move console input/output redirect out of script helper (#8108)

* move console input/output redirect out of script helper

* address review feedback

* string splitting is hard

Author: brettfo

src/fsharp/FSharp.Compiler.Private.Scripting/FSharp.Compiler.Private.Scripting.fsproj

@@ -9,13 +9,12 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="TextHelpers.fs" />
     <Compile Include="FSharpScript.fs" />
   </ItemGroup>
 
   <ItemGroup>
-    <NuspecProperty Include="FSharpCoreVersion=$(FSCorePackageVersion)-$(VersionSuffix)"/>
-    <NuspecProperty Include="TargetFramework=$(TargetFramework)"/>
+    <NuspecProperty Include="FSharpCoreVersion=$(FSCorePackageVersion)-$(VersionSuffix)" />
+    <NuspecProperty Include="TargetFramework=$(TargetFramework)" />
   </ItemGroup>
 
   <ItemGroup>

src/fsharp/FSharp.Compiler.Private.Scripting/FSharpScript.fs

@@ -7,49 +7,22 @@ open System.Threading
 open FSharp.Compiler
 open FSharp.Compiler.Interactive.Shell
 
-type FSharpScript(?captureInput: bool, ?captureOutput: bool, ?additionalArgs: string[]) as this =
-    let outputProduced = Event<string>()
-    let errorProduced = Event<string>()
+type FSharpScript(?additionalArgs: string[]) =
 
-    // handle stdin/stdout
-    let stdin = new CapturedTextReader()
-    let stdout = new EventedTextWriter()
-    let stderr = new EventedTextWriter()
-    do stdout.LineWritten.Add outputProduced.Trigger
-    do stderr.LineWritten.Add errorProduced.Trigger
-    let captureInput = defaultArg captureInput false
-    let captureOutput = defaultArg captureOutput false
     let additionalArgs = defaultArg additionalArgs [||]
-    let savedInput = Console.In
-    let savedOutput = Console.Out
-    let savedError = Console.Error
-    do (fun () ->
-        if captureInput then
-            Console.SetIn(stdin)
-        if captureOutput then
-            Console.SetOut(stdout)
-            Console.SetError(stderr)
-        ())()
-
     let config = FsiEvaluationSession.GetDefaultConfiguration()
     let computedProfile =
         // If we are being executed on the desktop framework (we can tell because the assembly containing int is mscorlib) then profile must be mscorlib otherwise use netcore
         if typeof<int>.Assembly.GetName().Name = "mscorlib" then "mscorlib"
         else "netcore"
-    let baseArgs = [| this.GetType().Assembly.Location; "--noninteractive"; "--targetprofile:" + computedProfile; "--quiet" |]
+    let baseArgs = [| typeof<FSharpScript>.Assembly.Location; "--noninteractive"; "--targetprofile:" + computedProfile; "--quiet" |]
     let argv = Array.append baseArgs additionalArgs
     let fsi = FsiEvaluationSession.Create (config, argv, stdin, stdout, stderr, collectible=true)
 
     member __.AssemblyReferenceAdded = fsi.AssemblyReferenceAdded
 
     member __.ValueBound = fsi.ValueBound
 
-    member __.ProvideInput = stdin.ProvideInput
-
-    member __.OutputProduced = outputProduced.Publish
-
-    member __.ErrorProduced = errorProduced.Publish
-
     member __.Fsi = fsi
 
     member __.Eval(code: string, ?cancellationToken: CancellationToken) =
@@ -75,12 +48,4 @@ type FSharpScript(?captureInput: bool, ?captureOutput: bool, ?additionalArgs: st
 
     interface IDisposable with
         member __.Dispose() =
-            if captureInput then
-                Console.SetIn(savedInput)
-            if captureOutput then
-                Console.SetOut(savedOutput)
-                Console.SetError(savedError)
-            stdin.Dispose()
-            stdout.Dispose()
-            stderr.Dispose()
             (fsi :> IDisposable).Dispose()

src/fsharp/FSharp.Compiler.Private.Scripting/TextHelpers.fs

@@ -0,0 +1,64 @@
+namespace FSharp.Compiler.Scripting.UnitTests
+
+open System
+open System.Collections.Generic
+open System.IO
+open System.Text
+
+type internal CapturedTextReader() =
+    inherit TextReader()
+    let queue = Queue<char>()
+    member _.ProvideInput(text: string) =
+        for c in text.ToCharArray() do
+            queue.Enqueue(c)
+    override _.Peek() =
+        if queue.Count > 0 then queue.Peek() |> int else -1
+    override _.Read() =
+        if queue.Count > 0 then queue.Dequeue() |> int else -1
+
+type internal RedirectConsoleInput() =
+    let oldStdIn = Console.In
+    let newStdIn = new CapturedTextReader()
+    do Console.SetIn(newStdIn)
+    member _.ProvideInput(text: string) =
+        newStdIn.ProvideInput(text)
+    interface IDisposable with
+        member __.Dispose() =
+            Console.SetIn(oldStdIn)
+            newStdIn.Dispose()
+
+type internal EventedTextWriter() =
+    inherit TextWriter()
+    let sb = StringBuilder()
+    let lineWritten = Event<string>()
+    member _.LineWritten = lineWritten.Publish
+    override _.Encoding = Encoding.UTF8
+    override _.Write(c: char) =
+        if c = '\n' then
+            let line =
+                let v = sb.ToString()
+                if v.EndsWith("\r") then v.Substring(0, v.Length - 1)
+                else v
+            sb.Clear() |> ignore
+            lineWritten.Trigger(line)
+        else sb.Append(c) |> ignore
+
+type internal RedirectConsoleOutput() =
+    let outputProduced = Event<string>()
+    let errorProduced = Event<string>()
+    let oldStdOut = Console.Out
+    let oldStdErr = Console.Error
+    let newStdOut = new EventedTextWriter()
+    let newStdErr = new EventedTextWriter()
+    do newStdOut.LineWritten.Add outputProduced.Trigger
+    do newStdErr.LineWritten.Add errorProduced.Trigger
+    do Console.SetOut(newStdOut)
+    do Console.SetError(newStdErr)
+    member _.OutputProduced = outputProduced.Publish
+    member _.ErrorProduced = errorProduced.Publish
+    interface IDisposable with
+        member __.Dispose() =
+            Console.SetOut(oldStdOut)
+            Console.SetError(oldStdErr)
+            newStdOut.Dispose()
+            newStdErr.Dispose()

tests/FSharp.Compiler.Private.Scripting.UnitTests/ConsoleHelpers.fs

@@ -11,6 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <Compile Include="ConsoleHelpers.fs" />
     <Compile Include="TestHelpers.fs" />
     <Compile Include="FSharpScriptTests.fs" />
     <Compile Include="CompletionTests.fs" />

tests/FSharp.Compiler.Private.Scripting.UnitTests/FSharp.Compiler.Private.Scripting.UnitTests.fsproj

@@ -32,20 +32,22 @@ type InteractiveTests() =
 
     [<Test>]
     member __.``Capture console input``() =
-        use script = new FSharpScript(captureInput=true)
-        script.ProvideInput "stdin:1234\r\n"
+        use input = new RedirectConsoleInput()
+        use script = new FSharpScript()
+        input.ProvideInput "stdin:1234\r\n"
         let opt = script.Eval("System.Console.ReadLine()") |> getValue
         let value = opt.Value
         Assert.AreEqual(typeof<string>, value.ReflectionType)
         Assert.AreEqual("stdin:1234", value.ReflectionValue)
 
     [<Test>]
     member __.``Capture console output/error``() =
-        use script = new FSharpScript(captureOutput=true)
+        use output = new RedirectConsoleOutput()
+        use script = new FSharpScript()
         use sawOutputSentinel = new ManualResetEvent(false)
         use sawErrorSentinel = new ManualResetEvent(false)
-        script.OutputProduced.Add (fun line -> if line = "stdout:1234" then sawOutputSentinel.Set() |> ignore)
-        script.ErrorProduced.Add (fun line -> if line = "stderr:5678" then sawErrorSentinel.Set() |> ignore)
+        output.OutputProduced.Add (fun line -> if line = "stdout:1234" then sawOutputSentinel.Set() |> ignore)
+        output.ErrorProduced.Add (fun line -> if line = "stderr:5678" then sawErrorSentinel.Set() |> ignore)
         script.Eval("printfn \"stdout:1234\"; eprintfn \"stderr:5678\"") |> ignoreValue
         Assert.True(sawOutputSentinel.WaitOne(TimeSpan.FromSeconds(5.0)), "Expected to see output sentinel value written")
         Assert.True(sawErrorSentinel.WaitOne(TimeSpan.FromSeconds(5.0)), "Expected to see error sentinel value written")