Only update typar name when TyparStaticReq matches.

member-contrains-type-extension.fsx

@@ -0,0 +1,23 @@
+module Extensions
+
+type DataItem<'data> =
+    { Identifier: string
+      Label: string
+      Data: 'data }
+
+    static member Create<'data>(identifier: string, label: string, data: 'data) =
+        { DataItem.Identifier = identifier
+          DataItem.Label = label
+          DataItem.Data = data }
+
+#nowarn "957"
+
+type DataItem< ^input> with
+
+    static member inline Create(item: ^input) =
+        let stringValue: string = (^input: (member get_StringValue: unit -> string) (item))
+
+        let friendlyStringValue: string =
+            (^input: (member get_FriendlyStringValue: unit -> string) (item))
+
+        DataItem.Create< ^input>(stringValue, friendlyStringValue, item)

src/Compiler/Checking/CheckDeclarations.fs

@@ -4049,8 +4049,10 @@ module TcDeclarations =
                     if tcref.TyparsNoRange.Length = synTypars.Length then
                         (tcref.TyparsNoRange, synTypars)
                         ||> List.zip
-                        |> List.iter (fun (typar, SynTyparDecl.SynTyparDecl (typar = SynTypar (ident = untypedIdent))) ->
-                            typar.SetIdent(untypedIdent)
+                        |> List.iter (fun (typar, SynTyparDecl.SynTyparDecl (typar = tp)) ->
+                            let (SynTypar(ident = untypedIdent; staticReq = sr)) = tp
+                            if typar.StaticReq = sr then
+                                typar.SetIdent(untypedIdent)
                         )
 
                     res

tests/FSharp.Compiler.ComponentTests/ConstraintSolver/MemberConstraints.fs

@@ -46,3 +46,31 @@ else ()
         |> run
         |> shouldSucceed
         |> withExitCode 0
+
+    [<Fact>]
+    let ``Respect nowarn 957 for extension method`` () =
+        FSharp """        
+module Foo
+
+type DataItem<'data> =
+    { Identifier: string
+      Label: string
+      Data: 'data }
+
+    static member Create<'data>(identifier: string, label: string, data: 'data) =
+        { DataItem.Identifier = identifier
+          DataItem.Label = label
+          DataItem.Data = data }
+
+#nowarn "957"
+
+type DataItem< ^input> with
+
+    static member inline Create(item: ^input) =
+        let stringValue: string = (^input: (member get_StringValue: unit -> string) (item))
+        let friendlyStringValue: string = (^input: (member get_FriendlyStringValue: unit -> string) (item))
+
+        DataItem.Create< ^input>(stringValue, friendlyStringValue, item)
+"""
+        |> compile
+        |> shouldSucceed

tests/FSharp.Compiler.ComponentTests/Signatures/TypeTests.fs

@@ -133,6 +133,49 @@ type System.Collections.Concurrent.ConcurrentDictionary<'key,'value> with
 
   member TryFind: key: 'key -> 'value option"""
 
+[<Fact>]
+let ``Don't update typar name in type extension when TyparStaticReq doesn't match`` () =
+    FSharp """        
+module Extensions
+
+type DataItem<'data> =
+    { Identifier: string
+      Label: string
+      Data: 'data }
+
+    static member Create<'data>(identifier: string, label: string, data: 'data) =
+        { DataItem.Identifier = identifier
+          DataItem.Label = label
+          DataItem.Data = data }
+
+#nowarn "957"
+
+type DataItem< ^input> with
+
+    static member inline Create(item: ^input) =
+        let stringValue: string = (^input: (member get_StringValue: unit -> string) (item))
+
+        let friendlyStringValue: string =
+            (^input: (member get_FriendlyStringValue: unit -> string) (item))
+
+        DataItem.Create< ^input>(stringValue, friendlyStringValue, item)
+"""
+    |> printSignatures
+    |> should equal
+        """
+module Extensions
+
+type DataItem<'data> =
+  {
+    Identifier: string
+    Label: string
+    Data: 'data
+  }
+
+  static member inline Create: item: ^input -> DataItem<^input> when ^input: (member get_StringValue: unit -> string) and ^input: (member get_FriendlyStringValue: unit -> string)
+
+  static member Create<'data> : identifier: string * label: string * data: 'data -> DataItem<'data>"""
+
 [<Fact>]
 let ``ValText for C# abstract member override`` () =
     let csharp = CSharp """