Flow: add hack to support 'Symbol.asyncIterator' (graphql#2776)

IvanGoncharov · Aug 31, 2020 · e5a2b77 · e5a2b77
1 parent f3e2954
commit e5a2b77
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Showing 5 changed files with 5 additions and 8 deletions.
diff --git a/flow-typed/core.js b/flow-typed/core.js
@@ -0,0 +1,5 @@
+// Various hacks to compensate for outdated Flow core definitions
+
+declare class Symbol extends Symbol {
+  static asyncIterator: string; // polyfill '@@asyncIterator'
+}
diff --git a/src/jsutils/__tests__/isAsyncIterable-test.js b/src/jsutils/__tests__/isAsyncIterable-test.js
@@ -6,7 +6,6 @@ import isAsyncIterable from '../isAsyncIterable';
 
 describe('isAsyncIterable', () => {
   it('should return `true` for AsyncIterable', () => {
-    // $FlowFixMe[prop-missing] Flow doesn't support Symbol.asyncIterator
     const asyncIteratable = { [Symbol.asyncIterator]: identityFunc };
     expect(isAsyncIterable(asyncIteratable)).to.equal(true);
 
@@ -45,7 +44,6 @@ describe('isAsyncIterable', () => {
     expect(isAsyncIterable(generatorFunc())).to.equal(false);
 
     const invalidAsyncIteratable = {
-      // $FlowFixMe[prop-missing] Flow doesn't support Symbol.asyncIterator
       [Symbol.asyncIterator]: { next: identityFunc },
     };
     expect(isAsyncIterable(invalidAsyncIteratable)).to.equal(false);

diff --git a/src/polyfills/symbols.js b/src/polyfills/symbols.js
@@ -6,10 +6,8 @@ export const SYMBOL_ITERATOR: string =
 // In ES2017 (or a polyfilled) environment, this will be Symbol.asyncIterator
 // istanbul ignore next (See: 'https://github.com/graphql/graphql-js/issues/2317')
 export const SYMBOL_ASYNC_ITERATOR: string =
-  // $FlowFixMe[prop-missing] Flow doesn't define `Symbol.asyncIterator` yet
   typeof Symbol === 'function' ? Symbol.asyncIterator : '@@asyncIterator';
 
 // istanbul ignore next (See: 'https://github.com/graphql/graphql-js/issues/2317')
 export const SYMBOL_TO_STRING_TAG: string =
-  // $FlowFixMe[incompatible-type] Flow doesn't define `Symbol.toStringTag` yet
   typeof Symbol === 'function' ? Symbol.toStringTag : '@@toStringTag';
diff --git a/src/subscription/__tests__/eventEmitterAsyncIterator.js b/src/subscription/__tests__/eventEmitterAsyncIterator.js
@@ -57,7 +57,6 @@ export default function eventEmitterAsyncIterator(
       emptyQueue();
       return Promise.reject(error);
     },
-    // $FlowFixMe[prop-missing] Blocked by https://github.com/facebook/flow/issues/3258
     [Symbol.asyncIterator]() {
       return this;
     },

diff --git a/src/subscription/__tests__/mapAsyncIterator-test.js b/src/subscription/__tests__/mapAsyncIterator-test.js
@@ -26,7 +26,6 @@ describe('mapAsyncIterator', () => {
     const items = [1, 2, 3];
 
     const iterator: any = {
-      // $FlowFixMe[prop-missing] Blocked by https://github.com/facebook/flow/issues/3258
       [Symbol.asyncIterator]() {
         return this;
       },
@@ -122,7 +121,6 @@ describe('mapAsyncIterator', () => {
     const items = [1, 2, 3];
 
     const iterator: any = {
-      // $FlowFixMe[prop-missing] Blocked by https://github.com/facebook/flow/issues/3258
       [Symbol.asyncIterator]() {
         return this;
       },
@@ -186,7 +184,6 @@ describe('mapAsyncIterator', () => {
     const items = [1, 2, 3];
 
     const iterator: any = {
-      // $FlowFixMe[prop-missing] Blocked by https://github.com/facebook/flow/issues/3258
       [Symbol.asyncIterator]() {
         return this;
       },