fullofcaffeine / cors-js-error-test

What

This small web app can be used to test cross-origin error-reporting behavior across browsers. Providing it's correctly configured, it should serve a JS script from a different domain. It also listens to the global error event and logs its event object to the console for inspection.

Setup

1. Run npm install:
2. Setup cross.origin to map to 127.0.0.1 in your local hosts file;
3. Start the app: npm run start;
4. Open the browser you want to test on and load http://localhost:3000;
5. Open the JS inspector and inspect the logged event error object.

You might also want to disable JS caching while testing to avoid any falsey results. Here's how to do that in Chrome:

1. Open the dev tools;
2. Click the "..." menu then "Network Conditions";
3. In the tab that opens, find "Caching" and check "Disable cache".

Scenarios to test

Suggestion: test in all major browsers (Chrome, Firefox, Safari).

Cross-origin error details allowed

The app comes setup to allow cross-origin sharing of error data for js scripts served from a different origin from the top-level's. It does that by adding a crossorigin attribute to the script tag with a value of anonymous and by serving a Access-Control-Allow-Origin: * header alongside the HTTP request that serves the script file. In th

Cross-origin error details muted / sanitized

This is the default behavior for JS errors thrown from scripts loaded from a different origin. To test this, remove the crossorigin attribute from the <script> element in index.html, and in index.js remove the line that sets the header in the static middleware setup (line #6).