Awesome

Testing chrome.webstore.install without UI

In unit tests (e.g. using Selenium and ChromeDriver), one of the recurring problems is automated testing of inline installation.

The problem is that calling chrome.webstore.install creates a confirmation dialog that cannot be instrumented or controlled by ChromeDriver. There exist platform-specific hacks to click on the button (e.g. via AutoIt), but these are not reliable.

This repository provides a helper extension and a sample to show how you can achieve full test coverage without that uncontrollable dialog.

Usage

The following minimal demo (i.e. without any test frameworks) shows how you can test chrome.webstore.install without any dialog.

1. Edit helper/background.js and put the extension ID of your extension in the extensions_to_disable array at the top of the file.

2. Start Chrome in a new profile and load the two helper extensions, plus your extension/app that needs to be installed inline. Example:

   # Assume that you are in the directory of this repo
   chromium --user-data-dir=/tmp/profile --load-extension=helper,helper-app,sample/sample_extension
   

3. From the web page, call chrome.webstore.install. Here is an example: https://robwu.nl/s/chrome.webstore.install-demo.html

Example

See sample/test_example.py for an example using Selenium and Python. Install Selenium and ChromeDriver if you haven't before, start the Selenium server then run the Python script. All tests should pass without error.

See sample/TestExample.java for an example using Selenium and Java.

How does it work

1. On start-up, the helper extension disables all extensions that were placed in the extensions_to_disable array at the top of the file.
2. Whenever chrome.webstore.install is called, the extension is enabled and reloaded via a helper-app (that uses the developerPrivate API).

The mocked chrome.webstore.install closely follows the implementation of the real API of Chrome; Input is validated according to the (undocumented) rules of the inline installation API.

The helper app uses a private extension API. This only works because the extension ID is forced to be "ohmmkhmmmpcnpikjeljgnaoabkaalbgc", which actually belongs to the Chrome Apps & Extensions Developer Tool.

Notes

• Make sure that the helper extension is loaded as fast as possible.
• When the helper extension does not finish loading before the test extension, a race condition may occur and cause the test extension to be around for a split second before it is disabled.

License

Copyright 2015 Rob Wu rob@robwu.nl (https://robwu.nl) Available under the MIT license.