webrtc/RTCDataChannel-send.html - external/w3c/web-platform-tests - Git at Google

 <!doctype html>
 <meta charset=utf-8>
 <meta name="timeout" content="long">
 <title>RTCDataChannel.prototype.send</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="RTCPeerConnection-helper.js"></script>
 <script src="RTCDataChannel-helper.js"></script>
 <script src="third_party/sdp/sdp.js"></script>
 <script>
 'use strict';

 // Test is based on the following editor draft:
 // https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.html

 // The following helper functions are called from RTCPeerConnection-helper.js:
 // createDataChannelPair
 // awaitMessage
 // blobToArrayBuffer
 // assert_equals_typed_array

 /*
  6.2. RTCDataChannel
  interface RTCDataChannel : EventTarget {
  ...
  readonly attribute RTCDataChannelState readyState;
  readonly attribute unsigned long bufferedAmount;
  attribute EventHandler onmessage;
  attribute DOMString binaryType;

  void send(USVString data);
  void send(Blob data);
  void send(ArrayBuffer data);
  void send(ArrayBufferView data);
  };
  */

 // Simple ASCII encoded string
 const helloString = 'hello';
 const emptyString = '';
 // ASCII encoded buffer representation of the string
 const helloBuffer = Uint8Array.of(0x68, 0x65, 0x6c, 0x6c, 0x6f);
 const emptyBuffer = new Uint8Array();
 const helloBlob = new Blob([helloBuffer]);

 // Unicode string with multiple code units
 const unicodeString = '世界你好';
 // UTF-8 encoded buffer representation of the string
 const unicodeBuffer = Uint8Array.of(
  0xe4, 0xb8, 0x96, 0xe7, 0x95, 0x8c,
  0xe4, 0xbd, 0xa0, 0xe5, 0xa5, 0xbd);

 /*
  6.2. send()
  2. If channel's readyState attribute is connecting, throw an InvalidStateError.
  */
 test(t => {
  const pc = new RTCPeerConnection();
  const channel = pc.createDataChannel('test');
  assert_equals(channel.readyState, 'connecting');
  assert_throws_dom('InvalidStateError', () => channel.send(helloString));
 }, 'Calling send() when data channel is in connecting state should throw InvalidStateError');

 for (const options of [{}, {negotiated: true, id: 0}]) {
  const mode = `${options.negotiated? "Negotiated d" : "D"}atachannel`;

  /*
  6.2. send()
  3. Execute the sub step that corresponds to the type of the methods argument:

  string object
  Let data be the object and increase the bufferedAmount attribute
  by the number of bytes needed to express data as UTF-8.

  [WebSocket]
  5. Feedback from the protocol
  When a WebSocket message has been received
  4. If type indicates that the data is Text, then initialize event's data
  attribute to data.
  */
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel1.send(helloString);
  return awaitMessage(channel2)
  }).then(message => {
  assert_equals(typeof message, 'string',
  'Expect message to be a string');

  assert_equals(message, helloString);
  });
  }, `${mode} should be able to send simple string and receive as string`);

  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel1.send(unicodeString);
  return awaitMessage(channel2)
  }).then(message => {
  assert_equals(typeof message, 'string',
  'Expect message to be a string');

  assert_equals(message, unicodeString);
  });
  }, `${mode} should be able to send unicode string and receive as unicode string`);
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel2.binaryType = 'arraybuffer';
  channel1.send(helloString);
  return awaitMessage(channel2);
  }).then(message => {
  assert_equals(typeof message, 'string',
  'Expect message to be a string');

  assert_equals(message, helloString);
  });
  }, `${mode} should ignore binaryType and always receive string message as string`);
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel1.send(emptyString);
  // Send a non-empty string in case the implementation ignores empty messages
  channel1.send(helloString);
  return awaitMessage(channel2)
  }).then(message => {
  assert_equals(typeof message, 'string',
  'Expect message to be a string');

  assert_equals(message, emptyString);
  });
  }, `${mode} should be able to send an empty string and receive an empty string`);

  /*
  6.2. send()
  3. Execute the sub step that corresponds to the type of the methods argument:
  ArrayBufferView object
  Let data be the data stored in the section of the buffer described
  by the ArrayBuffer object that the ArrayBufferView object references
  and increase the bufferedAmount attribute by the length of the
  ArrayBufferView in bytes.

  [WebSocket]
  5. Feedback from the protocol
  When a WebSocket message has been received
  4. If binaryType is set to "arraybuffer", then initialize event's data
  attribute to a new read-only ArrayBuffer object whose contents are data.

  [WebIDL]
  4.1. ArrayBufferView
  typedef (Int8Array or Int16Array or Int32Array or
  Uint8Array or Uint16Array or Uint32Array or Uint8ClampedArray or
  Float32Array or Float64Array or DataView) ArrayBufferView;
  */
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel2.binaryType = 'arraybuffer';
  channel1.send(helloBuffer);
  return awaitMessage(channel2)
  }).then(messageBuffer => {
  assert_true(messageBuffer instanceof ArrayBuffer,
  'Expect messageBuffer to be an ArrayBuffer');

  assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
  });
  }, `${mode} should be able to send Uint8Array message and receive as ArrayBuffer`);

  /*
  6.2. send()
  3. Execute the sub step that corresponds to the type of the methods argument:
  ArrayBuffer object
  Let data be the data stored in the buffer described by the ArrayBuffer
  object and increase the bufferedAmount attribute by the length of the
  ArrayBuffer in bytes.
  */
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel2.binaryType = 'arraybuffer';
  channel1.send(helloBuffer.buffer);
  return awaitMessage(channel2)
  }).then(messageBuffer => {
  assert_true(messageBuffer instanceof ArrayBuffer,
  'Expect messageBuffer to be an ArrayBuffer');

  assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
  });
  }, `${mode} should be able to send ArrayBuffer message and receive as ArrayBuffer`);

  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel2.binaryType = 'arraybuffer';
  channel1.send(emptyBuffer.buffer);
  // Send a non-empty buffer in case the implementation ignores empty messages
  channel1.send(helloBuffer.buffer);
  return awaitMessage(channel2)
  }).then(messageBuffer => {
  assert_true(messageBuffer instanceof ArrayBuffer,
  'Expect messageBuffer to be an ArrayBuffer');

  assert_equals_typed_array(messageBuffer, emptyBuffer.buffer);
  });
  }, `${mode} should be able to send an empty ArrayBuffer message and receive as ArrayBuffer`);

  /*
  6.2. send()
  3. Execute the sub step that corresponds to the type of the methods argument:
  Blob object
  Let data be the raw data represented by the Blob object and increase
  the bufferedAmount attribute by the size of data, in bytes.
  */
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel2.binaryType = 'arraybuffer';
  channel1.send(helloBlob);
  return awaitMessage(channel2);
  }).then(messageBuffer => {
  assert_true(messageBuffer instanceof ArrayBuffer,
  'Expect messageBuffer to be an ArrayBuffer');

  assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
  });
  }, `${mode} should be able to send Blob message and receive as ArrayBuffer`);

  /*
  [WebSocket]
  5. Feedback from the protocol
  When a WebSocket message has been received
  4. If binaryType is set to "blob", then initialize event's data attribute
  to a new Blob object that represents data as its raw data.
  */
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel2.binaryType = 'blob';
  channel1.send(helloBuffer);
  return awaitMessage(channel2);
  })
  .then(messageBlob => {
  assert_true(messageBlob instanceof Blob,
  'Expect received messageBlob to be a Blob');

  return blobToArrayBuffer(messageBlob);
  }).then(messageBuffer => {
  assert_true(messageBuffer instanceof ArrayBuffer,
  'Expect messageBuffer to be an ArrayBuffer');

  assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
  });
  }, `${mode} should be able to send ArrayBuffer message and receive as Blob`);

  /*
  6.2. RTCDataChannel
  binaryType
  The binaryType attribute must, on getting, return the value to which it was
  last set. On setting, the user agent must set the IDL attribute to the new
  value. When a RTCDataChannel object is created, the binaryType attribute must
  be initialized to the string "blob".
  */
  promise_test(t => {
  return createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  assert_equals(channel2.binaryType, 'arraybuffer',
  'Expect initial binaryType value to be arraybuffer');

  channel1.send(helloBuffer);
  return awaitMessage(channel2);
  }).then(messageBuffer => {
  assert_true(messageBuffer instanceof ArrayBuffer,
  'Expect messageBuffer to be an ArrayBuffer');

  assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
  });
  }, `${mode} binaryType should receive message as ArrayBuffer by default`);

  // Test sending 3 messages: helloBuffer, unicodeString, helloBlob
  async_test(t => {
  const receivedMessages = [];

  const onMessage = t.step_func(event => {
  const { data } = event;
  receivedMessages.push(data);

  if(receivedMessages.length === 3) {
  assert_equals_typed_array(receivedMessages[0], helloBuffer.buffer);
  assert_equals(receivedMessages[1], unicodeString);
  assert_equals_typed_array(receivedMessages[2], helloBuffer.buffer);

  t.done();
  }
  });

  createDataChannelPair(t, options)
  .then(([channel1, channel2]) => {
  channel2.binaryType = 'arraybuffer';
  channel2.addEventListener('message', onMessage);

  channel1.send(helloBuffer);
  channel1.send(unicodeString);
  channel1.send(helloBlob);

  }).catch(t.step_func(err =>
  assert_unreached(`Unexpected promise rejection: ${err}`)));
  }, `${mode} sending multiple messages with different types should succeed and be received`);

  /*
  [Deferred]
  6.2. RTCDataChannel
  The send() method is being amended in w3c/webrtc-pc#1209 to throw error instead
  of closing data channel when buffer is full

  send()
  4. If channel's underlying data transport is not established yet, or if the
  closing procedure has started, then abort these steps.
  5. Attempt to send data on channel's underlying data transport; if the data
  cannot be sent, e.g. because it would need to be buffered but the buffer
  is full, the user agent must abruptly close channel's underlying data
  transport with an error.

  test(t => {
  const pc = new RTCPeerConnection();
  const channel = pc.createDataChannel('test');
  channel.close();
  assert_equals(channel.readyState, 'closing');
  channel.send(helloString);
  }, 'Calling send() when data channel is in closing state should succeed');
  */
 }

  promise_test(async t => {
  // This test uses some bundle shenanigans to cause packet loss
  // The intent is to create a situation where a small message is received
  // when there is a partially received large message, and check whether
  // that small message is misinterpreted as part of the large message
  // instead of its own thing.
  const pc1 = new RTCPeerConnection({bundlePolicy: 'balanced'});
  const pc2 = new RTCPeerConnection();
  pc1.addTransceiver('audio');
  pc1.addTransceiver('video');
  const channel1 = pc1.createDataChannel('foo', {id: 1, ordered: false, negotiated: true});
  const channel2 = pc2.createDataChannel('foo', {id: 1, ordered: false, negotiated: true});
  const channel1Open = new Promise(r => channel1.onopen = r);
  const channel2Open = new Promise(r => channel2.onopen = r);
  exchangeIceCandidates(pc1, pc2);

  const size = 1024*1024*5;
  const bigMessage = 'a'.repeat(size);
  const smallMessage = 'boom';
  const numLittle = 1000;

  const receivedMessages = new Promise((resolve, reject) => {
  let littleReceived = 0;
  let bigReceived = false;
  channel2.onmessage = ({data}) => {
  try {
  if (data.length == size) {
  assert_false(bigReceived, 'Only received big message once');
  bigReceived = true;
  assert_equals(data, bigMessage, 'Big message has correct contents');
  } else if (data.length == smallMessage.length) {
  littleReceived++;
  assert_equals(data, smallMessage, 'Small message has correct contents');
  assert_less_than_equal(littleReceived, numLittle, 'Got no more than expected small messages');
  } else {
  assert_true(false, `Message was an expected size (got ${data.length}, last bytes are ${data.slice(-20)})`);
  }

  if (littleReceived == 1000 && bigReceived) {
  resolve();
  }
  } catch (e) {
  reject(e);
  }
  };
  });

  function rebundleMids(offer, mids) {
  // Disable any existing groups
  let sdp = offer.sdp.replaceAll('a=group:BUNDLE','a=moop:BUNGLE');
  sdp = sdp.replaceAll('a=msid-semantic:', 'a=msid-pedantic:');
  // Create group attrs for the mids we want
  const midsString = mids.join(' ');
  sdp = sdp.replace('\r\nm=', `\r\na=group:BUNDLE ${midsString}\r\na=msid-semantic:WMS *\r\nm=`);
  return {type: 'offer', sdp};
  }

  await pc1.setLocalDescription();
  let offer = pc1.localDescription;

  // offer should have three separate transports, one for each mid
  const sections = SDPUtils.splitSections(offer.sdp);
  assert_equals(sections.length, 4);
  const mids = sections.slice(1).map(section => SDPUtils.getMid(section));
  assert_equals(mids.length, 3);

  // Cause the DataChannel msection to be bundled with the audio msection
  await pc2.setRemoteDescription(rebundleMids(offer, [mids[0], mids[2]]));
  await pc2.setLocalDescription();
  await pc1.setRemoteDescription(pc2.localDescription);
  await channel1Open;
  await channel2Open;

  channel1.send(bigMessage);

  // Send until we're almost done with the first (big) message
  channel1.bufferedAmountLowThreshold = 20000;
  await new Promise(r => channel1.onbufferedamountlow = r);

  // Ok, now for the shenanigans
  let reoffer = await pc1.createOffer();
  // Make pc2 _think_ the datachannel is now bundled with the video msection,
  // so it will discard the packets
  await pc2.setRemoteDescription(rebundleMids(reoffer, [mids[1], mids[2]]));
  await pc2.setLocalDescription();

  for (let i = 0; i < numLittle; i++) {
  channel1.send('boom');
  }

  // Now, put it back the way it is supposed to be
  await pc1.setLocalDescription();
  reoffer = pc1.localDescription;
  await pc2.setRemoteDescription(rebundleMids(reoffer, [mids[0], mids[2]]));
  await pc2.setLocalDescription();
  await pc1.setRemoteDescription(pc2.localDescription);
  await receivedMessages;
  }, `Sending multiple messages simultaneously in unordered mode works reliably`);

 promise_test(async () => {
  const offerer = new RTCPeerConnection();
  const answerer = new RTCPeerConnection();
  const channel1 = offerer.createDataChannel('foo');

  const toSend = [];
  for (let i = 0; i < 100; i++) {
  toSend.push(`So anyway I started blastin' ${i}`);
  }

  function blastMessages(channel) {
  assert_equals(channel.readyState, 'open', 'channel should already be open');
  for (const message of toSend) {
  channel.send(message);
  }
  }

  // Set up both channels to send messages as soon as they are open
  channel1.onopen = () => blastMessages(channel1);

  const channel2Created = new Promise(r => {
  answerer.ondatachannel = ({channel}) => {
  blastMessages(channel);
  r(channel);
  }
  });

  async function receiveMessages(channel) {
  const received = [];
  while (received.length < toSend.length) {
  const {data} = await new Promise(r => channel.onmessage = r);
  received.push(data);
  }
  return received;
  }

  const received1 = receiveMessages(channel1);

  await negotiate(offerer, answerer);

  const channel2 = await channel2Created;
  assert_array_equals(await receiveMessages(channel2), toSend);
  assert_array_equals(await received1, toSend);
 }, 'Sending before the other side is open should work');


 </script>
	<!doctype html>
	<meta charset=utf-8>
	<meta name="timeout" content="long">
	<title>RTCDataChannel.prototype.send</title>
	<script src="/resources/testharness.js"></script>
	<script src="/resources/testharnessreport.js"></script>
	<script src="RTCPeerConnection-helper.js"></script>
	<script src="RTCDataChannel-helper.js"></script>
	<script src="third_party/sdp/sdp.js"></script>
	<script>
	'use strict';

	// Test is based on the following editor draft:
	// https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.html

	// The following helper functions are called from RTCPeerConnection-helper.js:
	// createDataChannelPair
	// awaitMessage
	// blobToArrayBuffer
	// assert_equals_typed_array

	/*
	6.2. RTCDataChannel
	interface RTCDataChannel : EventTarget {
	...
	readonly attribute RTCDataChannelState readyState;
	readonly attribute unsigned long bufferedAmount;
	attribute EventHandler onmessage;
	attribute DOMString binaryType;

	void send(USVString data);
	void send(Blob data);
	void send(ArrayBuffer data);
	void send(ArrayBufferView data);
	};
	*/

	// Simple ASCII encoded string
	const helloString = 'hello';
	const emptyString = '';
	// ASCII encoded buffer representation of the string
	const helloBuffer = Uint8Array.of(0x68, 0x65, 0x6c, 0x6c, 0x6f);
	const emptyBuffer = new Uint8Array();
	const helloBlob = new Blob([helloBuffer]);

	// Unicode string with multiple code units
	const unicodeString = '世界你好';
	// UTF-8 encoded buffer representation of the string
	const unicodeBuffer = Uint8Array.of(
	0xe4, 0xb8, 0x96, 0xe7, 0x95, 0x8c,
	0xe4, 0xbd, 0xa0, 0xe5, 0xa5, 0xbd);

	/*
	6.2. send()
	2. If channel's readyState attribute is connecting, throw an InvalidStateError.
	*/
	test(t => {
	const pc = new RTCPeerConnection();
	const channel = pc.createDataChannel('test');
	assert_equals(channel.readyState, 'connecting');
	assert_throws_dom('InvalidStateError', () => channel.send(helloString));
	}, 'Calling send() when data channel is in connecting state should throw InvalidStateError');

	for (const options of [{}, {negotiated: true, id: 0}]) {
	const mode = `${options.negotiated? "Negotiated d" : "D"}atachannel`;

	/*
	6.2. send()
	3. Execute the sub step that corresponds to the type of the methods argument:

	string object
	Let data be the object and increase the bufferedAmount attribute
	by the number of bytes needed to express data as UTF-8.

	[WebSocket]
	5. Feedback from the protocol
	When a WebSocket message has been received
	4. If type indicates that the data is Text, then initialize event's data
	attribute to data.
	*/
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel1.send(helloString);
	return awaitMessage(channel2)
	}).then(message => {
	assert_equals(typeof message, 'string',
	'Expect message to be a string');

	assert_equals(message, helloString);
	});
	}, `${mode} should be able to send simple string and receive as string`);

	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel1.send(unicodeString);
	return awaitMessage(channel2)
	}).then(message => {
	assert_equals(typeof message, 'string',
	'Expect message to be a string');

	assert_equals(message, unicodeString);
	});
	}, `${mode} should be able to send unicode string and receive as unicode string`);
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel2.binaryType = 'arraybuffer';
	channel1.send(helloString);
	return awaitMessage(channel2);
	}).then(message => {
	assert_equals(typeof message, 'string',
	'Expect message to be a string');

	assert_equals(message, helloString);
	});
	}, `${mode} should ignore binaryType and always receive string message as string`);
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel1.send(emptyString);
	// Send a non-empty string in case the implementation ignores empty messages
	channel1.send(helloString);
	return awaitMessage(channel2)
	}).then(message => {
	assert_equals(typeof message, 'string',
	'Expect message to be a string');

	assert_equals(message, emptyString);
	});
	}, `${mode} should be able to send an empty string and receive an empty string`);

	/*
	6.2. send()
	3. Execute the sub step that corresponds to the type of the methods argument:
	ArrayBufferView object
	Let data be the data stored in the section of the buffer described
	by the ArrayBuffer object that the ArrayBufferView object references
	and increase the bufferedAmount attribute by the length of the
	ArrayBufferView in bytes.

	[WebSocket]
	5. Feedback from the protocol
	When a WebSocket message has been received
	4. If binaryType is set to "arraybuffer", then initialize event's data
	attribute to a new read-only ArrayBuffer object whose contents are data.

	[WebIDL]
	4.1. ArrayBufferView
	typedef (Int8Array or Int16Array or Int32Array or
	Uint8Array or Uint16Array or Uint32Array or Uint8ClampedArray or
	Float32Array or Float64Array or DataView) ArrayBufferView;
	*/
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel2.binaryType = 'arraybuffer';
	channel1.send(helloBuffer);
	return awaitMessage(channel2)
	}).then(messageBuffer => {
	assert_true(messageBuffer instanceof ArrayBuffer,
	'Expect messageBuffer to be an ArrayBuffer');

	assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
	});
	}, `${mode} should be able to send Uint8Array message and receive as ArrayBuffer`);

	/*
	6.2. send()
	3. Execute the sub step that corresponds to the type of the methods argument:
	ArrayBuffer object
	Let data be the data stored in the buffer described by the ArrayBuffer
	object and increase the bufferedAmount attribute by the length of the
	ArrayBuffer in bytes.
	*/
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel2.binaryType = 'arraybuffer';
	channel1.send(helloBuffer.buffer);
	return awaitMessage(channel2)
	}).then(messageBuffer => {
	assert_true(messageBuffer instanceof ArrayBuffer,
	'Expect messageBuffer to be an ArrayBuffer');

	assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
	});
	}, `${mode} should be able to send ArrayBuffer message and receive as ArrayBuffer`);

	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel2.binaryType = 'arraybuffer';
	channel1.send(emptyBuffer.buffer);
	// Send a non-empty buffer in case the implementation ignores empty messages
	channel1.send(helloBuffer.buffer);
	return awaitMessage(channel2)
	}).then(messageBuffer => {
	assert_true(messageBuffer instanceof ArrayBuffer,
	'Expect messageBuffer to be an ArrayBuffer');

	assert_equals_typed_array(messageBuffer, emptyBuffer.buffer);
	});
	}, `${mode} should be able to send an empty ArrayBuffer message and receive as ArrayBuffer`);

	/*
	6.2. send()
	3. Execute the sub step that corresponds to the type of the methods argument:
	Blob object
	Let data be the raw data represented by the Blob object and increase
	the bufferedAmount attribute by the size of data, in bytes.
	*/
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel2.binaryType = 'arraybuffer';
	channel1.send(helloBlob);
	return awaitMessage(channel2);
	}).then(messageBuffer => {
	assert_true(messageBuffer instanceof ArrayBuffer,
	'Expect messageBuffer to be an ArrayBuffer');

	assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
	});
	}, `${mode} should be able to send Blob message and receive as ArrayBuffer`);

	/*
	[WebSocket]
	5. Feedback from the protocol
	When a WebSocket message has been received
	4. If binaryType is set to "blob", then initialize event's data attribute
	to a new Blob object that represents data as its raw data.
	*/
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel2.binaryType = 'blob';
	channel1.send(helloBuffer);
	return awaitMessage(channel2);
	})
	.then(messageBlob => {
	assert_true(messageBlob instanceof Blob,
	'Expect received messageBlob to be a Blob');

	return blobToArrayBuffer(messageBlob);
	}).then(messageBuffer => {
	assert_true(messageBuffer instanceof ArrayBuffer,
	'Expect messageBuffer to be an ArrayBuffer');

	assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
	});
	}, `${mode} should be able to send ArrayBuffer message and receive as Blob`);

	/*
	6.2. RTCDataChannel
	binaryType
	The binaryType attribute must, on getting, return the value to which it was
	last set. On setting, the user agent must set the IDL attribute to the new
	value. When a RTCDataChannel object is created, the binaryType attribute must
	be initialized to the string "blob".
	*/
	promise_test(t => {
	return createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	assert_equals(channel2.binaryType, 'arraybuffer',
	'Expect initial binaryType value to be arraybuffer');

	channel1.send(helloBuffer);
	return awaitMessage(channel2);
	}).then(messageBuffer => {
	assert_true(messageBuffer instanceof ArrayBuffer,
	'Expect messageBuffer to be an ArrayBuffer');

	assert_equals_typed_array(messageBuffer, helloBuffer.buffer);
	});
	}, `${mode} binaryType should receive message as ArrayBuffer by default`);

	// Test sending 3 messages: helloBuffer, unicodeString, helloBlob
	async_test(t => {
	const receivedMessages = [];

	const onMessage = t.step_func(event => {
	const { data } = event;
	receivedMessages.push(data);

	if(receivedMessages.length === 3) {
	assert_equals_typed_array(receivedMessages[0], helloBuffer.buffer);
	assert_equals(receivedMessages[1], unicodeString);
	assert_equals_typed_array(receivedMessages[2], helloBuffer.buffer);

	t.done();
	}
	});

	createDataChannelPair(t, options)
	.then(([channel1, channel2]) => {
	channel2.binaryType = 'arraybuffer';
	channel2.addEventListener('message', onMessage);

	channel1.send(helloBuffer);
	channel1.send(unicodeString);
	channel1.send(helloBlob);

	}).catch(t.step_func(err =>
	assert_unreached(`Unexpected promise rejection: ${err}`)));
	}, `${mode} sending multiple messages with different types should succeed and be received`);

	/*
	[Deferred]
	6.2. RTCDataChannel
	The send() method is being amended in w3c/webrtc-pc#1209 to throw error instead
	of closing data channel when buffer is full

	send()
	4. If channel's underlying data transport is not established yet, or if the
	closing procedure has started, then abort these steps.
	5. Attempt to send data on channel's underlying data transport; if the data
	cannot be sent, e.g. because it would need to be buffered but the buffer
	is full, the user agent must abruptly close channel's underlying data
	transport with an error.

	test(t => {
	const pc = new RTCPeerConnection();
	const channel = pc.createDataChannel('test');
	channel.close();
	assert_equals(channel.readyState, 'closing');
	channel.send(helloString);
	}, 'Calling send() when data channel is in closing state should succeed');
	*/
	}

	promise_test(async t => {
	// This test uses some bundle shenanigans to cause packet loss
	// The intent is to create a situation where a small message is received
	// when there is a partially received large message, and check whether
	// that small message is misinterpreted as part of the large message
	// instead of its own thing.
	const pc1 = new RTCPeerConnection({bundlePolicy: 'balanced'});
	const pc2 = new RTCPeerConnection();
	pc1.addTransceiver('audio');
	pc1.addTransceiver('video');
	const channel1 = pc1.createDataChannel('foo', {id: 1, ordered: false, negotiated: true});
	const channel2 = pc2.createDataChannel('foo', {id: 1, ordered: false, negotiated: true});
	const channel1Open = new Promise(r => channel1.onopen = r);
	const channel2Open = new Promise(r => channel2.onopen = r);
	exchangeIceCandidates(pc1, pc2);

	const size = 102410245;
	const bigMessage = 'a'.repeat(size);
	const smallMessage = 'boom';
	const numLittle = 1000;

	const receivedMessages = new Promise((resolve, reject) => {
	let littleReceived = 0;
	let bigReceived = false;
	channel2.onmessage = ({data}) => {
	try {
	if (data.length == size) {
	assert_false(bigReceived, 'Only received big message once');
	bigReceived = true;
	assert_equals(data, bigMessage, 'Big message has correct contents');
	} else if (data.length == smallMessage.length) {
	littleReceived++;
	assert_equals(data, smallMessage, 'Small message has correct contents');
	assert_less_than_equal(littleReceived, numLittle, 'Got no more than expected small messages');
	} else {
	assert_true(false, `Message was an expected size (got ${data.length}, last bytes are ${data.slice(-20)})`);
	}

	if (littleReceived == 1000 && bigReceived) {
	resolve();
	}
	} catch (e) {
	reject(e);
	}
	};
	});

	function rebundleMids(offer, mids) {
	// Disable any existing groups
	let sdp = offer.sdp.replaceAll('a=group:BUNDLE','a=moop:BUNGLE');
	sdp = sdp.replaceAll('a=msid-semantic:', 'a=msid-pedantic:');
	// Create group attrs for the mids we want
	const midsString = mids.join(' ');
	sdp = sdp.replace('\r\nm=', `\r\na=group:BUNDLE ${midsString}\r\na=msid-semantic:WMS *\r\nm=`);
	return {type: 'offer', sdp};
	}

	await pc1.setLocalDescription();
	let offer = pc1.localDescription;

	// offer should have three separate transports, one for each mid
	const sections = SDPUtils.splitSections(offer.sdp);
	assert_equals(sections.length, 4);
	const mids = sections.slice(1).map(section => SDPUtils.getMid(section));
	assert_equals(mids.length, 3);

	// Cause the DataChannel msection to be bundled with the audio msection
	await pc2.setRemoteDescription(rebundleMids(offer, [mids[0], mids[2]]));
	await pc2.setLocalDescription();
	await pc1.setRemoteDescription(pc2.localDescription);
	await channel1Open;
	await channel2Open;

	channel1.send(bigMessage);

	// Send until we're almost done with the first (big) message
	channel1.bufferedAmountLowThreshold = 20000;
	await new Promise(r => channel1.onbufferedamountlow = r);

	// Ok, now for the shenanigans
	let reoffer = await pc1.createOffer();
	// Make pc2 _think_ the datachannel is now bundled with the video msection,
	// so it will discard the packets
	await pc2.setRemoteDescription(rebundleMids(reoffer, [mids[1], mids[2]]));
	await pc2.setLocalDescription();

	for (let i = 0; i < numLittle; i++) {
	channel1.send('boom');
	}

	// Now, put it back the way it is supposed to be
	await pc1.setLocalDescription();
	reoffer = pc1.localDescription;
	await pc2.setRemoteDescription(rebundleMids(reoffer, [mids[0], mids[2]]));
	await pc2.setLocalDescription();
	await pc1.setRemoteDescription(pc2.localDescription);
	await receivedMessages;
	}, `Sending multiple messages simultaneously in unordered mode works reliably`);

	promise_test(async () => {
	const offerer = new RTCPeerConnection();
	const answerer = new RTCPeerConnection();
	const channel1 = offerer.createDataChannel('foo');

	const toSend = [];
	for (let i = 0; i < 100; i++) {
	toSend.push(`So anyway I started blastin' ${i}`);
	}

	function blastMessages(channel) {
	assert_equals(channel.readyState, 'open', 'channel should already be open');
	for (const message of toSend) {
	channel.send(message);
	}
	}

	// Set up both channels to send messages as soon as they are open
	channel1.onopen = () => blastMessages(channel1);

	const channel2Created = new Promise(r => {
	answerer.ondatachannel = ({channel}) => {
	blastMessages(channel);
	r(channel);
	}
	});

	async function receiveMessages(channel) {
	const received = [];
	while (received.length < toSend.length) {
	const {data} = await new Promise(r => channel.onmessage = r);
	received.push(data);
	}
	return received;
	}

	const received1 = receiveMessages(channel1);

	await negotiate(offerer, answerer);

	const channel2 = await channel2Created;
	assert_array_equals(await receiveMessages(channel2), toSend);
	assert_array_equals(await received1, toSend);
	}, 'Sending before the other side is open should work');


	</script>