Support migration to async_iterable (#2087)

Author: saschanaz

package-lock.json

@@ -46,10 +46,10 @@
     "@types/webidl2": "^24.4.3",
     "@typescript-eslint/eslint-plugin": "^8",
     "@typescript-eslint/parser": "^8",
-    "@webref/css": "^6.12.7",
-    "@webref/elements": "^2.3.0",
-    "@webref/events": "^1.11.3",
-    "@webref/idl": "^3.46.1",
+    "@webref/css": "^6.23.6",
+    "@webref/elements": "^2.5.0",
+    "@webref/events": "^1.18.6",
+    "@webref/idl": "^3.66.0",
     "bcd-idl-mapper": "^3.0.0",
     "cpx2": "^8.0.0",
     "danger": "^13.0.4",
@@ -64,7 +64,7 @@
     "print-diff": "^2.0.0",
     "typescript": "^5.6.0-dev.20240806",
     "typescript-eslint": "^8",
-    "webidl2": "^24.4.1"
+    "webidl2": "^24.5.0"
   },
   "overrides": {
     "typescript@*": "$typescript"

package.json

@@ -91,7 +91,8 @@ function mapInterfaceLike(
   );
 
   if (i.iterator) {
-    const iteratorKey = i.iterator.async ? "@@asyncIterator" : "@@iterator";
+    const iteratorKey =
+      i.iterator.kind === "async_iterable" ? "@@asyncIterator" : "@@iterator";
     // BCD often doesn't have an @@iterator entry, but it does usually have an entry
     // for iterable methods such as values(). Use that as a fallback.
     // See also: https://github.com/mdn/browser-compat-data/issues/6367

src/build/bcd/mapper.ts

@@ -1082,7 +1082,7 @@ export function emitWebIdl(
 
   // Emit forEach for iterators
   function emitIteratorForEach(i: Browser.Interface) {
-    if (!i.iterator || i.iterator.async) {
+    if (!i.iterator || i.iterator.kind === "async_iterable") {
       return;
     }
     const subtype = i.iterator.type.map(convertDomTypeToTsType);
@@ -1619,7 +1619,7 @@ export function emitWebIdl(
 
   function emitSelfIterator(i: Browser.Interface) {
     if (!compilerBehavior.useIteratorObject) return;
-    const async = i.iterator?.async;
+    const async = i.iterator?.kind === "async_iterable";
     const name = getName(i);
     const iteratorBaseType = `${async ? "Async" : ""}IteratorObject`;
     const iteratorType = `${name}${async ? "Async" : ""}Iterator`;
@@ -1644,7 +1644,7 @@ export function emitWebIdl(
       case "setlike":
         return;
     }
-    const async = i.iterator?.async;
+    const async = i.iterator?.kind === "async_iterable";
     const iteratorType = async
       ? !compilerBehavior.useIteratorObject
         ? "AsyncIterableIterator"
@@ -1659,7 +1659,10 @@ export function emitWebIdl(
       name: `[Symbol.${async ? "asyncIterator" : "iterator"}]`,
       type: stringifySingleOrTupleTypes(subtypes),
     });
-    if (i.iterator?.kind === "iterable") {
+    if (
+      i.iterator?.kind === "iterable" ||
+      i.iterator?.kind === "async_iterable"
+    ) {
       if (subtypes.length === 2) {
         const [keyType, valueType] = subtypes;
         methods.push(
@@ -1718,7 +1721,7 @@ export function emitWebIdl(
     }
 
     function getIteratorSubtypes() {
-      if (i.iterator && !i.iterator.async) {
+      if (i.iterator && i.iterator.kind !== "async_iterable") {
         if (i.iterator.type.length === 1) {
           return [convertDomTypeToTsType(i.iterator.type[0])];
         }
@@ -1848,7 +1851,7 @@ export function emitWebIdl(
 
   function emitAsyncIterator(i: Browser.Interface) {
     function getAsyncIteratorSubtypes() {
-      if (i.iterator && i.iterator.kind === "iterable" && i.iterator.async) {
+      if (i.iterator && i.iterator.kind === "async_iterable") {
         if (i.iterator.type.length === 1) {
           return [convertDomTypeToTsType(i.iterator.type[0])];
         }

src/build/emitter.ts

@@ -204,9 +204,8 @@ export interface Interface {
 }
 
 export interface Iterator {
-  kind: "iterable" | "setlike" | "maplike";
+  kind: "async_iterable" | "iterable" | "setlike" | "maplike";
   readonly: boolean;
-  async: boolean;
   type: Typed[];
   param?: Param[];
   comments?: {

src/build/types.d.ts

@@ -203,16 +203,26 @@ function convertInterfaceCommon(
         addComments(method[member.name], commentMap, i.name, member.name);
       }
     } else if (
+      (member.type as string) === "async_iterable" ||
       member.type === "iterable" ||
       member.type === "maplike" ||
       member.type === "setlike"
     ) {
+      // TODO(saschanaz): @types/webidl2 doesn't support async_iterable
+      const iterableLike = member as
+        | webidl2.IterableDeclarationMemberType
+        | webidl2.MaplikeDeclarationMemberType
+        | webidl2.SetlikeDeclarationMemberType;
+      // Compatibility between `async_iterable` and `async iterable`
+      const kind =
+        iterableLike.type === "iterable" && iterableLike.async
+          ? "async_iterable"
+          : iterableLike.type;
       result.iterator = {
-        kind: member.type,
-        readonly: member.readonly,
-        async: member.async,
-        param: member.arguments.map(convertArgument),
-        type: member.idlType.map(convertIdlType),
+        kind,
+        readonly: iterableLike.readonly,
+        param: iterableLike.arguments.map(convertArgument),
+        type: iterableLike.idlType.map(convertIdlType),
       };
     }
   }