<!doctype html>
<meta charset=utf-8>
<title>RTCPeerConnection.prototype.createAnswer</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="RTCPeerConnection-helper.js"></script>
<script>
'use strict';

promise_test(async t => {
  const pc = new RTCPeerConnection();
  t.add_cleanup(() => pc.close());

  await promise_rejects_dom(t, 'InvalidStateError', pc.createAnswer());
}, 'createAnswer() with null remoteDescription should reject with InvalidStateError');

promise_test(async t => {
  const pc = new RTCPeerConnection();
  t.add_cleanup(() => pc.close());

  const offer = await generateVideoReceiveOnlyOffer(pc);
  await pc.setRemoteDescription(offer);
  const answer = await pc.createAnswer();
  assert_equals(typeof answer, 'object',
    'Expect answer to be plain object dictionary RTCSessionDescriptionInit');
  assert_false(answer instanceof RTCSessionDescription,
    'Expect answer to not be instance of RTCSessionDescription');
}, 'createAnswer() after setting remote description should succeed');

promise_test(async t => {
  const pc = new RTCPeerConnection();
  t.add_cleanup(() => pc.close());

  // generateDataChannelOffer() is defined in RTCPeerConnection-helper.js.
  const offer = await generateDataChannelOffer(pc);
  await pc.setRemoteDescription(offer);
  pc.close();
  await promise_rejects_dom(t, 'InvalidStateError', pc.createAnswer());
}, 'createAnswer() when connection is closed should reject with InvalidStateError');

</script>
