Implement author-constructible ReadableStream using V8 extras

third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/tee.js

Index: third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/tee.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/tee.js b/third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/tee.js
new file mode 100644
index 0000000000000000000000000000000000000000..485f2af7ab5ce4ffb69c95f8a8be54dfa1e2ed07
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/tee.js
@@ -0,0 +1,254 @@
+'use strict';
+
+if (self.importScripts) {
+  self.importScripts('../resources/rs-utils.js');
+  self.importScripts('/resources/testharness.js');
+}
+
+test(() => {
+
+  const rs = new ReadableStream();
+  const result = rs.tee();
+
+  assert_true(Array.isArray(result), 'return value should be an array');
+  assert_equals(result.length, 2, 'array should have length 2');
+  assert_equals(result[0].constructor, ReadableStream, '0th element should be a ReadableStream');
+  assert_equals(result[1].constructor, ReadableStream, '1st element should be a ReadableStream');
+
+}, 'ReadableStream teeing: rs.tee() returns an array of two ReadableStreams');
+
+promise_test(t => {
+
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue('a');
+      c.enqueue('b');
+      c.close();
+    }
+  });
+
+  const branch = rs.tee();
+  const branch1 = branch[0];
+  const branch2 = branch[1];
+  const reader1 = branch1.getReader();
+  const reader2 = branch2.getReader();
+
+  reader2.closed.then(t.unreached_func('branch2 should not be closed'));
+
+  return Promise.all([
+    reader1.closed,
+    reader1.read().then(r => {
+      assert_object_equals(r, { value: 'a', done: false }, 'first chunk from branch1 should be correct');
+    }),
+    reader1.read().then(r => {
+      assert_object_equals(r, { value: 'b', done: false }, 'second chunk from branch1 should be correct');
+    }),
+    reader1.read().then(r => {
+      assert_object_equals(r, { value: undefined, done: true }, 'third read() from branch1 should be done');
+    }),
+    reader2.read().then(r => {
+      assert_object_equals(r, { value: 'a', done: false }, 'first chunk from branch2 should be correct');
+    })
+  ]);
+
+}, 'ReadableStream teeing: should be able to read one branch to the end without affecting the other');
+
+promise_test(() => {
+
+  const theObject = { the: 'test object' };
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue(theObject);
+    }
+  });
+
+  const branch = rs.tee();
+  const branch1 = branch[0];
+  const branch2 = branch[1];
+  const reader1 = branch1.getReader();
+  const reader2 = branch2.getReader();
+
+  return Promise.all([reader1.read(), reader2.read()]).then(values => {
+    assert_object_equals(values[0], values[1], 'the values should be equal');
+  });
+
+}, 'ReadableStream teeing: values should be equal across each branch');
+
+promise_test(t => {
+
+  const theError = { name: 'boo!' };
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue('a');
+      c.enqueue('b');
+    },
+    pull() {
+      throw theError;
+    }
+  });
+
+  const branches = rs.tee();
+  const reader1 = branches[0].getReader();
+  const reader2 = branches[1].getReader();
+
+  reader1.label = 'reader1';
+  reader2.label = 'reader2';
+
+  return Promise.all([
+    promise_rejects(t, theError, reader1.closed),
+    promise_rejects(t, theError, reader2.closed),
+    reader1.read().then(r => {
+      assert_object_equals(r, { value: 'a', done: false }, 'should be able to read the first chunk in branch1');
+    }),
+    reader1.read().then(r => {
+      assert_object_equals(r, { value: 'b', done: false }, 'should be able to read the second chunk in branch1');
+
+      return promise_rejects(t, theError, reader2.read());
+    })
+    .then(() => promise_rejects(t, theError, reader1.read()))
+  ]);
+
+}, 'ReadableStream teeing: errors in the source should propagate to both branches');
+
+promise_test(() => {
+
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue('a');
+      c.enqueue('b');
+      c.close();
+    }
+  });
+
+  const branches = rs.tee();
+  const branch1 = branches[0];
+  const branch2 = branches[1];
+  branch1.cancel();
+
+  return Promise.all([
+    readableStreamToArray(branch1).then(chunks => {
+      assert_array_equals(chunks, [], 'branch1 should have no chunks');
+    }),
+    readableStreamToArray(branch2).then(chunks => {
+      assert_array_equals(chunks, ['a', 'b'], 'branch2 should have two chunks');
+    })
+  ]);
+
+}, 'ReadableStream teeing: canceling branch1 should not impact branch2');
+
+promise_test(() => {
+
+  const rs = new ReadableStream({
+    start(c) {
+      c.enqueue('a');
+      c.enqueue('b');
+      c.close();
+    }
+  });
+
+  const branches = rs.tee();
+  const branch1 = branches[0];
+  const branch2 = branches[1];
+  branch2.cancel();
+
+  return Promise.all([
+    readableStreamToArray(branch1).then(chunks => {
+      assert_array_equals(chunks, ['a', 'b'], 'branch1 should have two chunks');
+    }),
+    readableStreamToArray(branch2).then(chunks => {
+      assert_array_equals(chunks, [], 'branch2 should have no chunks');
+    })
+  ]);
+
+}, 'ReadableStream teeing: canceling branch2 should not impact branch2');
+
+promise_test(() => {
+
+  const reason1 = new Error('We\'re wanted men.');
+  const reason2 = new Error('I have the death sentence on twelve systems.');
+
+  let resolve;
+  const promise = new Promise(r => resolve = r);
+  const rs = new ReadableStream({
+    cancel(reason) {
+      assert_array_equals(reason, [reason1, reason2],
+                          'the cancel reason should be an array containing those from the branches');
+      resolve();
+    }
+  });
+
+  const branch = rs.tee();
+  const branch1 = branch[0];
+  const branch2 = branch[1];
+  branch1.cancel(reason1);
+  branch2.cancel(reason2);
+
+  return promise;
+
+}, 'ReadableStream teeing: canceling both branches should aggregate the cancel reasons into an array');
+
+promise_test(t => {
+
+  const theError = { name: 'I\'ll be careful.' };
+  const rs = new ReadableStream({
+    cancel() {
+      throw theError;
+    }
+  });
+
+  const branch = rs.tee();
+  const branch1 = branch[0];
+  const branch2 = branch[1];
+
+  return Promise.all([
+    promise_rejects(t, theError, branch1.cancel()),
+    promise_rejects(t, theError, branch2.cancel())
+  ]);
+
+}, 'ReadableStream teeing: failing to cancel the original stream should cause cancel() to reject on branches');
+
+promise_test(() => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const branches = rs.tee();
+  const reader1 = branches[0].getReader();
+  const reader2 = branches[1].getReader();
+
+  const promise = Promise.all([reader1.closed, reader2.closed]);
+
+  controller.close();
+  return promise;
+
+}, 'ReadableStream teeing: closing the original should immediately close the branches');
+
+promise_test(t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const branches = rs.tee();
+  const reader1 = branches[0].getReader();
+  const reader2 = branches[1].getReader();
+
+  const theError = { name: 'boo!' };
+  const promise = Promise.all([
+    promise_rejects(t, theError, reader1.closed),
+    promise_rejects(t, theError, reader2.closed)
+  ]);
+
+  controller.error(theError);
+  return promise;
+
+}, 'ReadableStream teeing: erroring the original should immediately error the branches');
+
+done();