[Python] fix regression for record member method naming

src/Fable.Cli/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+* [Python] Fix record member method naming (by @dbrattli)
 * [Python] Fix regression, named arguments not being converted to snake_case (by @dbrattli)
 * [Python] Fix regression, erased interfaces should not generate code (#4277) (by @dbrattli)
 

src/Fable.Compiler/CHANGELOG.md

@@ -9,7 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-* Fix regression, Python erased interfaces should not generate code (#4277) (by @dbrattli)
+* [Python] Fix regression, record member method naming (by @dbrattli)
+* [Python] Fix regression, named arguments not being converted to snake_case (by @dbrattli)
+* [Python] Fix regression, erased interfaces should not generate code (#4277) (by @dbrattli)
 
 ### Changed
 

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

@@ -188,6 +188,10 @@ module Util =
             | None -> InstancePropertyBacking // Conservative fallback for unknown entities
         | _ -> RegularField
 
+    /// Checks if a field name is an actual record field (not a property/method defined on the record)
+    let isRecordField (ent: Fable.Entity) (fieldName: string) =
+        ent.FSharpFields |> List.exists (fun f -> f.Name = fieldName)
+
     // Helper function to apply the appropriate naming convention based on field type and naming kind
     let applyFieldNaming
         (com: IPythonCompiler)
@@ -202,9 +206,8 @@ module Util =
             match narrowedType with
             | Fable.AnonymousRecordType _ when handleAnonymousRecords -> fieldName // Use the field name as is for anonymous records
             | Fable.DeclaredType(entityRef, _) ->
-                // Only apply naming convention for user-defined F# Records (not built-in F# Core types)
                 match com.TryGetEntity entityRef with
-                | Some ent when shouldUseRecordFieldNamingForRef entityRef ent ->
+                | Some ent when shouldUseRecordFieldNamingForRef entityRef ent && isRecordField ent fieldName ->
                     fieldName |> Naming.toRecordFieldSnakeCase |> Helpers.clean
                 | _ -> fieldName |> Naming.toPythonNaming // Fallback to Python naming for other types
             | _ -> fieldName |> Naming.toPropertyNaming

tests/Python/TestRecordType.fs

@@ -190,4 +190,13 @@ type CasingRecord =
 let ``test Record with both camel-case and pascal-case fields don't conflict`` () =
     let x = { firstName = "John"; FirstName = "Jane" }
     equal "John" x.firstName
-    equal "Jane" x.FirstName
+    equal "Jane" x.FirstName
+
+type RecordWithProperty =
+    { items: string list }
+    member this.fullName = String.concat " - " this.items
+
+[<Fact>]
+let ``test Record property access uses correct naming`` () =
+    let x = { items = ["Hello"; "World"] }
+    equal "Hello - World" x.fullName