Day 1 in F#

AdventOfCode2023.FSharp/Test/Test.fsproj

@@ -8,6 +8,7 @@
     </PropertyGroup>
 
     <ItemGroup>
+        <Compile Include="TestDay1.fs" />
         <Compile Include="TestDay3.fs" />
     </ItemGroup>
 

AdventOfCode2023.FSharp/Test/TestDay1.fs

@@ -0,0 +1,56 @@
+namespace AdventOfCode2023.Test
+
+open AdventOfCode2023
+open NUnit.Framework
+open FsUnitTyped
+open System.IO
+
+[<TestFixture>]
+module TestDay1 =
+
+    let sample1 =
+        """1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet
+"""
+
+    [<Test>]
+    let part1Sample () =
+        sample1 |> Day1.part1 |> shouldEqual 142
+
+    let sample2 =
+        """two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen
+"""
+
+    [<Test>]
+    let part2Sample () =
+        sample2 |> Day1.part2 |> shouldEqual 281
+
+    [<Test>]
+    let part1Actual () =
+        let s =
+            try
+                File.ReadAllText (Path.Combine (__SOURCE_DIRECTORY__, "../../inputs/day1.txt"))
+            with :? FileNotFoundException ->
+                Assert.Inconclusive ()
+                failwith "unreachable"
+
+        Day1.part1 s |> shouldEqual 54304
+
+    [<Test>]
+    let part2Actual () =
+        let s =
+            try
+                File.ReadAllText (Path.Combine (__SOURCE_DIRECTORY__, "../../inputs/day1.txt"))
+            with :? FileNotFoundException ->
+                Assert.Inconclusive ()
+                failwith "unreachable"
+
+        Day1.part2 s |> shouldEqual 54418