separate fsi tooltask for tests

Author: majocha

FSharpTests.Directory.Build.targets

@@ -1,13 +1,14 @@
 <Project>
 
-  <UsingTask TaskName="Fsi" AssemblyFile="$(FSharpBuildAssemblyFile)" />
+  <UsingTask TaskName="FsiTestTask" AssemblyFile="$(FSharpBuildAssemblyFile)" />
 
     <Target
         Name="RunFSharpScript"
         Returns=""
         DependsOnTargets="$(CoreCompileDependsOn)"
     >
-        <Fsi  Condition=" '%(_CoreCompileResourceInputs.WithCulture)' != 'true' "
+      <FsiTestTask
+              Condition=" '%(_CoreCompileResourceInputs.WithCulture)' != 'true' "
               CodePage="$(CodePage)"
               DefineConstants="$(DefineConstants)"
               DisabledWarnings="$(NoWarn)"
@@ -34,7 +35,7 @@
               WarningsAsErrors="$(WarningsAsErrors)">
           <Output TaskParameter="CommandLineArgs" ItemName="FsiCommandLineArgs" />
           <Output TaskParameter="TextOutput" ItemName="FsiTextOutput" />
-        </Fsi>
+        </FsiTestTask>
 
       <ItemGroup>
           <_CoreCompileResourceInputs Remove="@(_CoreCompileResourceInputs)" />

src/FSharp.Build/FSharp.Build.fsproj

@@ -38,6 +38,7 @@
     <Compile Include="FSharpCommandLineBuilder.fs" />
     <Compile Include="Fsc.fs" />
     <Compile Include="Fsi.fs" />
+    <Compile Include="FsiTestTask.fs" />
     <Compile Include="FSharpEmbedResourceText.fs" />
     <Compile Include="FSharpEmbedResXSource.fs" />
     <Compile Include="WriteCodeFragment.fs" />

src/FSharp.Build/Fsi.fs

@@ -161,12 +161,6 @@ type public Fsi() as this =
 
         builder
 
-    let outputWriter = new StringWriter()
-
-    override _.LogEventsFromTextOutput(line, msgImportance) =
-        outputWriter.WriteLine(line)
-        base.LogEventsFromTextOutput(line, msgImportance)
-
     // --codepage <int>: Specify the codepage to use when opening source files
     member _.CodePage
         with get () = codePage
@@ -289,9 +283,6 @@ type public Fsi() as this =
         with get () = List.toArray commandLineArgs
         and set value = commandLineArgs <- List.ofArray value
 
-    [<Output>]
-    member _.TextOutput = outputWriter.ToString()
-
     // ToolTask methods
     override _.ToolName = "fsi.exe"
 

src/FSharp.Build/FsiTestTask.fs

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace FSharp.Build.Tests
+
+open System.IO
+open Microsoft.Build.Framework
+
+/// MsBuild tool task for capturing stdout from test scripts.
+type FsiTestTask() =
+    inherit FSharp.Build.Fsi()
+
+    // Just to keep a reasonable amount of test scipt output.
+    let outputWriter = new StringWriter()
+
+    override _.LogEventsFromTextOutput(line, msgImportance) =
+        outputWriter.WriteLine(line)
+        base.LogEventsFromTextOutput(line, msgImportance)
+
+    [<Output>]
+    member _.TextOutput = outputWriter.ToString()