Making inline type hints less intrusive

vsintegration/src/FSharp.Editor/Hints/InlineTypeHints.fs

@@ -30,11 +30,20 @@ module InlineTypeHints =
             Parts = getHintParts symbol symbolUse
         }
 
+    let private isSolved (symbol: FSharpMemberOrFunctionOrValue) = 
+        if symbol.GenericParameters.Count > 0
+        then symbol.GenericParameters |> Seq.forall (fun p -> p.IsSolveAtCompileTime)
+
+        elif symbol.FullType.IsGenericParameter 
+        then symbol.FullType.GenericParameter.DisplayNameCore <> "?"
+
+        else true
+
     let isValidForHint 
         (parseFileResults: FSharpParseFileResults) 
         (symbol: FSharpMemberOrFunctionOrValue)
         (symbolUse: FSharpSymbolUse) =
-        
+
         let isNotAnnotatedManually = 
             not (parseFileResults.IsTypeAnnotationGivenAtPosition symbolUse.Range.Start)
 
@@ -46,6 +55,7 @@ module InlineTypeHints =
             not symbol.IsConstructorThisValue
 
         symbol.IsValue // we'll be adding other stuff gradually here
+        && isSolved symbol
         && isNotAnnotatedManually
         && isNotAfterDot
         && isNotTypeAlias

vsintegration/tests/FSharp.Editor.Tests/Hints/InlineTypeHintTests.fs

@@ -183,3 +183,67 @@ let zip4 (l1: 'a list) (l2: 'b list) (l3: 'c list) (l4: 'd list) =
         let actual = getTypeHints document
 
         CollectionAssert.AreEquivalent(expected, actual)
+
+    [<Test>]
+    let ``Hints are not shown for unfinished expressions`` () =
+        let code =
+            """
+let x
+"""
+        let document = getFsDocument code
+
+        let result = getTypeHints document
+
+        Assert.IsEmpty(result)
+
+    [<Test>]
+    let ``Hints are not shown for unsolved types in _for_ expressions in collections`` () = 
+        let code =
+            """
+let _ = [ for x ]
+"""
+        let document = getFsDocument code
+
+        let result = getTypeHints document
+
+        Assert.IsEmpty(result)
+
+    [<Test>]
+    let ``Hints are not shown for unsolved types in _for_ expressions within computational expressions`` () = 
+        let code =
+            """
+do task {
+    for x
+
+    do! Task.Delay 0
+    }
+"""
+        let document = getFsDocument code
+
+        let result = getTypeHints document
+
+        Assert.IsEmpty(result)
+
+    [<Test>]
+    let ``Hints are shown for IWSAM`` () =
+        let code =
+            """
+type IAddition<'T when 'T :> IAddition<'T>> =
+    static abstract op_Addition: 'T * 'T -> 'T
+
+type Number<'T when IAddition<'T>>(value: 'T) =
+    member _.Value with get() = value
+    interface IAddition<Number<'T>> with
+        static member op_Addition(a, b) = Number(a.Value + b.Value)
+"""
+        let document = getFsDocument code
+
+        let expected =
+            [
+                { Content = ": Number<'T>"; Location = (7, 36) }
+                { Content = ": Number<'T>"; Location = (7, 39) }
+            ]
+
+        let actual = getTypeHints document
+
+        CollectionAssert.AreEquivalent(expected, actual)