Wait for an executor

src/main/ExecutorImpl.ts

@@ -62,11 +62,8 @@ export class ExecutorImpl<Value = any> implements Executor {
     return this.isFulfilled ? this.value! : defaultValue;
   }
 
-  then<Result1 = Value, Result2 = never>(
-    onFulfilled?: ((value: Value) => PromiseLike<Result1> | Result1) | null,
-    onRejected?: ((reason: any) => PromiseLike<Result2> | Result2) | null
-  ): Promise<Result1 | Result2> {
-    return new Promise<Value>((resolve, reject) => {
+  toPromise(): AbortablePromise<Value> {
+    return new AbortablePromise((resolve, reject, signal) => {
       if (this.isSettled && !this.isPending) {
         resolve(this.get());
         return;
@@ -88,7 +85,9 @@ export class ExecutorImpl<Value = any> implements Executor {
           }
         }
       });
-    }).then(onFulfilled, onRejected);
+
+      signal.addEventListener('abort', unsubscribe);
+    });
   }
 
   execute(task: ExecutorTask<Value>): AbortablePromise<Value> {

src/main/ExecutorManager.ts

@@ -1,4 +1,4 @@
-import { PubSub } from 'parallel-universe';
+import { AbortablePromise, PubSub } from 'parallel-universe';
 import { ExecutorImpl } from './ExecutorImpl';
 import type { Executor, ExecutorEvent, ExecutorPlugin, ExecutorTask } from './types';
 
@@ -70,6 +70,31 @@ export class ExecutorManager implements Iterable<Executor> {
     return executor;
   }
 
+  /**
+   * Resolves with the existing executor or waits for an executor to be created.
+   *
+   * @param key The executor key to wait for.
+   */
+  waitFor(key: string): AbortablePromise<Executor> {
+    return new AbortablePromise((resolve, _reject, signal) => {
+      const executor = this._executors.get(key);
+
+      if (executor !== undefined) {
+        resolve(executor);
+        return;
+      }
+
+      const unsubscribe = this.subscribe(event => {
+        if (event.target.key === key && event.type === 'configured') {
+          unsubscribe();
+          resolve(event.target);
+        }
+      });
+
+      signal.addEventListener('abort', unsubscribe);
+    });
+  }
+
   /**
    * Deletes the non-{@link Executor.isActive active} executor from the manager.
    *

src/main/types.ts

@@ -134,7 +134,7 @@ export type ExecutorTask<Value = any> = (signal: AbortSignal, executor: Executor
  *
  * @template Value The value stored by the executor.
  */
-export interface Executor<Value = any> extends PromiseLike<Value> {
+export interface Executor<Value = any> {
   /**
    * The key of this executor, unique in scope of the {@link manager}.
    */
@@ -210,22 +210,11 @@ export interface Executor<Value = any> extends PromiseLike<Value> {
   getOrDefault(defaultValue: Value): Value;
 
   /**
-   * Attaches callbacks for the fulfillment and/or rejection of the executor.
-   *
    * For a non-{@link isPending pending} and {@link isSettled settled} executor, the promise is resolved with the
    * available {@link value}, or rejected with the available {@link reason}. Otherwise, the promise waits for the
    * executor to become settled and then settles as well.
-   *
-   * @param onFulfilled The callback to execute when the executor is fulfilled.
-   * @param onRejected The callback to execute when the executor is rejected.
-   * @returns A promise for the completion of whichever callback is executed.
-   * @template Result1 The result of the fulfillment callback.
-   * @template Result2 The result of the rejection callback.
    */
-  then<Result1 = Value, Result2 = never>(
-    onFulfilled?: ((value: Value) => PromiseLike<Result1> | Result1) | null,
-    onRejected?: ((reason: any) => PromiseLike<Result2> | Result2) | null
-  ): Promise<Result1 | Result2>;
+  toPromise(): AbortablePromise<Value>;
 
   /**
    * Executes a task and populates the executor with the returned result.

src/main/useExecutorSuspense.ts

@@ -24,10 +24,10 @@ export function useExecutorSuspense(executors: Executor | Executor[]) {
     const promises = executors.reduce(reducePending, null);
 
     if (promises !== null) {
-      throw Promise.allSettled(promises).then(noop, noop);
+      throw Promise.all(promises).then(noop, noop);
     }
   } else if (executors.isPending) {
-    throw executors.then(noop, noop);
+    throw executors.toPromise().then(noop, noop);
   }
 
   return executors;
@@ -36,10 +36,9 @@ export function useExecutorSuspense(executors: Executor | Executor[]) {
 function reducePending(promises: PromiseLike<unknown>[] | null, executor: Executor): PromiseLike<unknown>[] | null {
   if (executor.isPending) {
     if (promises === null) {
-      promises = [executor];
-    } else {
-      promises.push(executor);
+      promises = [];
     }
+    promises.push(executor.toPromise().then(noop, noop));
   }
   return promises;
 }

src/test/ExecutorImpl.test.ts

@@ -616,55 +616,29 @@ describe('ExecutorImpl', () => {
     });
   });
 
-  describe('then', () => {
+  describe('toPromise', () => {
     test('resolves with the value if an executor is fulfilled', async () => {
       executor.resolve('aaa');
 
-      await expect(executor.then()).resolves.toBe('aaa');
+      await expect(executor.toPromise()).resolves.toBe('aaa');
     });
 
     test('rejects with the reason if an executor is fulfilled', async () => {
       executor.reject(expectedReason);
 
-      await expect(executor.then()).rejects.toBe(expectedReason);
-    });
-
-    test('calls onFulfilled callback', async () => {
-      const onFulfilledMock = jest.fn(_value => 'bbb');
-      const onRejectedMock = jest.fn();
-
-      executor.resolve('aaa');
-
-      await expect(executor.then(onFulfilledMock, onRejectedMock)).resolves.toBe('bbb');
-
-      expect(onFulfilledMock).toHaveBeenCalledTimes(1);
-      expect(onFulfilledMock.mock.calls[0][0]).toBe('aaa');
-      expect(onRejectedMock).toHaveBeenCalledTimes(0);
-    });
-
-    test('calls onRejected callback', async () => {
-      const onFulfilledMock = jest.fn();
-      const onRejectedMock = jest.fn(_reason => 'aaa');
-
-      executor.reject(expectedReason);
-
-      await expect(executor.then(onFulfilledMock, onRejectedMock)).resolves.toBe('aaa');
-
-      expect(onFulfilledMock).toHaveBeenCalledTimes(0);
-      expect(onRejectedMock).toHaveBeenCalledTimes(1);
-      expect(onRejectedMock.mock.calls[0][0]).toBe(expectedReason);
+      await expect(executor.toPromise()).rejects.toBe(expectedReason);
     });
 
     test('waits for the executor to be fulfilled', async () => {
-      const promise = executor.then();
+      const promise = executor.toPromise();
 
       executor.resolve('aaa');
 
       await expect(promise).resolves.toBe('aaa');
     });
 
     test('waits for the executor to be rejected', async () => {
-      const promise = executor.then();
+      const promise = executor.toPromise();
 
       executor.reject(expectedReason);
 
@@ -675,7 +649,7 @@ describe('ExecutorImpl', () => {
       executor.resolve('aaa');
       executor.execute(() => 'bbb').catch(noop);
 
-      const promise = executor.then();
+      const promise = executor.toPromise();
 
       executor.execute(() => 'ccc');
 

src/test/ExecutorManager.test.ts

@@ -83,7 +83,7 @@ describe('ExecutorManager', () => {
       expect(listenerMock).toHaveBeenNthCalledWith(1, { type: 'configured', target: executor });
       expect(listenerMock).toHaveBeenNthCalledWith(2, { type: 'pending', target: executor });
 
-      await expect(executor.then()).resolves.toBe(111);
+      await expect(executor.toPromise()).resolves.toBe(111);
 
       expect(executor.isPending).toBe(false);
       expect(executor.isFulfilled).toBe(true);
@@ -136,7 +136,7 @@ describe('ExecutorManager', () => {
       expect(listenerMock).toHaveBeenCalledTimes(1);
       expect(listenerMock).toHaveBeenNthCalledWith(1, { type: 'configured', target: executor });
 
-      await executor;
+      await executor.toPromise();
 
       expect(executor.value).toBe(222);
 
@@ -172,6 +172,19 @@ describe('ExecutorManager', () => {
     });
   });
 
+  describe('waitFor', () => {
+    test('waits for an executor', async () => {
+      await expect(manager.waitFor('aaa')).resolves.toBe(manager.getOrCreate('aaa'));
+    });
+
+    test('resolves with the existing executor', async () => {
+      const executor = manager.getOrCreate('aaa');
+      const executorPromise = manager.waitFor('aaa');
+
+      await expect(executorPromise).resolves.toBe(executor);
+    });
+  });
+
   describe('dispose', () => {
     test('no-op is there is no executor with the key', () => {
       expect(manager.dispose('aaa')).toBe(false);

src/test/plugin/retryFocused.test.ts

@@ -15,7 +15,7 @@ describe('retryFocused', () => {
 
     executor.activate();
 
-    await executor;
+    await executor.toPromise();
 
     expect(executor.value).toBe('aaa');
 
@@ -24,7 +24,7 @@ describe('retryFocused', () => {
     expect(executor.isPending).toBe(true);
     expect(executor.value).toBe('aaa');
 
-    await executor;
+    await executor.toPromise();
 
     expect(executor.isPending).toBe(false);
     expect(executor.value).toBe('bbb');

src/test/plugin/retryFulfilled.test.ts

@@ -22,19 +22,19 @@ describe('retryFulfilled', () => {
 
     executor.activate();
     expect(executor.isPending).toBe(true);
-    await executor;
+    await executor.toPromise();
     expect(executor.isPending).toBe(false);
 
     // Retry 1
     jest.runAllTimers();
     expect(executor.isPending).toBe(true);
-    await executor;
+    await executor.toPromise();
     expect(executor.isPending).toBe(false);
 
     // Retry 2
     jest.runAllTimers();
     expect(executor.isPending).toBe(true);
-    await executor;
+    await executor.toPromise();
     expect(executor.isPending).toBe(false);
 
     // Retry 3
@@ -50,7 +50,7 @@ describe('retryFulfilled', () => {
 
     executor.activate();
     expect(executor.isPending).toBe(true);
-    await executor;
+    await executor.toPromise();
     expect(executor.isPending).toBe(false);
 
     // Retry 1
@@ -73,7 +73,7 @@ describe('retryFulfilled', () => {
 
     executor.activate();
     expect(executor.isPending).toBe(true);
-    await executor;
+    await executor.toPromise();
     expect(executor.isPending).toBe(false);
 
     // Retry 1
@@ -96,15 +96,15 @@ describe('retryFulfilled', () => {
 
     const deactivate = executor.activate();
     expect(executor.isPending).toBe(true);
-    await executor;
+    await executor.toPromise();
     expect(executor.isPending).toBe(false);
 
     // Retry 1
     jest.runAllTimers();
     expect(executor.isPending).toBe(true);
 
     deactivate();
-    await executor;
+    await executor.toPromise();
 
     // Retry 2
     jest.runAllTimers();

src/test/plugin/retryRejected.test.ts

@@ -28,21 +28,21 @@ describe('retryRejected', () => {
     executor.activate();
     expect(executor.isPending).toBe(true);
     (executor as ExecutorImpl)._promise!.catch(noop);
-    await executor.then(noop, noop);
+    await executor.toPromise().then(noop, noop);
     expect(executor.isPending).toBe(false);
 
     // Retry 1
     jest.runAllTimers();
     expect(executor.isPending).toBe(true);
     (executor as ExecutorImpl)._promise!.catch(noop);
-    await executor.then(noop, noop);
+    await executor.toPromise().then(noop, noop);
     expect(executor.isPending).toBe(false);
 
     // Retry 2
     jest.runAllTimers();
     expect(executor.isPending).toBe(true);
     (executor as ExecutorImpl)._promise!.catch(noop);
-    await executor.then(noop, noop);
+    await executor.toPromise().then(noop, noop);
     expect(executor.isPending).toBe(false);
 
     // Retry 3
@@ -62,7 +62,7 @@ describe('retryRejected', () => {
     executor.activate();
     expect(executor.isPending).toBe(true);
     (executor as ExecutorImpl)._promise!.catch(noop);
-    await executor.then(noop, noop);
+    await executor.toPromise().then(noop, noop);
     expect(executor.isPending).toBe(false);
 
     // Retry 1
@@ -89,7 +89,7 @@ describe('retryRejected', () => {
     executor.activate();
     expect(executor.isPending).toBe(true);
     (executor as ExecutorImpl)._promise!.catch(noop);
-    await executor.then(noop, noop);
+    await executor.toPromise().then(noop, noop);
     expect(executor.isPending).toBe(false);
 
     // Retry 1
@@ -116,7 +116,7 @@ describe('retryRejected', () => {
     const deactivate = executor.activate();
     expect(executor.isPending).toBe(true);
     (executor as ExecutorImpl)._promise!.catch(noop);
-    await executor.then(noop, noop);
+    await executor.toPromise().then(noop, noop);
     expect(executor.isPending).toBe(false);
 
     // Retry 1
@@ -126,7 +126,7 @@ describe('retryRejected', () => {
     deactivate();
 
     (executor as ExecutorImpl)._promise!.catch(noop);
-    await executor.then(noop, noop);
+    await executor.toPromise().then(noop, noop);
 
     // Retry 2
     jest.runAllTimers();