Added null test for AddBoundValue. Making FsiTests single-threaded (#9184)

Author: TIHan

src/fsharp/fsi/fsi.fs

@@ -2922,15 +2922,19 @@ type FsiEvaluationSession (fsi: FsiEvaluationSessionHostConfig, argv:string[], i
     member __.TryFindBoundValue(name: string) =
         fsiDynamicCompiler.TryFindBoundValue(fsiInteractionProcessor.CurrentState, name)
 
-    member __.AddBoundValue(name: string, reflectionValue: obj) =
+    member __.AddBoundValue(name: string, value: obj) =
+        match value with
+        | null -> nullArg "value"
+        | _ -> ()
+
         // Explanation: When the user of the FsiInteractiveSession object calls this method, the 
         // code is parsed, checked and evaluated on the calling thread. This means EvalExpression
         // is not safe to call concurrently.
         let ctok = AssumeCompilationThreadWithoutEvidence()
 
         let errorOptions = TcConfig.Create(tcConfigB, validate = false).errorSeverityOptions
         let errorLogger = CompilationErrorLogger("AddBoundValue", errorOptions)
-        fsiInteractionProcessor.AddBoundValue(ctok, errorLogger, name, reflectionValue)
+        fsiInteractionProcessor.AddBoundValue(ctok, errorLogger, name, value)
         let errs = errorLogger.GetErrors()
         ErrorHelpers.CreateErrorInfos (errorOptions, true, "input.fsx", errs, true)
 

src/fsharp/fsi/fsi.fsi

@@ -269,7 +269,7 @@ type FsiEvaluationSession =
     /// Creates a root-level value with the given name and .NET object.
     /// If the .NET object contains types from assemblies that are not referenced in the interactive session, it will try to implicitly resolve them by default configuration.
     /// Name must be a valid identifier.
-    member AddBoundValue : name: string * reflectionValue: obj -> FSharpErrorInfo[]
+    member AddBoundValue : name: string * value: obj -> FSharpErrorInfo[]
 
     /// Load the dummy interaction, load the initial files, and,
     /// if interacting, start the background thread to read the standard input.

tests/FSharp.Compiler.UnitTests/FsiTests.fs

@@ -1,5 +1,7 @@
-module FSharp.Compiler.UnitTests.FsiTests
+[<NUnit.Framework.SingleThreaded>]
+module FSharp.Compiler.UnitTests.FsiTests
 
+open System
 open System.IO
 open FSharp.Compiler.Interactive.Shell
 open NUnit.Framework
@@ -404,6 +406,12 @@ let ``Creation of a bound value fails if the name contains dots`` () =
     Assert.AreEqual(FSharpErrorSeverity.Error, error.Severity)
     Assert.AreEqual("Identifier expected", error.Message)
 
+[<Test>]
+let ``Creation of a bound value throws if the value passed is null`` () =
+    use fsiSession = createFsiSession ()
+
+    Assert.Throws<ArgumentNullException>(fun () -> fsiSession.AddBoundValue("x", null) |> ignore) |> ignore
+
 [<Test>]
 let ``Creation of a bound value succeeds if the value contains types from assemblies that are not referenced in the session, due to implicit resolution`` () =
     use fsiSession = createFsiSession ()