GenType: distinguish inline records from unary variant cases of object type.

Fixes #6584

Author: cristianoc

CHANGELOG.md

@@ -16,6 +16,10 @@
 
 - experimental support of tagged template literals, eg ```sql`select * from ${table}```. https://github.com/rescript-lang/rescript-compiler/pull/6250
 
+#### :bug: Bug Fix
+
+- GenType: distinguish inline records from unary variant cases of object type. https://github.com/rescript-lang/rescript-compiler/pull/6586
+
 # 11.0.1
 
 #### :bug: Bug Fix

jscomp/gentype/EmitType.ml

@@ -203,7 +203,7 @@ let rec renderType ~(config : Config.t) ?(indent = None) ~typeNameIsInterface
                  |> field ~name:(Runtime.jsVariantValue ~polymorphic);
                ]
                |> fields
-             | false, Object (_, flds) ->
+             | false, Object (Inline, flds) ->
                (* inlined record *)
                tagField :: flds |> fields
              | false, type_ ->

jscomp/gentype/GenTypeCommon.ml

@@ -62,7 +62,7 @@ let labelJSToString case =
   | IntLabel i -> i
   | StringLabel s -> s |> EmitText.quotes
 
-type closedFlag = Open | Closed
+type closedFlag = Open | Closed | Inline
 
 type type_ =
   | Array of type_ * mutable_

jscomp/gentype/TranslateTypeDeclarations.ml

@@ -85,7 +85,8 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
     in
     {CodeItem.importTypes; exportFromTypeDeclaration}
   in
-  let translateLabelDeclarations ~recordRepresentation labelDeclarations =
+  let translateLabelDeclarations ?(inline = false) ~recordRepresentation
+      labelDeclarations =
     let isOptional l =
       match recordRepresentation with
       | Types.Record_optional_labels lbls -> List.mem l lbls
@@ -131,7 +132,7 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
     let type_ =
       match fields with
       | [field] when unboxedAnnotation -> field.type_
-      | _ -> Object (Closed, fields)
+      | _ -> Object ((if inline then Inline else Closed), fields)
     in
     {TranslateTypeExprFromTypes.dependencies; type_}
   in
@@ -244,7 +245,7 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
                | Cstr_record labelDeclarations ->
                  [
                    labelDeclarations
-                   |> translateLabelDeclarations
+                   |> translateLabelDeclarations ~inline:true
                         ~recordRepresentation:Types.Record_regular;
                  ]
              in

jscomp/gentype_tests/typescript-react-example/package-lock.json

@@ -41,7 +41,8 @@ export type unboxedBinary = { TAG: "UB"; _0: typeD; _1: number };
 export type inline = 
     { TAG: "I"; readonly i: number; readonly j: number }
   | { TAG: "J"; readonly i: number; readonly j: number }
-  | { TAG: "K"; _0: number; _1: number };
+  | { TAG: "K"; _0: number; _1: number }
+  | { TAG: "L"; _0: { readonly j: number; readonly i: number } };
 
 export const makeVariant: () => typeL = NestedVariantsJS.makeVariant as any;
 

jscomp/gentype_tests/typescript-react-example/src/NestedVariants.gen.tsx

@@ -61,6 +61,7 @@ type inline =
   | I({i: int, j: int})
   | J({i: int, j: int})
   | K(int, int)
+  | L({"i": int, "j": int})
 
 @genType
 let testBoxedBinary = (_: boxedBinary) => 34
@@ -74,5 +75,6 @@ let testInline = x =>
   | I(q) => I({...q, i: q.i})
   | J(q) => J(q)
   | K(a, b) => K(b, a)
+  | L(q) => L(q)
   }