Fix ServiceAssemblyContent for symbols from modules with auto added "Module" suffix (#4102)

* fix ServiceAssemblyContent for symbols from modules with auto added "Module" suffix

* add tests

* correct a test

* improve the tests

src/fsharp/service/ServiceAssemblyContent.fs

@@ -157,10 +157,10 @@ type Parent =
                 else ident)
 
         let removeModuleSuffix (idents: Idents) =
-            if entity.IsFSharpModule && idents.Length > 0 && Symbol.hasModuleSuffixAttribute entity then
+            if entity.IsFSharpModule && idents.Length > 0 then
                 let lastIdent = idents.[idents.Length - 1]
-                if lastIdent.EndsWith "Module" then
-                    idents |> Array.replace (idents.Length - 1) (lastIdent.Substring(0, lastIdent.Length - 6))
+                if lastIdent <> entity.DisplayName then
+                    idents |> Array.replace (idents.Length - 1) entity.DisplayName
                 else idents
             else idents
 
@@ -275,7 +275,7 @@ module AssemblyContentProvider =
                             | false, _ -> None 
 
                           WithModuleSuffix = 
-                            if entity.IsFSharpModule && Symbol.hasModuleSuffixAttribute entity then 
+                            if entity.IsFSharpModule && (Symbol.hasModuleSuffixAttribute entity || entity.CompiledName <> entity.DisplayName) then 
                                 currentEntity |> Option.map (fun e -> e.CleanedIdents) 
                             else parent.WithModuleSuffix
 

tests/service/AssemblyContentProviderTests.fs

+#if INTERACTIVE
+#r "../../Debug/fcs/net45/FSharp.Compiler.Service.dll" // note, run 'build fcs debug' to generate this, this DLL has a public API so can be used from F# Interactive
+#r "../../packages/NUnit.3.5.0/lib/net45/nunit.framework.dll"
+#load "FsUnit.fs"
+#load "Common.fs"
+#else
+module Tests.Service.AssemblyContentProviderTests
+#endif
+
+open System
+open System.IO
+open System.Text
+open NUnit.Framework
+open Microsoft.FSharp.Compiler.SourceCodeServices
+
+let private filePath = "C:\\test.fs"
+
+let private projectOptions : FSharpProjectOptions = 
+    { ProjectFileName = "C:\\test.fsproj"
+      SourceFiles =  [| filePath |]
+      ReferencedProjects = [| |]
+      OtherOptions = [| |]
+      IsIncompleteTypeCheckEnvironment = true
+      UseScriptResolutionRules = false
+      LoadTime = DateTime.MaxValue
+      OriginalLoadReferences = []
+      UnresolvedReferences = None
+      ExtraProjectInfo = None
+      Stamp = None }
+
+let private checker = FSharpChecker.Create()
+
+let (=>) (source: string) (expected: string list) =
+    let lines =
+        use reader = new StringReader(source)
+        [| let line = ref (reader.ReadLine())
+           while not (isNull !line) do
+               yield !line
+               line := reader.ReadLine()
+           if source.EndsWith "\n" then
+               // last trailing space not returned
+               // http://stackoverflow.com/questions/19365404/stringreader-omits-trailing-linebreak
+               yield "" |]
+
+    let _, checkFileAnswer = checker.ParseAndCheckFileInProject(filePath, 0, source, projectOptions) |> Async.RunSynchronously
+    
+    let checkFileResults =
+        match checkFileAnswer with
+        | FSharpCheckFileAnswer.Aborted -> failwithf "ParseAndCheckFileInProject aborted"
+        | FSharpCheckFileAnswer.Succeeded(checkFileResults) -> checkFileResults
+
+    let actual = 
+        AssemblyContentProvider.getAssemblySignatureContent AssemblyContentType.Full checkFileResults.PartialAssemblySignature
+        |> List.map (fun x -> x.CleanedIdents |> String.concat ".") 
+        |> List.sort
+
+    let expected = List.sort expected
+
+    if actual <> expected then failwithf "\n\nExpected\n\n%A\n\nbut was\n\n%A" expected actual
+
+[<Test>]
+let ``implicitly added Module suffix is removed``() =
+    """
+type MyType = { F: int }
+
+module MyType =
+    let func123 x = x
+"""
+    => ["Test"
+        "Test.MyType"
+        "Test.MyType"
+        "Test.MyType.func123"]
+        
+[<Test>]
+let ``Module suffix added by an xplicitly applied MuduleSuffix attribute is removed``() =
+    """
+[<CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
+module MyType =
+    let func123 x = x
+"""
+    => [ "Test"
+         "Test.MyType"
+         "Test.MyType.func123" ]
+
+

vsintegration/tests/unittests/VisualFSharp.UnitTests.fsproj

@@ -94,6 +94,9 @@
     <Compile Include="..\..\..\tests\service\StructureTests.fs">
       <Link>StructureTests.fs</Link>
     </Compile>
+    <Compile Include="..\..\..\tests\service\AssemblyContentProviderTests.fs">
+      <Link>AssemblyContentProviderTests.fs</Link>
+    </Compile>
     <Compile Include="UnusedOpensTests.fs">
       <Link>ServiceAnalysis\UnusedOpensTests.fs</Link>
     </Compile>