Remove special treatment of {x:option<t>} as optional field.

This is a breaking changes, but aligns more closely with TS.

The two TS types:

```ts
type t1 = { x?: string };

type t2 = { x: (undefined | string) };
```

now correspond to the ReScript types:
```res
@genType
type t1 = {x?: string}

@genType
type t2 = {x: Js.undefined<string>}
```

The special treatment of fields of option type comes from a time where records with optional fields did not exist.

Author: cristianoc

jscomp/gentype/TranslateSignatureFromTypes.ml

@@ -12,8 +12,9 @@ let translateTypeDeclarationFromTypes ~config ~outputFileRelative ~resolver
     Log_.item "Translate Types.type_declaration %s\n" typeName;
   let declarationKind =
     match type_kind with
-    | Type_record (labelDeclarations, _) ->
-      TranslateTypeDeclarations.RecordDeclarationFromTypes labelDeclarations
+    | Type_record (labelDeclarations, recordRepresentation) ->
+      TranslateTypeDeclarations.RecordDeclarationFromTypes
+        (labelDeclarations, recordRepresentation)
     | Type_variant constructorDeclarations
       when not
              (TranslateTypeDeclarations.hasSomeGADTLeaf constructorDeclarations)

jscomp/gentype/TranslateTypeDeclarations.ml

@@ -1,7 +1,8 @@
 open GenTypeCommon
 
 type declarationKind =
-  | RecordDeclarationFromTypes of Types.label_declaration list
+  | RecordDeclarationFromTypes of
+      Types.label_declaration list * Types.record_representation
   | GeneralDeclaration of Typedtree.core_type option
   | GeneralDeclarationFromTypes of Types.type_expr option
       (** As the above, but from Types not Typedtree *)
@@ -78,7 +79,12 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
     in
     {CodeItem.importTypes; exportFromTypeDeclaration}
   in
-  let translateLabelDeclarations labelDeclarations =
+  let translateLabelDeclarations ~recordRepresentation labelDeclarations =
+    let isOptional l =
+      match recordRepresentation with
+      | Types.Record_optional_labels lbls -> List.mem l lbls
+      | _ -> false
+    in
     let fieldTranslations =
       labelDeclarations
       |> List.map (fun {Types.ld_id; ld_mutable; ld_type; ld_attributes} ->
@@ -111,7 +117,7 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
            ->
              let optional, type1 =
                match type_ with
-               | Option type1 -> (Optional, type1)
+               | Option type1 when isOptional nameRE -> (Optional, type1)
                | _ -> (Mandatory, type_)
              in
              {mutable_; nameJS; nameRE; optional; type_ = type1})
@@ -196,9 +202,10 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
     in
     {translation with type_} |> handleGeneralDeclaration
     |> returnTypeDeclaration
-  | RecordDeclarationFromTypes labelDeclarations, None ->
+  | RecordDeclarationFromTypes (labelDeclarations, recordRepresentation), None
+    ->
     let {TranslateTypeExprFromTypes.dependencies; type_} =
-      labelDeclarations |> translateLabelDeclarations
+      labelDeclarations |> translateLabelDeclarations ~recordRepresentation
     in
     let importTypes =
       dependencies
@@ -227,7 +234,11 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
                  |> TranslateTypeExprFromTypes.translateTypeExprsFromTypes
                       ~config ~typeEnv
                | Cstr_record labelDeclarations ->
-                 [labelDeclarations |> translateLabelDeclarations]
+                 [
+                   labelDeclarations
+                   |> translateLabelDeclarations
+                        ~recordRepresentation:Types.Record_regular;
+                 ]
              in
              let inlineRecord =
                match constructorArgs with
@@ -342,8 +353,8 @@ let translateTypeDeclaration ~config ~outputFileRelative ~recursive ~resolver
   in
   let declarationKind =
     match typ_type.type_kind with
-    | Type_record (labelDeclarations, _) ->
-      RecordDeclarationFromTypes labelDeclarations
+    | Type_record (labelDeclarations, recordRepresentation) ->
+      RecordDeclarationFromTypes (labelDeclarations, recordRepresentation)
     | Type_variant constructorDeclarations ->
       VariantDeclarationFromTypes constructorDeclarations
     | Type_abstract -> GeneralDeclaration typ_manifest

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

@@ -13,6 +13,12 @@ const CoreBS: any = CoreBS__Es6Import;
 // tslint:disable-next-line:interface-over-type-literal
 export type variant = "A" | { tag: "B"; value: string };
 
+// tslint:disable-next-line:interface-over-type-literal
+export type t1 = { readonly x?: string };
+
+// tslint:disable-next-line:interface-over-type-literal
+export type t2 = { readonly x: (undefined | string) };
+
 export const null0: (x:(null | number)) => (null | number) = CoreBS.null0;
 
 export const null1: (x:(null | number)) => (null | number) = CoreBS.null1;

jscomp/gentype_tests/typescript-react-example/src/Core.res

@@ -68,3 +68,9 @@ let option0 = (x: option<string>) => x
 
 @genType
 let option1 = (x: option<variant>) => x
+
+@genType
+type t1 = {x?: string}
+
+@genType
+type t2 = {x: Js.undefined<string>}

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

@@ -107,7 +107,7 @@ import type {polyType as $$polyType} from './MyMath';
 import type {stringFunction as $$stringFunction} from './MyMath';
 
 // tslint:disable-next-line:interface-over-type-literal
-export type point = { readonly x: number; readonly y?: number };
+export type point = { readonly x: number; readonly y: (undefined | number) };
 
 // tslint:disable-next-line:interface-over-type-literal
 export type numberOrString = $$numberOrString;

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

@@ -6,4 +6,4 @@
 export type someType = { readonly crop?: string; readonly "fp-z"?: string };
 
 // tslint:disable-next-line:interface-over-type-literal
-export type someType2 = { readonly crop?: string; readonly "fp-z"?: string };
+export type someType2 = { readonly crop: (undefined | string); readonly "fp-z": (undefined | string) };

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

@@ -16,21 +16,21 @@ import type {list} from '../src/shims/RescriptPervasives.shim';
 export type coord = {
   readonly x: number; 
   readonly y: number; 
-  readonly z?: number
+  readonly z: (undefined | number)
 };
 
 // tslint:disable-next-line:interface-over-type-literal
 export type person = {
   readonly name: string; 
   readonly age: number; 
-  readonly address?: string
+  readonly address: (undefined | string)
 };
 
 // tslint:disable-next-line:interface-over-type-literal
 export type business = {
   readonly name: string; 
-  readonly owner?: person; 
-  readonly address?: string
+  readonly owner: (undefined | person); 
+  readonly address: (undefined | string)
 };
 
 // tslint:disable-next-line:interface-over-type-literal

jscomp/gentype_tests/typescript-react-example/src/VariantsWithPayload.res

@@ -1,6 +1,6 @@
 type payload = {
   x: int,
-  y: option<string>,
+  y?: string,
 }
 
 type withPayload = [