<!DOCTYPE html>
<div id=result>NOTHING</div>
<script>
// Test that ReadableStream and WritableStream still work correctly when the
// global object has been interfered with.
//
// This test cannot use testharness.js because it doesn't work when you remove
// all the global objects.

'use strict';

const testRunner = self.testRunner;
if (testRunner) {
  testRunner.dumpAsText();
  testRunner.waitUntilDone();
}

async function runTest() {
  const ReadableStream = self.ReadableStream;
  const WritableStream = self.WritableStream;
  const ByteLengthQueuingStrategy = self.ByteLengthQueuingStrategy;
  const CountQueuingStrategy = self.CountQueuingStrategy;
  const Error = self.Error;
  const Promise = self.Promise;
  const Object = self.Object;
  const Object_getOwnPropertyNames = Object.getOwnPropertyNames;

  function undefineObjectProperties(o, exceptions = new Set()) {
    for (const key of Object_getOwnPropertyNames(o)) {
      if (exceptions.has(key)) {
        continue;
      }
      try {
        o[key] = undefined;
      } catch (e) {
        assert(e.name === 'TypeError', 'expecting a TypeError');
      }
    }
  }

  function assert(pred, message) {
    if (pred) {
      return;
    }
    throw new Error(message);
  }

  async function testReadAndPipeTo() {
    let done;
    const rs = new ReadableStream({
      pull(controller) {
        if (done) {
          controller.close();
        }
        assert(controller.desiredSize > 0, 'desiredSize must be greater than 0');
        controller.enqueue('tree');
      }
    });
    const reader = rs.getReader();
    assert(rs.locked, 'ReadableStream should be locked');
    await reader.read();
    reader.releaseLock();
    await rs.pipeTo(new WritableStream({
      write() {
        done = true;
      }
    }));
  }

  async function testReadableStreamClosed() {
    const rs = new ReadableStream({
      pull(controller) {
        controller.close();
      }
    });
    const reader = rs.getReader();
    await reader.read();
    await reader.closed
  }

  async function testPipeThrough() {
    const emptyRS = new ReadableStream({
      pull(controller) {
        controller.close();
      }
    });
    let resolve;
    const p = new Promise(r => {resolve = r});
    const closeResolvesWS = new WritableStream({
      close() {
        resolve();
      }
    }, new CountQueuingStrategy({ highWaterMark: 10}));
    emptyRS.pipeThrough({
      writable: closeResolvesWS,
      readable: new ReadableStream()
    }, {
      preventClose: 0,
      preventAbort: true,
      preventCancel: 'yes'
    });
    await p;
  }

  async function testReadableStreamError() {
    const rs = new ReadableStream({
      pull(controller) {
        controller.error('my error');
      }
    });
    const reader = rs.getReader();
    try {
      await reader.read();
    } catch (e) {
      assert(e === 'my error', 'my error should be thrown');
    }
  }

  async function testTee() {
    const rs = new ReadableStream({
      start(controller) {
        controller.enqueue('beef');
      }
    }, { size: () => 1, highWaterMark: 19 });
    const [left, right] = rs.tee();
    const left_cancel = left.cancel();
    const reader = right.getReader();
    const { value, done } = await reader.read();
    assert(value === 'beef', 'value should be beef');
    assert(done === false, 'done should be false');
    await reader.cancel();
    await left_cancel;
  }

  async function testWritableStreamWriteAndReleaseLock() {
    const ws = new WritableStream({}, {highWaterMark: 7});
    assert(!ws.locked, 'ws should not be locked');
    const writer = ws.getWriter();
    assert(writer.desiredSize > 0, 'desiredSize should be positive');
    await writer.ready;
    await writer.write('something');
    writer.releaseLock();
    await ws.abort();
  }

  async function testWritableStreamClose() {
    const ws = new WritableStream({}, new ByteLengthQueuingStrategy({ highWaterMark: 1024 }));
    const writer = ws.getWriter();
    await writer.close();
    await writer.closed;
  }

  async function testWritableStreamDefaultControllerError() {
    const ws = new WritableStream({
      start(controller) {
        controller.error('something bad');
      }
    });
    try {
      await ws.getWriter().closed;
    } catch (e) {
      assert(e === 'something bad', 'e should be something bad');
    }
  }

  // Undefine various prototypes and static methods that might be used in the
  // implementation.

  // The "await" keyword uses Promise.prototype.then.
  // TODO(ricea): Remove all uses of await from this test.
  undefineObjectProperties(Promise.prototype, new Set(['then']));
  undefineObjectProperties(Promise);
  undefineObjectProperties(Object.prototype);
  undefineObjectProperties(Object);
  // Array.prototype.length is writable but assigning |undefined| to it results
  // in a RangeError being thrown.
  undefineObjectProperties(Array.prototype, new Set(['length']));
  undefineObjectProperties(Array);
  undefineObjectProperties(Function.prototype);
  undefineObjectProperties(Function);
  undefineObjectProperties(Number.prototype);
  undefineObjectProperties(Number);
  undefineObjectProperties(String.prototype);
  undefineObjectProperties(String);
  undefineObjectProperties(Boolean.prototype);
  undefineObjectProperties(Boolean);
  undefineObjectProperties(Math);

  // Make methods that can be called during implicit type conversions throw.
  Object.prototype.toString = () => {
    throw new Error('Object toString() called');
  };
  Object.prototype.valueOf = () => {
    throw new Error('Object valueOf() called');
  };
  Array.prototype.toString = () => {
    throw new Error('Array toString() called');
  };
  Array.prototype.valueOf = () => {
    throw new Error('Array valueOf() called');
  };

  // Undefine (almost) everything on the global object.
  // Assigning to 'location' causes a navigation which breaks the test.
  const doNotSet = new Set(['location']);
  undefineObjectProperties(self, doNotSet);

  await testReadAndPipeTo();
  await testReadableStreamClosed();
  await testPipeThrough();
  await testReadableStreamError();
  await testTee();
  await testWritableStreamWriteAndReleaseLock();
  await testWritableStreamClose();
  await testWritableStreamDefaultControllerError();

  document.querySelector('#result').textContent = 'PASS';
  if (testRunner) {
    testRunner.notifyDone();
  }
}

runTest();
</script>