feat(Page.goto): add a 'domcontentloaded' option to the Page.goto (#1145)

This patch adds a new `domcontentloaded` option to a bunch of navigation
methods:
- Page.goto
- Page.waitForNavigation
- Page.goBack
- Page.goForward
- Page.reload

Fixes #946.

docs/api.md

@@ -763,6 +763,7 @@ If there's no element matching `selector`, the method throws an error.
   - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds, pass `0` to disable timeout.
   - `waitUntil` <[string]> When to consider a navigation finished, defaults to `load`. Can be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
+    - `domcontentloaded` - consider navigation to be finished when the `DOMContentLoaded` event is fired.
     - `networkidle0` - consider navigation to be finished when there are no more then 0 network connections for at least `500` ms.
     - `networkidle2` - consider navigation to be finished when there are no more then 2 network connections for at least `500` ms.
 - returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect. If
@@ -775,6 +776,7 @@ Navigate to the previous page in history.
   - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds, pass `0` to disable timeout.
   - `waitUntil` <[string]> When to consider navigation succeeded, defaults to `load`. Can be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
+    - `domcontentloaded` - consider navigation to be finished when the `DOMContentLoaded` event is fired.
     - `networkidle0` - consider navigation to be finished when there are no more then 0 network connections for at least `500` ms.
     - `networkidle2` - consider navigation to be finished when there are no more then 2 network connections for at least `500` ms.
 - returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect. If
@@ -788,6 +790,7 @@ Navigate to the next page in history.
   - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds, pass `0` to disable timeout.
   - `waitUntil` <[string]> When to consider navigation succeeded, defaults to `load`. Can be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
+    - `domcontentloaded` - consider navigation to be finished when the `DOMContentLoaded` event is fired.
     - `networkidle0` - consider navigation to be finished when there are no more then 0 network connections for at least `500` ms.
     - `networkidle2` - consider navigation to be finished when there are no more then 2 network connections for at least `500` ms.
 - returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.
@@ -902,6 +905,7 @@ Shortcut for [page.mainFrame().executionContext().queryObjects(prototypeHandle)]
   - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds, pass `0` to disable timeout.
   - `waitUntil` <[string]> When to consider navigation succeeded, defaults to `load`. Can be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
+    - `domcontentloaded` - consider navigation to be finished when the `DOMContentLoaded` event is fired.
     - `networkidle0` - consider navigation to be finished when there are no more then 0 network connections for at least `500` ms.
     - `networkidle2` - consider navigation to be finished when there are no more then 2 network connections for at least `500` ms.
 - returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.
@@ -1105,6 +1109,7 @@ Shortcut for [page.mainFrame().waitForFunction(pageFunction[, options[, ...args]
   - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds, pass `0` to disable timeout.
   - `waitUntil` <[string]> When to consider navigation succeeded, defaults to `load`. Can be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
+    - `domcontentloaded` - consider navigation to be finished when the `DOMContentLoaded` event is fired.
     - `networkidle0` - consider navigation to be finished when there are no more then 0 network connections for at least `500` ms.
     - `networkidle2` - consider navigation to be finished when there are no more then 2 network connections for at least `500` ms.
 - returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.

lib/NavigatorWatcher.js

@@ -32,7 +32,7 @@ class NavigatorWatcher {
     this._ignoreHTTPSErrors = ignoreHTTPSErrors;
     this._timeout = typeof options['timeout'] === 'number' ? options['timeout'] : 30000;
     const waitUntil = typeof options['waitUntil'] === 'string' ? options['waitUntil'] : 'load';
-    const isAllowedWaitUntil = waitUntil === 'networkidle0' || waitUntil === 'networkidle2' || waitUntil === 'load';
+    const isAllowedWaitUntil = waitUntil === 'networkidle0' || waitUntil === 'networkidle2' || waitUntil === 'load' || waitUntil === 'domcontentloaded';
     console.assert(isAllowedWaitUntil, 'Unknown value for options.waitUntil: ' + waitUntil);
     this._pendingEvents = new Set([waitUntil]);
   }
@@ -92,8 +92,9 @@ class NavigatorWatcher {
 
 const protocolLifecycleToPuppeteer = {
   'load': 'load',
+  'DOMContentLoaded': 'domcontentloaded',
   'networkIdle': 'networkidle0',
-  'networkAlmostIdle': 'networkidle2'
+  'networkAlmostIdle': 'networkidle2',
 };
 
 module.exports = NavigatorWatcher;

test/test.js

@@ -884,6 +884,10 @@ describe('Page', function() {
       const response = await page.goto('about:blank');
       expect(response).toBe(null);
     }));
+    it('should navigate to empty page with domcontentloaded', SX(async function() {
+      const response = await page.goto(EMPTY_PAGE, {waitUntil: 'domcontentloaded'});
+      expect(response.status).toBe(200);
+    }));
     it('should navigate to empty page with networkidle0', SX(async function() {
       const response = await page.goto(EMPTY_PAGE, {waitUntil: 'networkidle0'});
       expect(response.status).toBe(200);