Extra tests for type hints (#14552)

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

@@ -147,7 +147,7 @@ type Song() as x =
         Assert.IsEmpty(result)
 
     [<Test>]
-    let ``Hints are shown for lambdas`` () =
+    let ``Hints are shown within lambdas`` () =
         let code =
             """
 let iamboring() =
@@ -162,7 +162,7 @@ let iamboring() =
         Assert.AreEqual(expected, actual)
 
     [<Test>]
-    let ``Hints are shown for lambdas with tuples`` () =
+    let ``Hints are shown within lambdas with tuples`` () =
         let code =
             """
 let zip4 (l1: 'a list) (l2: 'b list) (l3: 'c list) (l4: 'd list) =
@@ -184,6 +184,19 @@ let zip4 (l1: 'a list) (l2: 'b list) (l3: 'c list) (l4: 'd list) =
 
         CollectionAssert.AreEquivalent(expected, actual)
 
+    [<Test>]
+    let ``Hints are not shown for lambda return types`` () =
+        let code =
+            """
+let func = fun () -> 3
+"""
+
+        let document = getFsDocument code
+
+        let result = getTypeHints document
+
+        Assert.IsEmpty(result)
+
     [<Test>]
     let ``Hints are not shown for unfinished expressions`` () =
         let code =
@@ -248,7 +261,6 @@ type Number<'T when IAddition<'T>>(value: 'T) =
 
         CollectionAssert.AreEquivalent(expected, actual)
 
-
     [<Test>]
     let ``Hints are not shown when type is specified`` () =
         let code =
@@ -264,4 +276,4 @@ type MyType() =
 
         let result = getTypeHints document
 
-        Assert.IsEmpty(result)
+        Assert.IsEmpty(result)