tor-browser

cancel.any.js (7840B)

---

// META: global=window,worker,shadowrealm
// META: script=../resources/test-utils.js
// META: script=../resources/rs-utils.js
'use strict';

promise_test(t => {

 const randomSource = new RandomPushSource();

 let cancellationFinished = false;
 const rs = new ReadableStream({
   start(c) {
     randomSource.ondata = c.enqueue.bind(c);
     randomSource.onend = c.close.bind(c);
     randomSource.onerror = c.error.bind(c);
   },

   pull() {
     randomSource.readStart();
   },

   cancel() {
     randomSource.readStop();

     return new Promise(resolve => {
       t.step_timeout(() => {
         cancellationFinished = true;
         resolve();
       }, 1);
     });
   }
 });

 const reader = rs.getReader();

 // We call delay multiple times to avoid cancelling too early for the
 // source to enqueue at least one chunk.
 const cancel = delay(5).then(() => delay(5)).then(() => delay(5)).then(() => {
   const cancelPromise = reader.cancel();
   assert_false(cancellationFinished, 'cancellation in source should happen later');
   return cancelPromise;
 });

 return readableStreamToArray(rs, reader).then(chunks => {
   assert_greater_than(chunks.length, 0, 'at least one chunk should be read');
   for (let i = 0; i < chunks.length; i++) {
     assert_equals(chunks[i].length, 128, 'chunk ' + i + ' should have 128 bytes');
   }
   return cancel;
 }).then(() => {
   assert_true(cancellationFinished, 'it returns a promise that is fulfilled when the cancellation finishes');
 });

}, 'ReadableStream cancellation: integration test on an infinite stream derived from a random push source');

test(() => {

 let recordedReason;
 const rs = new ReadableStream({
   cancel(reason) {
     recordedReason = reason;
   }
 });

 const passedReason = new Error('Sorry, it just wasn\'t meant to be.');
 rs.cancel(passedReason);

 assert_equals(recordedReason, passedReason,
   'the error passed to the underlying source\'s cancel method should equal the one passed to the stream\'s cancel');

}, 'ReadableStream cancellation: cancel(reason) should pass through the given reason to the underlying source');

promise_test(() => {

 const rs = new ReadableStream({
   start(c) {
     c.enqueue('a');
     c.close();
   },
   cancel() {
     assert_unreached('underlying source cancel() should not have been called');
   }
 });

 const reader = rs.getReader();

 return rs.cancel().then(() => {
   assert_unreached('cancel() should be rejected');
 }, e => {
   assert_equals(e.name, 'TypeError', 'cancel() should be rejected with a TypeError');
 }).then(() => {
   return reader.read();
 }).then(result => {
   assert_object_equals(result, { value: 'a', done: false }, 'read() should still work after the attempted cancel');
   return reader.closed;
 });

}, 'ReadableStream cancellation: cancel() on a locked stream should fail and not call the underlying source cancel');

promise_test(() => {

 let cancelReceived = false;
 const cancelReason = new Error('I am tired of this stream, I prefer to cancel it');
 const rs = new ReadableStream({
   cancel(reason) {
     cancelReceived = true;
     assert_equals(reason, cancelReason, 'cancellation reason given to the underlying source should be equal to the one passed');
   }
 });

 return rs.cancel(cancelReason).then(() => {
   assert_true(cancelReceived);
 });

}, 'ReadableStream cancellation: should fulfill promise when cancel callback went fine');

promise_test(() => {

 const rs = new ReadableStream({
   cancel() {
     return 'Hello';
   }
 });

 return rs.cancel().then(v => {
   assert_equals(v, undefined, 'cancel() return value should be fulfilled with undefined');
 });

}, 'ReadableStream cancellation: returning a value from the underlying source\'s cancel should not affect the fulfillment value of the promise returned by the stream\'s cancel');

promise_test(() => {

 const thrownError = new Error('test');
 let cancelCalled = false;

 const rs = new ReadableStream({
   cancel() {
     cancelCalled = true;
     throw thrownError;
   }
 });

 return rs.cancel('test').then(() => {
   assert_unreached('cancel should reject');
 }, e => {
   assert_true(cancelCalled);
   assert_equals(e, thrownError);
 });

}, 'ReadableStream cancellation: should reject promise when cancel callback raises an exception');

promise_test(() => {

 const cancelReason = new Error('test');

 const rs = new ReadableStream({
   cancel(error) {
     assert_equals(error, cancelReason);
     return delay(1);
   }
 });

 return rs.cancel(cancelReason);

}, 'ReadableStream cancellation: if the underlying source\'s cancel method returns a promise, the promise returned by the stream\'s cancel should fulfill when that one does (1)');

promise_test(t => {

 let resolveSourceCancelPromise;
 let sourceCancelPromiseHasFulfilled = false;

 const rs = new ReadableStream({
   cancel() {
     const sourceCancelPromise = new Promise(resolve => resolveSourceCancelPromise = resolve);

     sourceCancelPromise.then(() => {
       sourceCancelPromiseHasFulfilled = true;
     });

     return sourceCancelPromise;
   }
 });

 t.step_timeout(() => resolveSourceCancelPromise('Hello'), 1);

 return rs.cancel().then(value => {
   assert_true(sourceCancelPromiseHasFulfilled, 'cancel() return value should be fulfilled only after the promise returned by the underlying source\'s cancel');
   assert_equals(value, undefined, 'cancel() return value should be fulfilled with undefined');
 });

}, 'ReadableStream cancellation: if the underlying source\'s cancel method returns a promise, the promise returned by the stream\'s cancel should fulfill when that one does (2)');

promise_test(t => {

 let rejectSourceCancelPromise;
 let sourceCancelPromiseHasRejected = false;

 const rs = new ReadableStream({
   cancel() {
     const sourceCancelPromise = new Promise((resolve, reject) => rejectSourceCancelPromise = reject);

     sourceCancelPromise.catch(() => {
       sourceCancelPromiseHasRejected = true;
     });

     return sourceCancelPromise;
   }
 });

 const errorInCancel = new Error('Sorry, it just wasn\'t meant to be.');

 t.step_timeout(() => rejectSourceCancelPromise(errorInCancel), 1);

 return rs.cancel().then(() => {
   assert_unreached('cancel() return value should be rejected');
 }, r => {
   assert_true(sourceCancelPromiseHasRejected, 'cancel() return value should be rejected only after the promise returned by the underlying source\'s cancel');
   assert_equals(r, errorInCancel, 'cancel() return value should be rejected with the underlying source\'s rejection reason');
 });

}, 'ReadableStream cancellation: if the underlying source\'s cancel method returns a promise, the promise returned by the stream\'s cancel should reject when that one does');

promise_test(() => {

 const rs = new ReadableStream({
   start() {
     return new Promise(() => {});
   },
   pull() {
     assert_unreached('pull should not have been called');
   }
 });

 return Promise.all([rs.cancel(), rs.getReader().closed]);

}, 'ReadableStream cancellation: cancelling before start finishes should prevent pull() from being called');

promise_test(async () => {

 const events = [];

 const pendingPromise = new Promise(() => {});

 const rs = new ReadableStream({
   pull() {
     events.push('pull');
     return pendingPromise;
   },
   cancel() {
     events.push('cancel');
   }
 });

 const reader = rs.getReader();
 reader.read().catch(() => {}); // No await.
 await delay(0);
 await Promise.all([reader.cancel(), reader.closed]);

 assert_array_equals(events, ['pull', 'cancel'], 'cancel should have been called');

}, 'ReadableStream cancellation: underlyingSource.cancel() should called, even with pending pull');