Debugging Test Windows in Unit Tests

When creating Unit Tests, it’s often helpful to create a new Brackets window. The createTestWindowAndRun() and closeTestWindow() functions in SpecRunnerUtils makes this easy to do.

One problem with testing in this way is that you can’t step into the code in the debugger because it’s in a separate window which is created and closed too quickly to be able to manually open the Dev Tools. Here’s a technique to allow you to use the debugger in Test Windows:

1. At some point after the test window has been created, add this temporary line of code:

    testWindow.brackets.app.showDeveloperTools();

I put it in the callback passed to SpecRunnerUtils.createTestWindowAndRun(), but it can go anywhere.

2. Restart Brackets (because sometimes Reload doesn’t reload everything…)

3. Open SpecRunner: Debug > Run Tests

4. On Mac, if you’re debugging a Live Development unit test, do the following to open Chrome in debug mode: shutdown Chrome, start Live Dev, open an empty tab in Chrome, and stop Live dev.

5. From SpecRunner: Show Developer Tools

6. Set breakpoint(s) in unit test code before you start tests. The line numbers in the Dev Tools windows sometimes stop tracking the file, and, once this happens, you can’t set any more breakpoints. (Update 2/26/2013: this seems to be fixed in CEF3)

7. Leave SpecRunner Dev Tools Window open. I wasn’t hitting my breakpoint when I closed it.

8. Run your unit test

You should hit your breakpoint(s) and be able to step into code. Note that there are 2 Dev Tools windows open: 1 for Jasmine and 1 for the Brackets test window. When you step or run from code in the Jasmine Dev Tools window to a code or a breakpoint in the Brackets test Dev Tools window, there is no indication in the Jasmine Dev Tools Window and you are not automatically switched to the other window, so you’ll need to manually changed to the other Dev Tools window.

Opening a Dev Tools window for every Brackets test window slows down tests, so you may want to disable all tests except the one you are debugging.

If this is helpful, we could build it in to the createTestWindowAndRun() function and control it by a parameter or global flag. Let us know!