf "failed to run; exit code: %i. stdout:\n%s" exitCode stdout
+
+            "\n" + stdout
         finally
             try
                 fs.DeleteFile tempFile

WoofWare.Expect/SurfaceBaseline.txt

@@ -55,8 +55,9 @@ WoofWare.Expect.Dot+IFileSystem - interface with 3 member(s)
 WoofWare.Expect.Dot+IFileSystem.DeleteFile [method]: string -> unit
 WoofWare.Expect.Dot+IFileSystem.GetTempFileName [method]: unit -> string
 WoofWare.Expect.Dot+IFileSystem.WriteFile [method]: string -> string -> unit
-WoofWare.Expect.Dot+IProcess`1 - interface with 4 member(s)
+WoofWare.Expect.Dot+IProcess`1 - interface with 5 member(s)
 WoofWare.Expect.Dot+IProcess`1.Create [method]: string -> string -> #(IDisposable)
+WoofWare.Expect.Dot+IProcess`1.ExitCode [method]: #(IDisposable) -> int
 WoofWare.Expect.Dot+IProcess`1.ReadStandardOutput [method]: #(IDisposable) -> string
 WoofWare.Expect.Dot+IProcess`1.Start [method]: #(IDisposable) -> bool
 WoofWare.Expect.Dot+IProcess`1.WaitForExit [method]: #(IDisposable) -> unit