enable promise/prefer-await-to-then

leads to one less tick in `executeStreamField` in the branch where completion of a non-promise yields a promise.

Author: yaacovCR

.eslintrc.yml

@@ -196,7 +196,7 @@ rules:
   promise/no-return-wrap: error
   promise/param-names: off
   promise/prefer-await-to-callbacks: off
-  promise/prefer-await-to-then: off
+  promise/prefer-await-to-then: error
   promise/valid-params: error
 
   ##############################################################################

src/__testUtils__/__tests__/resolveOnNextTick-test.ts

@@ -7,12 +7,13 @@ describe('resolveOnNextTick', () => {
   it('resolves promise on the next tick', async () => {
     const output = [];
 
-    const promise1 = resolveOnNextTick().then(() => {
-      output.push('second');
-    });
-    const promise2 = resolveOnNextTick().then(() => {
-      output.push('third');
-    });
+    async function outputOnNextTick(message: string) {
+      await resolveOnNextTick();
+      output.push(message);
+    }
+
+    const promise1 = outputOnNextTick('second');
+    const promise2 = outputOnNextTick('third');
     output.push('first');
 
     await Promise.all([promise1, promise2]);

src/__testUtils__/expectEqualPromisesOrValues.ts

@@ -5,13 +5,18 @@ import type { PromiseOrValue } from '../jsutils/PromiseOrValue.js';
 
 import { expectMatchingValues } from './expectMatchingValues.js';
 
+async function expectMatchingPromises<T>(items: Promise<ReadonlyArray<T>>) {
+  const values = await items;
+  return expectMatchingValues(values);
+}
+
 export function expectEqualPromisesOrValues<T>(
   items: ReadonlyArray<PromiseOrValue<T>>,
 ): PromiseOrValue<T> {
   const [firstItem, ...remainingItems] = items;
   if (isPromise(firstItem)) {
     if (remainingItems.every(isPromise)) {
-      return Promise.all(items).then(expectMatchingValues);
+      return expectMatchingPromises(Promise.all(items));
     }
   } else if (remainingItems.every((item) => !isPromise(item))) {
     return expectMatchingValues(items);

src/execution/__tests__/simplePubSub-test.ts

@@ -22,9 +22,13 @@ describe('SimplePubSub', () => {
       value: 'Banana',
     });
 
+    async function getNextItem(i: AsyncIterator<unknown>) {
+      return i.next();
+    }
+
     // Read ahead
-    const i3 = iterator.next().then((x) => x);
-    const i4 = iterator.next().then((x) => x);
+    const i3 = getNextItem(iterator);
+    const i4 = getNextItem(iterator);
 
     // Publish
     expect(pubsub.emit('Coconut')).to.equal(true);
@@ -35,7 +39,7 @@ describe('SimplePubSub', () => {
     expect(await i3).to.deep.equal({ done: false, value: 'Coconut' });
 
     // Read ahead
-    const i5 = iterator.next().then((x) => x);
+    const i5 = getNextItem(iterator);
 
     // Terminate queue
     await iterator.return();

src/execution/__tests__/stream-test.ts

@@ -984,11 +984,6 @@ describe('Execute: stream directive', () => {
               },
             ],
           },
-        ],
-        hasNext: true,
-      },
-      {
-        incremental: [
           {
             items: [{ nonNullName: 'Han' }],
             path: ['friendList', 2],