[TS/Python] Fix thisArg type for overloads in structs (#4453) (#4466)

Author: ncave

src/Fable.Cli/CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * [Python] Add `Math.DivRem` support for int, int64, and bigint (by @dbrattli)
 * [Python] Fix modulo with negative numbers using Python floored semantics instead of .NET truncated semantics for bigint (fixes #4462) (by @dbrattli)
 * [Beam] Fix `System.String.Concat` with 4+ arguments not being supported (by @dbrattli)
+* [TS/Python] Fix thisArg type for overloads in structs (#4453) (by @ncave)
 * [TS/Python] Fix invalid `this` argument type in structs (#4453) (by @ncave)
 * [JS/TS] Fix `N` format specifier (`ToString("N0")`, `String.Format("{0:N0}", ...)`) producing a trailing dot when precision is 0 (fix #2582) (by @MangelMaxime)
 * [JS/TS] Fix `C0` and `P0` format specifiers producing trailing dot (e.g., `"¤1,000."` → `"¤1,000"`) (by @MangelMaxime)

src/Fable.Compiler/CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * [Python] Add `Math.DivRem` support for int, int64, and bigint (by @dbrattli)
 * [Python] Fix modulo with negative numbers using Python floored semantics instead of .NET truncated semantics for bigint (fixes #4462) (by @dbrattli)
 * [Beam] Fix `System.String.Concat` with 4+ arguments not being supported (by @dbrattli)
+* [TS/Python] Fix thisArg type for overloads in structs (#4453) (by @ncave)
 * [TS/Python] Fix invalid `this` argument type in structs (#4453) (by @ncave)
 * [JS/TS] Fix `N` format specifier (`ToString("N0")`, `String.Format("{0:N0}", ...)`) producing a trailing dot when precision is 0 (fix #2582) (by @MangelMaxime)
 * [JS/TS] Fix `C0` and `P0` format specifiers producing trailing dot (e.g., `"¤1,000."` → `"¤1,000"`) (by @MangelMaxime)

src/Fable.Transforms/Fable2Babel.fs

@@ -1346,6 +1346,12 @@ module Util =
                 let body =
                     // TODO: If ident is not captured maybe we can just replace it with "this"
                     if isIdentUsed thisArg.Name body then
+                        let thisArgType =
+                            match thisArg.Type with
+                            | Replacements.Util.IsByRefType com typ -> typ
+                            | typ -> typ
+
+                        let thisArg = { thisArg with Type = thisArgType }
                         let thisIdent = Fable.IdentExpr { thisArg with Name = "this" }
 
                         let thisIdent =
@@ -3331,7 +3337,6 @@ but thanks to the optimisation done below we get
                     List.zip args tc.Args
                     |> List.map (fun (id, tcArg) ->
                         let ta = makeArgTypeAnnotation com ctx id
-
                         Parameter.parameter (tcArg, ?typeAnnotation = ta)
                     )
 

src/Fable.Transforms/Python/Fable2Python.Transforms.fs

@@ -83,6 +83,12 @@ let getMemberArgsAndBody (com: IPythonCompiler) ctx kind hasSpread (args: Fable.
 
             let body =
                 if isIdentUsed thisArg.Name body then
+                    let thisArgType =
+                        match thisArg.Type with
+                        | Replacements.Util.IsByRefType com typ -> typ
+                        | typ -> typ
+
+                    let thisArg = { thisArg with Type = thisArgType }
                     let thisKeyword = Fable.IdentExpr { thisArg with Name = "self" }
 
                     Fable.Let(thisArg, thisKeyword, body)

tests/Beam/TypeTests.fs

@@ -48,6 +48,7 @@ type ValueTypeR =
     val mutable X: float
     new(x: float) = { X = x }
     member this.IsEmpty() = this.X < 0.0
+    override this.ToString() = $"{this.X}"
 
 [<Struct>]
 type StructUnion = Value of string

tests/Dart/src/TypeTests.fs

@@ -269,6 +269,7 @@ open Util
 //     val mutable X: float
 //     new(x: float) = { X = x }
 //     member this.IsEmpty() = this.X < 0.0
+//     override this.ToString() = $"{this.X}"
 
 // [<Struct>]
 // type StructUnion = Value of string

tests/Js/Main/TypeTests.fs

@@ -272,6 +272,7 @@ type ValueTypeR =
     val mutable X: float
     new(x: float) = { X = x }
     member this.IsEmpty() = this.X < 0.0
+    override this.ToString() = $"{this.X}"
 
 [<Struct>]
 type StructUnion = Value of string

tests/Python/TestType.fs

@@ -303,6 +303,7 @@ type ValueTypeR =
     val mutable X: float
     new(x: float) = { X = x }
     member this.IsEmpty() = this.X < 0.0
+    override this.ToString() = $"{this.X}"
 
 [<Struct>]
 type StructUnion = Value of string

tests/Rust/tests/src/TypeTests.fs

@@ -269,6 +269,7 @@ type ValueTypeR =
     val mutable X: float
     new(x: float) = { X = x }
     member this.IsEmpty() = this.X < 0.0
+    override this.ToString() = $"{this.X}"
 
 [<Struct>]
 type StructUnion = Value of string