Implementation of WritableStream

third_party/WebKit/LayoutTests/http/tests/streams/writable-streams/start.js

Index: third_party/WebKit/LayoutTests/http/tests/streams/writable-streams/start.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/streams/writable-streams/start.js b/third_party/WebKit/LayoutTests/http/tests/streams/writable-streams/start.js
new file mode 100644
index 0000000000000000000000000000000000000000..a328e7e0a5d602010e180d2dc8928f9131f633df
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/http/tests/streams/writable-streams/start.js
@@ -0,0 +1,107 @@
+'use strict';
+
+if (self.importScripts) {
+  self.importScripts('/resources/testharness.js');
+  self.importScripts('../resources/test-utils.js');
+  self.importScripts('../resources/recording-streams.js');
+}
+
+promise_test(() => {
+  let resolveStartPromise;
+  const ws = recordingWritableStream({
+    start() {
+      return new Promise(resolve => {
+        resolveStartPromise = resolve;
+      });
+    }
+  });
+
+  const writer = ws.getWriter();
+
+  assert_equals(writer.desiredSize, 1, 'desiredSize should be 1');
+  writer.write('a');
+  assert_equals(writer.desiredSize, 0, 'desiredSize should be 0 after writer.write()');
+
+  // Wait and verify that write isn't called.
+  return delay(100)
+      .then(() => {
+        assert_array_equals(ws.events, [], 'write should not be called until start promise resolves');
+        resolveStartPromise();
+        return writer.ready;
+      })
+      .then(() => assert_array_equals(ws.events, ['write', 'a'],
+                                      'write should not be called until start promise resolves'));
+}, 'underlying sink\'s write should not be called until start finishes');
+
+promise_test(() => {
+  let resolveStartPromise;
+  const ws = recordingWritableStream({
+    start() {
+      return new Promise(resolve => {
+        resolveStartPromise = resolve;
+      });
+    }
+  });
+
+  const writer = ws.getWriter();
+
+  writer.close();
+  assert_equals(writer.desiredSize, 1, 'desiredSize should be 1');
+
+  // Wait and verify that write isn't called.
+  return delay(100).then(() => {
+    assert_array_equals(ws.events, [], 'close should not be called until start promise resolves');
+    resolveStartPromise();
+    return writer.closed;
+  });
+}, 'underlying sink\'s close should not be called until start finishes');
+
+test(() => {
+  const passedError = new Error('horrible things');
+
+  let writeCalled = false;
+  let closeCalled = false;
+  assert_throws(passedError, () => {
+    // recordingWritableStream cannot be used here because the exception in the
+    // constructor prevents assigning the object to a variable.
+    new WritableStream({
+      start() {
+        throw passedError;
+      },
+      write() {
+        writeCalled = true;
+      },
+      close() {
+        closeCalled = true;
+      }
+    });
+  }, 'constructor should throw passedError');
+  assert_false(writeCalled, 'write should not be called');
+  assert_false(closeCalled, 'close should not be called');
+}, 'underlying sink\'s write or close should not be called if start throws');
+
+promise_test(() => {
+  const ws = recordingWritableStream({
+    start() {
+      return Promise.reject();
+    }
+  });
+
+  // Wait and verify that write or close aren't called.
+  return delay(100)
+      .then(() => assert_array_equals(ws.events, [], 'write and close should not be called'));
+}, 'underlying sink\'s write or close should not be invoked if the promise returned by start is rejected');
+
+promise_test(t => {
+  const rejection = { name: 'this is checked' };
+  const ws = new WritableStream({
+    start() {
+      return {
+        then(onFulfilled, onRejected) { onRejected(rejection); }
+      };
+    }
+  });
+  return promise_rejects(t, rejection, ws.getWriter().closed, 'closed promise should be rejected');
+}, 'returning a thenable from start() should work');
+
+done();