Fixed attached indexers

src/Fable.Transforms/FSharp2Fable.Util.fs

@@ -199,8 +199,17 @@ type FsAbstractSignature(s: FSharpAbstractSignature) =
         member _.DeclaringType = TypeHelpers.makeType Map.empty s.DeclaringType
 
 type FsMemberFunctionOrValue(m: FSharpMemberOrFunctionOrValue) =
+    static member CompiledName(m: FSharpMemberOrFunctionOrValue) =
+        if FsMemberFunctionOrValue.IsGetter(m) ||
+            FsMemberFunctionOrValue.IsSetter(m)
+        then Naming.removeGetSetPrefix m.CompiledName
+        else m.CompiledName
+
     static member DisplayName(m: FSharpMemberOrFunctionOrValue) =
-        Naming.removeGetSetPrefix m.DisplayNameCore
+        if FsMemberFunctionOrValue.IsGetter(m) ||
+            FsMemberFunctionOrValue.IsSetter(m)
+        then Naming.removeGetSetPrefix m.DisplayNameCore
+        else m.DisplayNameCore
 
     // We don't consider indexer properties as getters/setters so they're always compiled as methods
     static member IsGetter(m: FSharpMemberOrFunctionOrValue) =
@@ -692,7 +701,7 @@ module Helpers =
             |> Option.defaultValue false
 
         v.IsModuleValueOrMember && not v.HasSignatureFile && parentHasSignatureFile ()
-    
+
     let isNotPrivate (memb: FSharpMemberOrFunctionOrValue) =
         if memb.IsCompilerGenerated then false
         elif topLevelBindingHiddenBySignatureFile memb then false
@@ -1842,19 +1851,11 @@ module Util =
             let arg = callInfo.Args |> List.tryHead |> Option.defaultWith makeNull
             Fable.Set(callee, Fable.FieldSet(info.name), membType, arg, r)
         else
-            // If the entity is decorated with AttachMembers, we need to remove the get/set prefix
-            // See https://github.com/fable-compiler/Fable/issues/3494
-            let membName =
-                if isAttachMembersEntity com entity then
-                    Naming.removeGetSetPrefix info.name
-                else
-                    info.name
-
             let entityGenParamsCount = entity.GenericParameters.Count
             let callInfo =
                 if callInfo.GenericArgs.Length < entityGenParamsCount then callInfo
                 else { callInfo with GenericArgs = List.skip entityGenParamsCount callInfo.GenericArgs }
-            getField callee membName |> makeCall r typ callInfo
+            getField callee info.name |> makeCall r typ callInfo
 
     let failReplace (com: IFableCompiler) ctx r (info: Fable.ReplaceCallInfo) (thisArg: Fable.Expr option) =
         let msg =

src/Fable.Transforms/FSharp2Fable.fs

@@ -1405,7 +1405,7 @@ let private transformExplicitlyAttachedMember (com: FableCompiler) (ctx: Context
     let name, isMangled =
         match Compiler.Language with
         | Rust -> getMemberDeclarationName com memb |> fst, true
-        | _ -> Naming.removeGetSetPrefix memb.CompiledName, false
+        | _ -> FsMemberFunctionOrValue.CompiledName(memb), false
     com.AddAttachedMember(entFullName, isMangled=false, memb =
         { Name = name
           Body = body

tests/Js/Main/TypeTests.fs

@@ -72,6 +72,19 @@ type TestType7(a1, a2, a3) =
     let arr = [|a1; a2; a3|]
     member _.Value with get(i) = arr.[i] and set(i) (v) = arr.[i] <- v
 
+[<Fable.Core.AttachMembers>]
+type TestTypeAttached(a1, a2, a3) =
+    let arr = [| a1; a2; a3 |]
+    member _.Value1
+        with get () = arr.[1]
+        and set (v) = arr.[1] <- v
+    member _.Value
+        with get (i) = arr.[i]
+        and set (i) (v) = arr.[i] <- v
+    member _.Item
+        with get (i) = arr.[i]
+        and set (i) (v) = arr.[i] <- v
+
 type A  = { thing: int } with
     member x.show() = string x.thing
     static member show (x: A) = "Static: " + (string x.thing)
@@ -633,6 +646,18 @@ let tests =
         t.Value(1) |> equal 5
         t.Value(2) |> equal 3
 
+    testCase "Attached Getters Setters and Indexers work" <| fun () ->
+        let t = TestTypeAttached(1, 2, 3)
+        t.Value1 |> equal 2
+        t.Value1 <- 22
+        t.Value1 |> equal 22
+        t.Value(0) |> equal 1
+        t.Value(0) <- 11
+        t.Value(0) |> equal 11
+        t[2] |> equal 3
+        t[2] <- 33
+        t[2] |> equal 33
+
     testCase "Statically resolved instance calls work" <| fun () ->
         let a = { thing = 5 }
         let b = { label = "five" }

tests/Python/TestType.fs

@@ -83,6 +83,19 @@ type Type7Test(a1, a2, a3) =
         with get (i) = arr.[i]
         and set (i) (v) = arr.[i] <- v
 
+[<Fable.Core.AttachMembers>]
+type TypeAttachedTest(a1, a2, a3) =
+    let arr = [| a1; a2; a3 |]
+    member _.Value1
+        with get () = arr.[1]
+        and set (v) = arr.[1] <- v
+    member _.Value
+        with get (i) = arr.[i]
+        and set (i) (v) = arr.[i] <- v
+    member _.Item
+        with get (i) = arr.[i]
+        and set (i) (v) = arr.[i] <- v
+
 type A =
     { thing: int }
     member x.show() = string x.thing
@@ -698,6 +711,19 @@ let ``test Getter and Setter with indexer work`` () =
     t.Value(1) |> equal 5
     t.Value(2) |> equal 3
 
+[<Fact>]
+let ``test Attached Getters Setters and Indexers work`` () =
+    let t = TypeAttachedTest(1, 2, 3)
+    t.Value1 |> equal 2
+    t.Value1 <- 22
+    t.Value1 |> equal 22
+    t.Value(0) |> equal 1
+    t.Value(0) <- 11
+    t.Value(0) |> equal 11
+    t.[2] |> equal 3
+    t.[2] <- 33
+    t.[2] |> equal 33
+
 [<Fact>]
 let ``test Statically resolved instance calls work`` () =
     let a = { thing = 5 }

tests/Rust/tests/src/TypeTests.fs

@@ -71,6 +71,19 @@ type TestType7(a1, a2, a3) =
     let arr = [|a1; a2; a3|]
     member _.Value with get(i) = arr[i] and set(i) (v) = arr[i] <- v
 
+[<Fable.Core.AttachMembers>]
+type TestTypeAttached(a1, a2, a3) =
+    let arr = [| a1; a2; a3 |]
+    member _.Value1
+        with get () = arr.[1]
+        and set (v) = arr.[1] <- v
+    member _.Value
+        with get (i) = arr.[i]
+        and set (i) (v) = arr.[i] <- v
+    member _.Item
+        with get (i) = arr.[i]
+        and set (i) (v) = arr.[i] <- v
+
 type A  = { thing: int } with
     member x.show() = string x.thing
     static member show (x: A) = "Static: " + (string x.thing)
@@ -632,6 +645,19 @@ let ``Getter and Setter with indexer work`` () =
     t.Value(1) |> equal 5
     t.Value(2) |> equal 3
 
+[<Fact>]
+let ``Attached Getters Setters and Indexers work`` () =
+    let t = TestTypeAttached(1, 2, 3)
+    t.Value1 |> equal 2
+    t.Value1 <- 22
+    t.Value1 |> equal 22
+    t.Value(0) |> equal 1
+    t.Value(0) <- 11
+    t.Value(0) |> equal 11
+    t[2] |> equal 3
+    t[2] <- 33
+    t[2] |> equal 33
+
 [<Fact>]
 let ``Statically resolved instance calls work`` () =
     let a = { thing = 5 }