Implement author-constructible ReadableStream using V8 extras

third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/readable-stream-reader.js

Index: third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/readable-stream-reader.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/readable-stream-reader.js b/third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/readable-stream-reader.js
new file mode 100644
index 0000000000000000000000000000000000000000..1d5bc13004f8a357fc5e82522f3bd309f1311b9a
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/readable-stream-reader.js
@@ -0,0 +1,485 @@
+'use strict';
+
+if (self.importScripts) {
+  self.importScripts('../resources/rs-utils.js');
+  self.importScripts('/resources/testharness.js');
+}
+
+let ReadableStreamReader;
+
+test(() => {
+
+  // It's not exposed globally, but we test a few of its properties here.
+  ReadableStreamReader = (new ReadableStream()).getReader().constructor;
+
+}, 'Can get the ReadableStreamReader constructor indirectly');
+
+test(() => {
+
+  assert_throws(new TypeError(), () => new ReadableStreamReader('potato'));
+  assert_throws(new TypeError(), () => new ReadableStreamReader({}));
+  assert_throws(new TypeError(), () => new ReadableStreamReader());
+
+}, 'ReadableStreamReader constructor should get a ReadableStream object as argument');
+
+test(() => {
+
+  const methods = ['cancel', 'constructor', 'read', 'releaseLock'];
+  const properties = methods.concat(['closed']).sort();
+
+  const rsReader = new ReadableStreamReader(new ReadableStream());
+  const proto = Object.getPrototypeOf(rsReader);
+
+  assert_array_equals(Object.getOwnPropertyNames(proto).sort(), properties);
+
+  for (const m of methods) {
+    const propDesc = Object.getOwnPropertyDescriptor(proto, m);
+    assert_equals(propDesc.enumerable, false, 'method should be non-enumerable');
+    assert_equals(propDesc.configurable, true, 'method should be configurable');
+    assert_equals(propDesc.writable, true, 'method should be writable');
+    assert_equals(typeof rsReader[m], 'function', 'should have be a method');
+  }
+
+  const closedPropDesc = Object.getOwnPropertyDescriptor(proto, 'closed');
+  assert_equals(closedPropDesc.enumerable, false, 'closed should be non-enumerable');
+  assert_equals(closedPropDesc.configurable, true, 'closed should be configurable');
+  assert_not_equals(closedPropDesc.get, undefined, 'closed should have a getter');
+  assert_equals(closedPropDesc.set, undefined, 'closed should not have a setter');
+
+  assert_equals(rsReader.cancel.length, 1, 'cancel has 1 parameter');
+  assert_not_equals(rsReader.closed, undefined, 'has a non-undefined closed property');
+  assert_equals(typeof rsReader.closed.then, 'function', 'closed property is thenable');
+  assert_equals(typeof rsReader.constructor, 'function', 'has a constructor method');
+  assert_equals(rsReader.constructor.length, 1, 'constructor has 1 parameter');
+  assert_equals(typeof rsReader.read, 'function', 'has a getReader method');
+  assert_equals(rsReader.read.length, 0, 'read has no parameters');
+  assert_equals(typeof rsReader.releaseLock, 'function', 'has a releaseLock method');
+  assert_equals(rsReader.releaseLock.length, 0, 'releaseLock has no parameters');
+
+}, 'ReadableStreamReader instances should have the correct list of properties');
+
+test(() => {
+
+  const rsReader = new ReadableStreamReader(new ReadableStream());
+  assert_equals(rsReader.closed, rsReader.closed, 'closed should return the same promise');
+
+}, 'ReadableStreamReader closed should always return the same promise object');
+
+test(() => {
+
+  const rs = new ReadableStream();
+  new ReadableStreamReader(rs); // Constructing directly the first time should be fine.
+  assert_throws(new TypeError(), () => new ReadableStreamReader(rs),
+                'constructing directly the second time should fail');
+
+}, 'Constructing a ReadableStreamReader directly should fail if the stream is already locked (via direct ' +
+   'construction)');
+
+test(() => {
+
+  const rs = new ReadableStream();
+  new ReadableStreamReader(rs); // Constructing directly should be fine.
+  assert_throws(new TypeError(), () => rs.getReader(), 'getReader() should fail');
+
+}, 'Getting a ReadableStreamReader via getReader should fail if the stream is already locked (via direct ' +
+   'construction)');
+
+test(() => {
+
+  const rs = new ReadableStream();
+  rs.getReader(); // getReader() should be fine.
+  assert_throws(new TypeError(), () => new ReadableStreamReader(rs), 'constructing directly should fail');
+
+}, 'Constructing a ReadableStreamReader directly should fail if the stream is already locked (via getReader)');
+
+test(() => {
+
+  const rs = new ReadableStream();
+  rs.getReader(); // getReader() should be fine.
+  assert_throws(new TypeError(), () => rs.getReader(), 'getReader() should fail');
+
+}, 'Getting a ReadableStreamReader via getReader should fail if the stream is already locked (via getReader)');
+
+test(() => {
+
+  const rs = new ReadableStream({
+    start(c) {
+      c.close();
+    }
+  });
+
+  new ReadableStreamReader(rs); // Constructing directly should not throw.
+
+}, 'Constructing a ReadableStreamReader directly should be OK if the stream is closed');
+
+test(() => {
+
+  const theError = new Error('don\'t say i didn\'t warn ya');
+  const rs = new ReadableStream({
+    start(c) {
+      c.error(theError);
+    }
+  });
+
+  new ReadableStreamReader(rs); // Constructing directly should not throw.
+
+}, 'Constructing a ReadableStreamReader directly should be OK if the stream is errored');
+
+promise_test(() => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+  const reader = rs.getReader();
+
+  const promise = reader.read().then(result => {
+    assert_object_equals(result, { value: 'a', done: false }, 'read() should fulfill with the enqueued chunk');
+  });
+
+  controller.enqueue('a');
+  return promise;
+
+}, 'Reading from a reader for an empty stream will wait until a chunk is available');
+
+promise_test(() => {
+
+  let cancelCalled = false;
+  const passedReason = new Error('it wasn\'t the right time, sorry');
+  const rs = new ReadableStream({
+    cancel(reason) {
+      assert_true(rs.locked, 'the stream should still be locked');
+      assert_throws(new TypeError(), () => rs.getReader(), 'should not be able to get another reader');
+      assert_equals(reason, passedReason, 'the cancellation reason is passed through to the underlying source');
+      cancelCalled = true;
+    }
+  });
+
+  const reader = rs.getReader();
+  return reader.cancel(passedReason).then(() => assert_true(cancelCalled));
+
+}, 'cancel() on a reader does not release the reader');
+
+promise_test(() => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const reader = rs.getReader();
+  const promise = reader.closed;
+
+  controller.close();
+  return promise;
+
+}, 'closed should be fulfilled after stream is closed (.closed access before acquiring)');
+
+promise_test(t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const reader1 = rs.getReader();
+
+  reader1.releaseLock();
+
+  const reader2 = rs.getReader();
+  controller.close();
+
+  return Promise.all([
+    promise_rejects(t, new TypeError(), reader1.closed),
+    reader2.closed
+  ]);
+
+}, 'closed should be rejected after reader releases its lock (multiple stream locks)');
+
+promise_test(() => {
+
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue('a');
+      c.enqueue('b');
+      c.close();
+    }
+  });
+
+  const reader1 = rs.getReader();
+  const promise1 = reader1.read().then(r => {
+    assert_object_equals(r, { value: 'a', done: false }, 'reading the first chunk from reader1 works');
+  });
+  reader1.releaseLock();
+
+  const reader2 = rs.getReader();
+  const promise2 = reader2.read().then(r => {
+    assert_object_equals(r, { value: 'b', done: false }, 'reading the second chunk from reader2 works');
+  });
+  reader2.releaseLock();
+
+  return Promise.all([promise1, promise2]);
+
+}, 'Multiple readers can access the stream in sequence');
+
+promise_test(() => {
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue('a');
+    }
+  });
+
+  const reader1 = rs.getReader();
+  reader1.releaseLock();
+
+  const reader2 = rs.getReader();
+
+  // Should be a no-op
+  reader1.releaseLock();
+
+  return reader2.read().then(result => {
+    assert_object_equals(result, { value: 'a', done: false },
+                         'read() should still work on reader2 even after reader1 is released');
+  });
+
+}, 'Cannot use an already-released reader to unlock a stream again');
+
+promise_test(t => {
+
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue('a');
+    },
+    cancel() {
+      assert_unreached('underlying source cancel should not be called');
+    }
+  });
+
+  const reader = rs.getReader();
+  reader.releaseLock();
+  const cancelPromise = reader.cancel();
+
+  const reader2 = rs.getReader();
+  const readPromise = reader2.read().then(r => {
+    assert_object_equals(r, { value: 'a', done: false }, 'a new reader should be able to read a chunk');
+  });
+
+  return Promise.all([
+    promise_rejects(t, new TypeError(), cancelPromise),
+    readPromise
+  ]);
+
+}, 'cancel() on a released reader is a no-op and does not pass through');
+
+promise_test(t => {
+
+  const promiseAsserts = [];
+
+  let controller;
+  const theError = { name: 'unique error' };
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const reader1 = rs.getReader();
+
+  promiseAsserts.push(
+    promise_rejects(t, theError, reader1.closed),
+    promise_rejects(t, theError, reader1.read())
+  );
+
+  assert_throws(new TypeError(), () => rs.getReader(), 'trying to get another reader before erroring should throw');
+
+  controller.error(theError);
+
+  reader1.releaseLock();
+
+  const reader2 = rs.getReader();
+
+  promiseAsserts.push(
+    promise_rejects(t, theError, reader2.closed),
+    promise_rejects(t, theError, reader2.read())
+  );
+
+  return Promise.all(promiseAsserts);
+
+}, 'Getting a second reader after erroring the stream and releasing the reader should succeed');
+
+promise_test(t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const promise = rs.getReader().closed.then(
+    t.unreached_func('closed promise should not be fulfilled when stream is errored'),
+    err => {
+      assert_equals(err, undefined, 'passed error should be undefined as it was');
+    }
+  );
+
+  controller.error();
+  return promise;
+
+}, 'ReadableStreamReader closed promise should be rejected with undefined if that is the error');
+
+
+promise_test(t => {
+
+  const rs = new ReadableStream({
+    start() {
+      return Promise.reject();
+    }
+  });
+
+  return rs.getReader().read().then(
+    t.unreached_func('read promise should not be fulfilled when stream is errored'),
+    err => {
+      assert_equals(err, undefined, 'passed error should be undefined as it was');
+    }
+  );
+
+}, 'ReadableStreamReader: if start rejects with no parameter, it should error the stream with an undefined error');
+
+promise_test(t => {
+
+  const theError = { name: 'unique string' };
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const promise = promise_rejects(t, theError, rs.getReader().closed);
+
+  controller.error(theError);
+  return promise;
+
+}, 'Erroring a ReadableStream after checking closed should reject ReadableStreamReader closed promise');
+
+promise_test(t => {
+
+  const theError = { name: 'unique string' };
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  controller.error(theError);
+
+  // Let's call getReader twice for extra test coverage of this code path.
+  rs.getReader().releaseLock();
+
+  return promise_rejects(t, theError, rs.getReader().closed);
+
+}, 'Erroring a ReadableStream before checking closed should reject ReadableStreamReader closed promise');
+
+promise_test(() => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+  const reader = rs.getReader();
+
+  const promise = Promise.all([
+    reader.read().then(result => {
+      assert_object_equals(result, { value: undefined, done: true }, 'read() should fulfill with close (1)');
+    }),
+    reader.read().then(result => {
+      assert_object_equals(result, { value: undefined, done: true }, 'read() should fulfill with close (2)');
+    }),
+    reader.closed
+  ]);
+
+  controller.close();
+  return promise;
+
+}, 'Reading twice on a stream that gets closed');
+
+promise_test(() => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  controller.close();
+  const reader = rs.getReader();
+
+  return Promise.all([
+    reader.read().then(result => {
+      assert_object_equals(result, { value: undefined, done: true }, 'read() should fulfill with close (1)');
+    }),
+    reader.read().then(result => {
+      assert_object_equals(result, { value: undefined, done: true }, 'read() should fulfill with close (2)');
+    }),
+    reader.closed
+  ]);
+
+}, 'Reading twice on a closed stream');
+
+promise_test(t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const myError = { name: 'mashed potatoes' };
+  controller.error(myError);
+
+  const reader = rs.getReader();
+
+  return Promise.all([
+    promise_rejects(t, myError, reader.read()),
+    promise_rejects(t, myError, reader.read()),
+    promise_rejects(t, myError, reader.closed)
+  ]);
+
+}, 'Reading twice on an errored stream');
+
+promise_test(t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const myError = { name: 'mashed potatoes' };
+  const reader = rs.getReader();
+
+  const promise = Promise.all([
+    promise_rejects(t, myError, reader.read()),
+    promise_rejects(t, myError, reader.read()),
+    promise_rejects(t, myError, reader.closed)
+  ]);
+
+  controller.error(myError);
+  return promise;
+
+}, 'Reading twice on a stream that gets errored');
+
+done();