chore: break page.spec.js to smaller files (#2257)

Break some large chunks into smaller files. This change will remove ~600 lines from `page.spec.js`

test/CDPSession.spec.js

@@ -0,0 +1,73 @@
+/**
+ * Copyright 2018 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const {waitForEvents} = require('./utils');
+
+module.exports.addTests = function({testRunner, expect}) {
+  const {describe, xdescribe, fdescribe} = testRunner;
+  const {it, fit, xit} = testRunner;
+  const {beforeAll, beforeEach, afterAll, afterEach} = testRunner;
+
+  describe('Target.createCDPSession', function() {
+    it('should work', async function({page, server}) {
+      const client = await page.target().createCDPSession();
+
+      await Promise.all([
+        client.send('Runtime.enable'),
+        client.send('Runtime.evaluate', { expression: 'window.foo = "bar"' })
+      ]);
+      const foo = await page.evaluate(() => window.foo);
+      expect(foo).toBe('bar');
+    });
+    it('should send events', async function({page, server}) {
+      const client = await page.target().createCDPSession();
+      await client.send('Network.enable');
+      const events = [];
+      client.on('Network.requestWillBeSent', event => events.push(event));
+      await page.goto(server.EMPTY_PAGE);
+      expect(events.length).toBe(1);
+    });
+    it('should enable and disable domains independently', async function({page, server}) {
+      const client = await page.target().createCDPSession();
+      await client.send('Runtime.enable');
+      await client.send('Debugger.enable');
+      // JS coverage enables and then disables Debugger domain.
+      await page.coverage.startJSCoverage();
+      await page.coverage.stopJSCoverage();
+      // generate a script in page and wait for the event.
+      const [event] = await Promise.all([
+        waitForEvents(client, 'Debugger.scriptParsed'),
+        page.evaluate('//# sourceURL=foo.js')
+      ]);
+      // expect events to be dispatched.
+      expect(event.url).toBe('foo.js');
+    });
+    it('should be able to detach session', async function({page, server}) {
+      const client = await page.target().createCDPSession();
+      await client.send('Runtime.enable');
+      const evalResponse = await client.send('Runtime.evaluate', {expression: '1 + 2', returnByValue: true});
+      expect(evalResponse.result.value).toBe(3);
+      await client.detach();
+      let error = null;
+      try {
+        await client.send('Runtime.evaluate', {expression: '3 + 1', returnByValue: true});
+      } catch (e) {
+        error = e;
+      }
+      expect(error.message).toContain('Session closed.');
+    });
+  });
+};