feat(page): Allow Page.goto's timeout to be 0 to disable timeout (#887)

This patch allows passing 0 to disable timeout for the following methods:

- page.goto
- page.waitForNavigation
- page.goForward
- page.goBack

Fixes #782.

docs/api.md

@@ -573,7 +573,7 @@ If there's no element matching `selector`, the method throws an error.
 
 #### page.goBack(options)
 - `options` <[Object]> Navigation parameters which might have the following properties:
-  - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds.
+  - `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`. Could be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
     - `networkidle` - consider navigation to be finished when the network activity stays "idle" for at least `networkIdleTimeout` ms.
@@ -586,7 +586,7 @@ Navigate to the previous page in history.
 
 #### page.goForward(options)
 - `options` <[Object]> Navigation parameters which might have the following properties:
-  - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds.
+  - `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`. Could be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
     - `networkidle` - consider navigation to be finished when the network activity stays "idle" for at least `networkIdleTimeout` ms.
@@ -600,7 +600,7 @@ Navigate to the next page in history.
 #### page.goto(url, options)
 - `url` <[string]> URL to navigate page to. The url should include scheme, e.g. `https://`.
 - `options` <[Object]> Navigation parameters which might have the following properties:
-  - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds.
+  - `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`. Could be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
     - `networkidle` - consider navigation to be finished when the network activity stays "idle" for at least `networkIdleTimeout` ms.
@@ -711,7 +711,7 @@ Shortcut for [`keyboard.down`](#keyboarddownkey-options) and [`keyboard.up`](#ke
 
 #### page.reload(options)
 - `options` <[Object]> Navigation parameters which might have the following properties:
-  - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds.
+  - `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`. Could be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
     - `networkidle` - consider navigation to be finished when the network activity stays "idle" for at least `networkIdleTimeout` ms.
@@ -906,7 +906,7 @@ Shortcut for [page.mainFrame().waitForFunction(pageFunction[, options[, ...args]
 
 #### page.waitForNavigation(options)
 - `options` <[Object]> Navigation parameters which might have the following properties:
-  - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds.
+  - `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`. Could be either:
     - `load` - consider navigation to be finished when the `load` event is fired.
     - `networkidle` - consider navigation to be finished when the network activity stays "idle" for at least `networkIdleTimeout` ms.

lib/NavigatorWatcher.js

@@ -40,9 +40,12 @@ class NavigatorWatcher {
 
     this._eventListeners = [];
 
-    const watchdog = new Promise(fulfill => this._maximumTimer = setTimeout(fulfill, this._timeout))
-        .then(() => 'Navigation Timeout Exceeded: ' + this._timeout + 'ms exceeded');
-    const navigationPromises = [watchdog];
+    const navigationPromises = [];
+    if (this._timeout) {
+      const watchdog = new Promise(fulfill => this._maximumTimer = setTimeout(fulfill, this._timeout))
+          .then(() => 'Navigation Timeout Exceeded: ' + this._timeout + 'ms exceeded');
+      navigationPromises.push(watchdog);
+    }
 
     if (!this._ignoreHTTPSErrors) {
       const certificateError = new Promise(fulfill => {

test/test.js

@@ -624,6 +624,11 @@ describe('Page', function() {
       expect(error.message).toContain('Navigation Timeout Exceeded: 1ms');
       process.removeListener('unhandledRejection', unhandledRejectionHandler);
     }));
+    it('should disable timeout when its set to 0', SX(async function() {
+      let error = null;
+      await page.goto(PREFIX + '/grid.html', {timeout: 0}).catch(e => error = e);
+      expect(error).toBe(null);
+    }));
     it('should work when navigating to valid url', SX(async function() {
       const response = await page.goto(EMPTY_PAGE);
       expect(response.ok).toBe(true);