Specializing Operators.op_UnaryPlus for witness info (#9769)

* Initial work to fix op_UnaryPlus witness info

* Added UnaryPlusDynamic

* update surface area

* Only enable type provider test on net472

* Removing UnaryPlusDynamic

* fixing build

* fix comment

* Update prim-types.fs

Author: TIHan

src/fsharp/TcGlobals.fs

@@ -1601,6 +1601,11 @@ type public TcGlobals(compilingFslib: bool, ilg:ILGlobals, fslibCcu: CcuThunk, d
         Some (g.array_set_info, [ety], argExprs)
     | "get_Item", [sty; _; _], _, [_; _] when isStringTy g sty -> 
         Some (g.getstring_info, [], argExprs)
+    | "op_UnaryPlus", [aty], _, [_] ->
+        // Call Operators.id
+        let info = makeOtherIntrinsicValRef (fslib_MFOperators_nleref, "id", None, None, [vara], ([[varaTy]], varaTy))
+        let tyargs = [aty]
+        Some (info, tyargs, argExprs)
     | _ ->
         None
 

tests/fsharp/Compiler/Language/CodeQuotationTests.fs

@@ -0,0 +1,43 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace FSharp.Compiler.UnitTests
+
+open NUnit.Framework
+open FSharp.Test.Utilities.Compiler
+open FSharp.Quotations.Patterns
+
+[<TestFixture>]
+module CodeQuotationsTests =
+
+    [<Test>]
+    let ``Quotation on op_UnaryPlus(~+) compiles and runs`` () =
+        Fsx """
+open FSharp.Linq.RuntimeHelpers
+open FSharp.Quotations.Patterns
+open FSharp.Quotations.DerivedPatterns
+
+let eval q = LeafExpressionConverter.EvaluateQuotation q
+
+let inline f x = <@ (~+) x @>
+let x = <@ f 1 @>
+let y : unit =
+    match f 1 with
+    | Call(_, methInfo, _) when methInfo.Name = "op_UnaryPlus" ->
+        ()
+    | e ->
+        failwithf "did not expect expression for 'y': %A" e
+let z : unit =
+    match f 5 with
+    | (CallWithWitnesses(_, methInfo, methInfoW, _, _) as e) when methInfo.Name = "op_UnaryPlus" && methInfoW.Name = "op_UnaryPlus$W" ->
+        if ((eval e) :?> int) = 5 then
+            ()
+        else
+            failwith "did not expect evaluation false"
+    | e ->
+        failwithf "did not expect expression for 'z': %A" e
+        """
+        |> asExe
+        |> withOptions ["--langversion:preview"]
+        |> compileAndRun
+        
+

tests/fsharp/Compiler/Language/WitnessTests.fs

@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace FSharp.Compiler.UnitTests
+
+open NUnit.Framework
+open FSharp.Test.Utilities.Compiler
+open FSharp.Tests
+
+#if !NETCOREAPP
+
+[<TestFixture>]
+module WitnessTests =
+
+    [<Test>]
+    let ``Witness expressions are created as a result of compiling the type provider tests`` () =
+        let dir = Core.getTestsDirectory "typeProviders/helloWorld"
+        Fsx (sprintf """
+#load @"%s"
+        """ (dir ++ "provider.fsx"))
+        |> asExe
+        |> ignoreWarnings
+        |> withOptions ["--langversion:preview"]
+        |> compile
+        |> shouldSucceed
+        |> ignore
+#endif
+        
+

tests/fsharp/FSharpSuite.Tests.fsproj

@@ -41,6 +41,8 @@
     <Compile Include="Compiler\Warnings\ExperimentalAttributeTests.fs" />
     <Compile Include="Compiler\Warnings\PatternMatchingWarningTests.fs" />
     <Compile Include="Compiler\SourceTextTests.fs" />
+    <Compile Include="Compiler\Language\WitnessTests.fs" />
+    <Compile Include="Compiler\Language\CodeQuotationTests.fs" />
     <Compile Include="Compiler\Language\CompilerDirectiveTests.fs" />
     <Compile Include="Compiler\Language\DefaultInterfaceMemberTests.fs" />
     <Compile Include="Compiler\Language\OptionalInteropTests.fs" />