tests/RedundantNewKeyword: new 'use' testcase

Given that using the 'use' keyword on a non-IDisposable type
would be flagged by the F# compiler as an (FS0193) error,
we should assume that the type implements IDisposable when
this keyword is present (because it's logical to assume that
you run FSharpLint as an extra layer of correctness on top of
compilation itself).

Co-authored-by: webwarrior-ws <[email protected]>

Author: knocte

tests/FSharpLint.Core.Tests/Rules/Conventions/RedundantNewKeyword.fs

@@ -74,3 +74,15 @@ module Program
 """
 
         Assert.IsTrue this.ErrorsExist
+
+    [<Test>]
+    member this.``unresolved type with 'use' should not give rule violations``() =
+        this.Parse """
+module Program
+    let SomeFunc() =
+        use foo = new UnresolvedType()
+        foo.Foo
+"""
+
+        Assert.IsFalse this.ErrorsExist
+