Propagate comments from record fields to gentype output

CHANGELOG.md

@@ -12,6 +12,10 @@
 
 # 11.0.0-beta.5 (Unreleased)
 
+#### :rocket: New Feature
+
+- GenType: Propagate comments from record fields to emitted TypeScript types. https://github.com/rescript-lang/rescript-compiler/pull/6333
+
 # 11.0.0-beta.4
 
 #### :rocket: New Feature

jscomp/gentype/Annotation.ml

@@ -33,7 +33,10 @@ let tagIsOneOfTheGenTypeAnnotations s =
 let tagIsGenTypeIgnoreInterface s =
   s = "genType.ignoreInterface" || s = "gentype.ignoreInterface"
 
-let tagIsOcamlDoc s = s = "ocaml.doc"
+let tagIsDoc s =
+  match s with
+  | "ocaml.doc" | "res.doc" -> true
+  | _ -> false
 let tagIsInternLocal s = s = "internal.local"
 
 let rec getAttributePayload checkText (attributes : Typedtree.attributes) =
@@ -143,12 +146,19 @@ let getAttributeImportRenaming attributes =
     (Some importString, Some renameString)
   | _ -> (None, genTypeAsRenaming)
 
-let getDocString attributes =
-  let docPayload = attributes |> getAttributePayload tagIsOcamlDoc in
+let getDocPayload attributes =
+  let docPayload = attributes |> getAttributePayload tagIsDoc in
   match docPayload with
-  | Some (_, StringPayload docString) -> "/** " ^ docString ^ " */\n"
+  | Some (_, StringPayload docString) -> Some docString
+  | _ -> None
+
+let mkDocString maybeDoc =
+  match maybeDoc with
+  | Some docString -> "/** " ^ docString ^ " */\n"
   | _ -> ""
 
+let getDocString attributes = getDocPayload attributes |> mkDocString
+
 let hasAttribute checkText (attributes : Typedtree.attributes) =
   getAttributePayload checkText attributes <> None
 

jscomp/gentype/EmitType.ml

@@ -47,6 +47,7 @@ let typeReactRef ~type_ =
           nameJS = reactRefCurrent;
           optional = Mandatory;
           type_ = Null type_;
+          docString = None;
         };
       ] )
 
@@ -162,12 +163,13 @@ let rec renderType ~(config : Config.t) ?(indent = None) ~typeNameIsInterface
              type_ |> renderType ~config ~indent ~typeNameIsInterface ~inFunType)
     in
     let noPayloadsRendered = noPayloads |> List.map labelJSToString in
-    let field ~name value =
+    let field ~name ?docString value =
       {
         mutable_ = Mutable;
         nameJS = name;
         optional = Mandatory;
         type_ = TypeVar value;
+        docString;
       }
     in
     let fields fields =
@@ -232,7 +234,7 @@ let rec renderType ~(config : Config.t) ?(indent = None) ~typeNameIsInterface
            ^ "| "))
 
 and renderField ~config ~indent ~typeNameIsInterface ~inFunType
-    {mutable_; nameJS = lbl; optional; type_} =
+    {mutable_; nameJS = lbl; optional; type_; docString} =
   let optMarker =
     match optional == Optional with
     | true -> "?"
@@ -249,8 +251,16 @@ and renderField ~config ~indent ~typeNameIsInterface ~inFunType
     | false -> EmitText.quotes lbl
   in
 
-  Indent.break ~indent ^ mutMarker ^ lbl ^ optMarker ^ ": "
-  ^ (type_ |> renderType ~config ~indent ~typeNameIsInterface ~inFunType)
+  let defStr =
+    mutMarker ^ lbl ^ optMarker ^ ": "
+    ^ (type_ |> renderType ~config ~indent ~typeNameIsInterface ~inFunType)
+  in
+  match docString with
+  | None -> Indent.break ~indent ^ defStr
+  | Some docString ->
+    (* Always print comments on newline before definition. *)
+    let indentStr = indent |> Option.value ~default:"" in
+    "\n" ^ indentStr ^ "/**" ^ docString ^ "*/\n" ^ indentStr ^ defStr
 
 and renderFields ~config ~indent ~inFunType ~typeNameIsInterface fields =
   let indent1 = indent |> Indent.more in

jscomp/gentype/ExportModule.ml

@@ -39,6 +39,7 @@ and exportModuleItemToFields =
              nameJS = fieldName;
              optional = Mandatory;
              type_ = typeForType;
+             docString = None;
            }
          in
          let fieldForValue = {fieldForType with type_ = typeForValue} in

jscomp/gentype/GenTypeCommon.ml

@@ -78,6 +78,7 @@ and field = {
   nameJS: string;
   optional: optional;
   type_: type_;
+  docString: string option;
 }
 
 and function_ = {argTypes: argType list; retType: type_; typeVars: string list}

jscomp/gentype/NamedArgs.ml

@@ -14,13 +14,25 @@ let rec groupReversed ~revCurGroup ~revResult labeledTypes =
     (* Add it to the current group, not result. *)
     groupReversed
       ~revCurGroup:
-        ({mutable_ = Immutable; nameJS = name; optional = Optional; type_}
+        ({
+           mutable_ = Immutable;
+           nameJS = name;
+           optional = Optional;
+           type_;
+           docString = None;
+         }
         :: revCurGroup)
       ~revResult tl
   | _, (Label name, type_) :: tl ->
     groupReversed
       ~revCurGroup:
-        ({mutable_ = Immutable; nameJS = name; optional = Mandatory; type_}
+        ({
+           mutable_ = Immutable;
+           nameJS = name;
+           optional = Mandatory;
+           type_;
+           docString = None;
+         }
         :: revCurGroup)
       ~revResult tl
   | [], [] -> revResult

jscomp/gentype/TranslateTypeDeclarations.ml

@@ -103,23 +103,26 @@ let traslateDeclarationKind ~config ~loc ~outputFileRelative ~resolver
                mutability,
                ld_type
                |> TranslateTypeExprFromTypes.translateTypeExprFromTypes ~config
-                    ~typeEnv ))
+                    ~typeEnv,
+               Annotation.getDocPayload ld_attributes ))
     in
     let dependencies =
       fieldTranslations
-      |> List.map (fun (_, _, {TranslateTypeExprFromTypes.dependencies}) ->
+      |> List.map (fun (_, _, {TranslateTypeExprFromTypes.dependencies}, _) ->
              dependencies)
       |> List.concat
     in
     let fields =
       fieldTranslations
-      |> List.map (fun (name, mutable_, {TranslateTypeExprFromTypes.type_}) ->
+      |> List.map
+           (fun (name, mutable_, {TranslateTypeExprFromTypes.type_}, docString)
+           ->
              let optional, type1 =
                match type_ with
                | Option type1 when isOptional name -> (Optional, type1)
                | _ -> (Mandatory, type_)
              in
-             {mutable_; nameJS = name; optional; type_ = type1})
+             {mutable_; nameJS = name; optional; type_ = type1; docString})
     in
     let type_ =
       match fields with

jscomp/gentype/TranslateTypeExprFromTypes.ml

@@ -45,7 +45,7 @@ let translateObjType closedFlag fieldsTranslations =
              | _ -> (Mandatory, t)
            in
            let name = name |> Runtime.mangleObjectField in
-           {mutable_; nameJS = name; optional; type_})
+           {mutable_; nameJS = name; optional; type_; docString = None})
   in
   let type_ = Object (closedFlag, fields) in
   {dependencies; type_}
@@ -126,6 +126,7 @@ let translateConstr ~config ~paramsTranslation ~(path : Path.t) ~typeEnv =
                 nameJS = "contents";
                 optional = Mandatory;
                 type_ = paramTranslation.type_;
+                docString = None;
               };
             ] );
     }
@@ -465,7 +466,7 @@ and signatureToModuleRuntimeRepresentation ~config ~typeVarsGen ~typeEnv
     |> List.map (fun signatureItem ->
            match signatureItem with
            | Types.Sig_value (_id, {val_kind = Val_prim _}) -> ([], [])
-           | Types.Sig_value (id, {val_type = typeExpr}) ->
+           | Types.Sig_value (id, {val_type = typeExpr; val_attributes}) ->
              let {dependencies; type_} =
                typeExpr
                |> translateTypeExprFromTypes_ ~config ~typeVarsGen ~typeEnv
@@ -476,6 +477,7 @@ and signatureToModuleRuntimeRepresentation ~config ~typeVarsGen ~typeEnv
                  nameJS = id |> Ident.name;
                  optional = Mandatory;
                  type_;
+                 docString = Annotation.getDocPayload val_attributes;
                }
              in
              (dependencies, [field])
@@ -499,6 +501,8 @@ and signatureToModuleRuntimeRepresentation ~config ~typeVarsGen ~typeEnv
                  nameJS = id |> Ident.name;
                  optional = Mandatory;
                  type_;
+                 docString =
+                   Annotation.getDocPayload moduleDeclaration.md_attributes;
                }
              in
              (dependencies, [field])

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

@@ -0,0 +1,30 @@
+/* TypeScript file generated from Comments.res by genType. */
+/* eslint-disable import/first */
+
+
+// @ts-ignore: Implicit any on import
+import * as CommentsBS__Es6Import from './Comments.bs';
+const CommentsBS: any = CommentsBS__Es6Import;
+
+// tslint:disable-next-line:interface-over-type-literal
+export type DecideSubject_payload = { 
+/** A hint to use as a guide when thinking of your poem.*/
+readonly hint: string };
+
+// tslint:disable-next-line:max-classes-per-file 
+export abstract class DecideSubject_input { protected opaque!: any }; /* simulate opaque types */
+
+// tslint:disable-next-line:interface-over-type-literal
+export type DecideSubject_output = {
+  /** The text of the poem.*/
+  readonly text: string; 
+  /** The prompt used to generate the poem.*/
+  readonly prompt: string; 
+  /** The system prompt used to generate the poem.*/
+  readonly systemPrompt: string
+};
+
+/**  Decide on a subject matter for a poem. */
+export const DecideSubject__placeholder: (run:string, times:number) => void = CommentsBS.DecideSubject._placeholder;
+
+export const DecideSubject: { _placeholder: (run:string, times:number) => void } = CommentsBS.DecideSubject

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

@@ -0,0 +1,24 @@
+@genType /** A module for deciding on a subject matter for a poem.*/
+module DecideSubject = {
+  type payload = {
+    /** A hint to use as a guide when thinking of your poem.*/
+    hint: string,
+  }
+  /** The input used to generate the prompt and system prompt.*/
+  type input
+  /** The output from evaluating the llm prompt*/
+  type output = {
+    /** The text of the poem.*/
+    text: string,
+    /** The prompt used to generate the poem.*/
+    prompt: string,
+    /** The system prompt used to generate the poem.*/
+    systemPrompt: string,
+  }
+
+  @genType /** Decide on a subject matter for a poem.*/
+  let _placeholder = (
+    @ocaml.doc("The runner specification") run: string,
+    @ocaml.doc("The number of times to cycle through the runner") times: int,
+  ) => (run, times)->ignore
+}