feat: Wait for all handled requests to resolve via .flush() (#75)

Author: offirgolan

docs/api.md

@@ -251,3 +251,17 @@ __Example__
 ```js
 polly.disconnect();
 ```
+
+### flush
+
+Returns a Promise that resolves once all requests handled by Polly have resolved.
+
+| Param | Type | Description |
+|  ---  | ---  |     ---     |
+| Returns | `Promise` |   |
+
+__Example__
+
+```js
+await polly.flush();
+```

package.json

@@ -20,14 +20,16 @@
     "clean": "lerna run clean --parallel",
     "bootstrap": "lerna bootstrap",
     "format": "lerna run format",
-    "lint": "lerna exec --bail=false -- yarn run lint",
+    "lint": "lerna exec --bail=false --stream --no-prefix -- yarn run lint",
     "pretest": "yarn server:build",
     "pretest:ci": "yarn pretest",
     "test": "testem",
     "test:ci": "testem ci",
     "test:build": "lerna run test:build --parallel",
     "test:clean": "rimraf packages/@pollyjs/*/build",
-    "test:ember": "lerna run test --scope=@pollyjs/ember",
+    "test:node": "mocha --opts tests/mocha.opts",
+    "test:jest": "jest",
+    "test:ember": "lerna run test --stream --no-prefix --scope=@pollyjs/ember",
     "server:build": "yarn build --scope=@pollyjs/node-server --scope=@pollyjs/utils",
     "docs:serve": "docsify serve ./docs",
     "docs:publish": "gh-pages --dist docs --dotfiles --message 'chore: Publish docs'",

packages/@pollyjs/adapter-puppeteer/src/index.js

@@ -1,6 +1,7 @@
 import Adapter from '@pollyjs/adapter';
 
 const LISTENERS = Symbol();
+const POLLY_REQUEST = Symbol();
 const PASSTHROUGH_PROMISE = Symbol();
 const PASSTHROUGH_PROMISES = Symbol();
 const PASSTHROUGH_REQ_ID_HEADER = 'x-pollyjs-passthrough-request-id';
@@ -73,24 +74,68 @@ export default class PuppeteerAdapter extends Adapter {
         const request = response.request();
 
         // Resolve the passthrough promise with the response if it exists
-        request[PASSTHROUGH_PROMISE] &&
+        if (request[PASSTHROUGH_PROMISE]) {
           request[PASSTHROUGH_PROMISE].resolve(response);
-
-        delete request[PASSTHROUGH_PROMISE];
+          delete request[PASSTHROUGH_PROMISE];
+        }
+      },
+      requestfinished: request => {
+        // Resolve the deferred pollyRequest promise if it exists
+        if (request[POLLY_REQUEST]) {
+          request[POLLY_REQUEST].promise.resolve(request.response());
+          delete request[POLLY_REQUEST];
+        }
       },
       requestfailed: request => {
         // Reject the passthrough promise with the error object if it exists
-        request[PASSTHROUGH_PROMISE] &&
+        if (request[PASSTHROUGH_PROMISE]) {
           request[PASSTHROUGH_PROMISE].reject(request.failure());
+          delete request[PASSTHROUGH_PROMISE];
+        }
 
-        delete request[PASSTHROUGH_PROMISE];
+        // Reject the deferred pollyRequest promise with the error object if it exists
+        if (request[POLLY_REQUEST]) {
+          request[POLLY_REQUEST].promise.reject(request.failure());
+          delete request[POLLY_REQUEST];
+        }
       },
       close: () => this[LISTENERS].delete(page)
     });
 
     this._callListenersWith('prependListener', page);
   }
 
+  onRequest(pollyRequest) {
+    const [request] = pollyRequest.requestArguments;
+
+    /*
+      Create an access point to the `pollyRequest` so it can be accessed from
+      the emitted page events
+    */
+    request[POLLY_REQUEST] = pollyRequest;
+  }
+
+  /**
+   * Override the onRequestFinished logic as it doesn't apply to this adapter.
+   * Instead, that logic is re-implemented via the `requestfinished` page
+   * event.
+   *
+   * @override
+   */
+  onRequestFinished() {}
+
+  /**
+   * Abort the request on failure. The parent `onRequestFailed` has been
+   * re-implemented via the `requestfailed` page event.
+   *
+   * @override
+   */
+  async onRequestFailed(pollyRequest) {
+    const [request] = pollyRequest.requestArguments;
+
+    await request.abort();
+  }
+
   async onRecord(pollyRequest) {
     await this.passthroughRequest(pollyRequest);
     await this.persister.recordRequest(pollyRequest);

packages/@pollyjs/adapter-puppeteer/tests/integration/adapter-test.js

@@ -64,4 +64,40 @@ describe('Integration | Puppeteer Adapter', function() {
   setupPolly.afterEach();
 
   adapterTests();
+
+  it('should have resolved requests after flushing', async function() {
+    // Timeout after 500ms since we could have a hanging while loop
+    this.timeout(500);
+
+    const { server } = this.polly;
+    const requests = [];
+    const resolved = [];
+    let i = 1;
+
+    server
+      .get(this.recordUrl())
+      .intercept(async (req, res) => {
+        await server.timeout(5);
+        res.sendStatus(200);
+      })
+      .on('request', req => requests.push(req));
+
+    this.page.on('requestfinished', () => resolved.push(i++));
+
+    this.fetchRecord();
+    this.fetchRecord();
+    this.fetchRecord();
+
+    // Since it takes time for Puppeteer to execute the request in the browser's
+    // context, we have to wait until the requests have been made.
+    while (requests.length !== 3) {
+      await server.timeout(5);
+    }
+
+    await this.polly.flush();
+
+    expect(requests).to.have.lengthOf(3);
+    requests.forEach(request => expect(request.didRespond).to.be.true);
+    expect(resolved).to.have.members([1, 2, 3]);
+  });
 });

packages/@pollyjs/adapter/src/index.js

@@ -87,17 +87,28 @@ export default class Adapter {
     }
   }
 
-  handleRequest() {
-    return this[REQUEST_HANDLER](...arguments);
+  async handleRequest(request) {
+    const pollyRequest = this.polly.registerRequest(request);
+
+    await pollyRequest.setup();
+    await this.onRequest(pollyRequest);
+
+    try {
+      const result = await this[REQUEST_HANDLER](pollyRequest);
+
+      await this.onRequestFinished(pollyRequest, result);
+
+      return result;
+    } catch (error) {
+      await this.onRequestFailed(pollyRequest, error);
+      throw error;
+    }
   }
 
-  async [REQUEST_HANDLER](request) {
+  async [REQUEST_HANDLER](pollyRequest) {
     const { mode } = this.polly;
-    const pollyRequest = this.polly.registerRequest(request);
     let interceptor;
 
-    await pollyRequest.setup();
-
     if (pollyRequest.shouldIntercept) {
       interceptor = new Interceptor();
       const response = await this.intercept(pollyRequest, interceptor);
@@ -203,6 +214,7 @@ export default class Adapter {
     );
   }
 
+  /* Required Hooks */
   onConnect() {
     this.assert('Must implement the `onConnect` hook.', false);
   }
@@ -211,19 +223,60 @@ export default class Adapter {
     this.assert('Must implement the `onDisconnect` hook.', false);
   }
 
+  /**
+   * @param {PollyRequest} pollyRequest
+   * @returns {*}
+   */
   onRecord() {
     this.assert('Must implement the `onRecord` hook.', false);
   }
 
+  /**
+   * @param {PollyRequest} pollyRequest
+   * @param {Object} normalizedResponse The normalized response generated from the recording entry
+   * @param {Object} recordingEntry The entire recording entry
+   * @returns {*}
+   */
   onReplay() {
     this.assert('Must implement the `onReplay` hook.', false);
   }
 
+  /**
+   * @param {PollyRequest} pollyRequest
+   * @param {PollyResponse} response
+   * @returns {*}
+   */
   onIntercept() {
     this.assert('Must implement the `onIntercept` hook.', false);
   }
 
+  /**
+   * @param {PollyRequest} pollyRequest
+   * @returns {*}
+   */
   onPassthrough() {
     this.assert('Must implement the `onPassthrough` hook.', false);
   }
+
+  /* Other Hooks */
+  /**
+   * @param {PollyRequest} pollyRequest
+   */
+  onRequest() {}
+
+  /**
+   * @param {PollyRequest} pollyRequest
+   * @param {*} result The returned result value from the request handler
+   */
+  onRequestFinished(pollyRequest, result) {
+    pollyRequest.promise.resolve(result);
+  }
+
+  /**
+   * @param {PollyRequest} pollyRequest
+   * @param {Error} error
+   */
+  onRequestFailed(pollyRequest, error) {
+    pollyRequest.promise.reject(error);
+  }
 }

packages/@pollyjs/core/src/-private/request.js

@@ -5,6 +5,7 @@ import PollyResponse from './response';
 import NormalizeRequest from '../utils/normalize-request';
 import parseUrl from '../utils/parse-url';
 import serializeRequestBody from '../utils/serialize-request-body';
+import DeferredPromise from '../utils/deferred-promise';
 import isAbsoluteUrl from 'is-absolute-url';
 import { assert, timestamp } from '@pollyjs/utils';
 import HTTPBase from './http-base';
@@ -29,6 +30,7 @@ export default class PollyRequest extends HTTPBase {
     this.recordingName = polly.recordingName;
     this.recordingId = polly.recordingId;
     this.requestArguments = freeze(request.requestArguments || []);
+    this.promise = new DeferredPromise();
     this[POLLY] = polly;
 
     /*
@@ -54,11 +56,7 @@ export default class PollyRequest extends HTTPBase {
   get absoluteUrl() {
     const { url } = this;
 
-    if (!isAbsoluteUrl(url)) {
-      return new URL(url).href;
-    }
-
-    return url;
+    return isAbsoluteUrl(url) ? url : new URL(url).href;
   }
 
   get protocol() {

packages/@pollyjs/core/src/polly.js

@@ -234,6 +234,16 @@ export default class Polly {
     }
   }
 
+  async flush() {
+    const NOOP = () => {};
+
+    await Promise.all(
+      // The NOOP is there to handle both a resolved and rejected promise
+      // to ensure the promise resolves regardless of the outcome.
+      this._requests.map(r => Promise.resolve(r.promise).then(NOOP, NOOP))
+    );
+  }
+
   /**
    * @param {String|Function} nameOrFactory
    * @public

packages/@pollyjs/core/src/utils/deferred-promise.js

@@ -0,0 +1,16 @@
+/**
+ * Create a deferred promise with `resolve` and `reject` methods.
+ */
+export default class DeferredPromise extends Promise {
+  constructor() {
+    let resolve, reject;
+
+    super((_resolve, _reject) => {
+      resolve = _resolve;
+      reject = _reject;
+    });
+
+    this.resolve = resolve;
+    this.reject = reject;
+  }
+}

packages/@pollyjs/core/tests/unit/utils/deferred-promise-test.js

@@ -0,0 +1,29 @@
+import DeferredPromise from '../../../src/utils/deferred-promise';
+
+describe('Unit | Utils | DeferredPromise', function() {
+  it('should exist', function() {
+    expect(DeferredPromise).to.be.a('function');
+    expect(new DeferredPromise().resolve).to.be.a('function');
+    expect(new DeferredPromise().reject).to.be.a('function');
+  });
+
+  it('should resolve when calling .resolve()', async function() {
+    const promise = new DeferredPromise();
+
+    promise.resolve(42);
+    expect(await promise).to.equal(42);
+  });
+
+  it('should reject when calling .reject()', async function() {
+    const promise = new DeferredPromise();
+
+    promise.reject(new Error('42'));
+
+    try {
+      await promise;
+    } catch (error) {
+      expect(error).to.be.an('error');
+      expect(error.message).to.equal('42');
+    }
+  });
+});

testem.js

@@ -15,7 +15,7 @@ module.exports = {
     './tests/*',
     './tests/!(recordings)/**/*',
     './packages/@pollyjs/*/src/**/*',
-    './packages/@pollyjs/*/tests/*/*'
+    './packages/@pollyjs/*/tests/**/*'
   ],
   serve_files: ['./packages/@pollyjs/*/build/browser/*.js'],
   browser_args: {
@@ -33,12 +33,11 @@ module.exports = {
   middleware: [attachMiddleware],
   launchers: {
     Node: {
-      command:
-        'mocha ./packages/@pollyjs/*/build/node/*.js --ui bdd --reporter tap --require tests/node-setup.js',
+      command: 'yarn test:node --reporter tap',
       protocol: 'tap'
     },
     Jest: {
-      command: 'jest',
+      command: 'yarn test:jest',
       protocol: 'tap'
     },
     Ember: {