Fix 14340 - Prompt issues between VS and fsi. (#14383)

Co-authored-by: Petr Pokorny <petr@innit.cz>
Co-authored-by: Vlad Zarytovskii <vzaritovsky@hotmail.com>

VisualFSharp.sln

@@ -193,7 +193,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "FCSBenchmarks", "FCSBenchma
 EndProject
 Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "Fsharp.ProfilingStartpointProject", "tests\benchmarks\Fsharp.ProfilingStartpointProject\Fsharp.ProfilingStartpointProject.fsproj", "{FE23BB65-276A-4E41-8CC7-F7752241DEBA}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "FSharp.Editor.Tests", "vsintegration\tests\FSharp.Editor.Tests\FSharp.Editor.Tests.fsproj", "{CBC96CC7-65AB-46EA-A82E-F6A788DABF80}"
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "FSharp.Editor.Tests", "vsintegration\tests\FSharp.Editor.Tests\FSharp.Editor.Tests.fsproj", "{CBC96CC7-65AB-46EA-A82E-F6A788DABF80}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution

src/Compiler/Interactive/fsi.fs

@@ -1127,15 +1127,38 @@ type internal FsiConsolePrompt(fsiOptions: FsiCommandLineOptions, fsiConsoleOutp
     // A prompt gets "printed ahead" at start up. Tells users to start type while initialisation completes.
     // A prompt can be skipped by "silent directives", e.g. ones sent to FSI by VS.
     let mutable dropPrompt = 0
+    let mutable showPrompt = true
+
     // NOTE: SERVER-PROMPT is not user displayed, rather it's a prefix that code elsewhere
     // uses to identify the prompt, see service\FsPkgs\FSharp.VS.FSI\fsiSessionToolWindow.fs
-    let prompt = if fsiOptions.UseServerPrompt then "SERVER-PROMPT>\n" else "> "
 
-    member _.Print()      = if dropPrompt = 0 then fsiConsoleOutput.uprintf "%s" prompt else dropPrompt <- dropPrompt - 1
+    let prompt =
+        if fsiOptions.UseServerPrompt then
+            "SERVER-PROMPT>" + Environment.NewLine
+        else
+            "> "
+
+    member _.Print() =
+        if showPrompt then
+            if dropPrompt = 0 then
+                fsiConsoleOutput.uprintf "%s" prompt
+            else
+                dropPrompt <- dropPrompt - 1
+
+    member _.PrintAhead() =
+        if showPrompt then
+            dropPrompt <- dropPrompt + 1
+            fsiConsoleOutput.uprintf "%s" prompt
 
-    member _.PrintAhead() = dropPrompt <- dropPrompt + 1; fsiConsoleOutput.uprintf "%s" prompt
+    // Can be turned off when executing blocks of code using:
+    // # silentPrompt
+    member _.ShowPrompt
+        with get () = showPrompt
+        and set (value) = showPrompt <- value
 
-    member _.SkipNext()   = dropPrompt <- dropPrompt + 1
+    member _.SkipNext() =
+        if showPrompt then
+            dropPrompt <- dropPrompt + 1
 
     member _.FsiOptions = fsiOptions
 
@@ -2772,6 +2795,15 @@ type FsiInteractionProcessor
             fsiConsolePrompt.SkipNext() (* "silent" directive *)
             istate, Completed None
 
+        | ParsedHashDirective("interactiveprompt", ParsedHashDirectiveArguments ["show" | "hide" | "skip" as showPrompt], m) ->
+            match showPrompt with
+            | "show" -> fsiConsolePrompt.ShowPrompt <- true
+            | "hide" -> fsiConsolePrompt.ShowPrompt <- false
+            | "skip" -> fsiConsolePrompt.SkipNext()
+            | _ -> error(Error((FSComp.SR.fsiInvalidDirective("prompt", String.concat " " [showPrompt])), m))
+
+            istate, Completed None
+
         | ParsedHashDirective("dbgbreak", [], _) ->
             let istate = {istate with debugBreak = true}
             istate, Completed None
@@ -3072,7 +3104,7 @@ type FsiInteractionProcessor
 
                 // After we've unblocked and got something to run we switch
                 // over to the run-thread (e.g. the GUI thread)
-                let res = istate  |> runCodeOnMainThread (fun ctok istate -> ExecuteParsedInteractionOnMainThread (ctok, diagnosticsLogger, action, istate, cancellationToken))
+                let res = istate |> runCodeOnMainThread (fun ctok istate -> ExecuteParsedInteractionOnMainThread (ctok, diagnosticsLogger, action, istate, cancellationToken))
 
                 if progress then fprintfn fsiConsoleOutput.Out "Just called runCodeOnMainThread, res = %O..." res
                 res)

src/Compiler/Service/ServiceLexing.fs

@@ -1126,6 +1126,7 @@ type FSharpLineTokenizer(lexbuf: UnicodeLexing.Lexbuf, maxLength: int option, fi
                     | true, "savedll"
                     | true, "nosavedll"
 #endif
+                    | true, "interactiveprompt"
                     | true, "silentCd"
                     | true, "q"
                     | true, "quit"

vsintegration/src/FSharp.VS.FSI/fsiSessionToolWindow.fs

@@ -534,17 +534,16 @@ type internal FsiToolWindow() as this =
             executeTextNoHistory null text
         with _ -> ()
 
-    let executeInteraction dbgBreak dir (filename: string) topLine text =
-        // Preserving previous functionality, including the #directives...
-        let interaction =
-            "\n"
-          + (sprintf "# silentCd @\"%s\" ;; " dir) + "\n"
-          + (if dbgBreak then "# dbgbreak\n" else "")
-          + (sprintf "# %d @\"%s\" " topLine filename) + "\n"
-          + text + "\n"
-          + "# 1 \"stdin\"" + "\n" (* stdin line number reset code *)
-          + ";;" + "\n"
-
+    let executeInteraction dbgBreak dir filename topLine (text:string) =
+        let interaction = $"""
+#interactiveprompt "hide"
+#silentCd @"{dir}";;
+{if dbgBreak then "#dbgbreak" else ""}
+#{topLine} @"{filename}"
+{text.ToString()}
+#1 "stdin"
+#interactiveprompt "show";;
+"""
         executeTextNoHistory filename interaction
 
     let sendSelectionToFSI action =
@@ -555,8 +554,8 @@ type internal FsiToolWindow() as this =
             | DebugSelection -> true, false
 
         try
-            let dte = provider.GetService(typeof<DTE>) :?> DTE        
-            let activeD = dte.ActiveDocument            
+            let dte = provider.GetService(typeof<DTE>) :?> DTE
+            let activeD = dte.ActiveDocument
             match activeD.Selection with
             | :? TextSelection as selection when selectLine || selection.Text = "" ->
                 selection.SelectLine()