Fix #1895: casting anon rec, parent interfaces

src/Fable.Transforms/FSharp2Fable.Util.fs

@@ -244,14 +244,17 @@ module Helpers =
             | None -> false
         | _ -> false
 
+    let rec getAllInterfaceMembers (ent: FSharpEntity) =
+        seq {
+            yield! ent.MembersFunctionsAndValues
+            for parent in ent.DeclaredInterfaces do
+                match tryDefinition parent with
+                | Some(e, _) -> yield! getAllInterfaceMembers e
+                | None -> ()
+        }
+
     let rec isInterfaceEmpty (ent: FSharpEntity) =
-        ent.MembersFunctionsAndValues.Count = 0
-            && (if ent.DeclaredInterfaces.Count > 0 then
-                    ent.DeclaredInterfaces |> Seq.forall (fun ifc ->
-                        match tryDefinition ifc with
-                        | Some(e, _) -> isInterfaceEmpty e
-                        | None -> true)
-                else true)
+        getAllInterfaceMembers ent |> Seq.isEmpty
 
     /// Test if the name corresponds to this interface or anyone in its hierarchy
     let rec testInterfaceHierarcy interfaceFullname interfaceType =

src/Fable.Transforms/Replacements.fs

@@ -1124,7 +1124,7 @@ let fableCoreLib (com: ICompiler) (ctx: Context) r t (i: CallInfo) (thisArg: Exp
             | NewAnonymousRecord(_, exprs, fieldNames, _, _),
               [_; (_,DeclaredType(ent, []))] when ent.IsInterface ->
                 // TODO: Check also if there are extra fields in the record not present in the interface?
-                (None, ent.MembersFunctionsAndValues |> Seq.filter (fun memb -> memb.IsPropertyGetterMethod))
+                (None, FSharp2Fable.Helpers.getAllInterfaceMembers ent |> Seq.filter (fun memb -> memb.IsPropertyGetterMethod))
                 ||> Seq.fold (fun err memb ->
                     match err with
                     | Some _ -> err