Evaluating a script before page load

Sometimes you need JavaScript to run before any of the page's own scripts execute. The evaluateOnNewDocument method injects a script that runs before the page loads, on every page Browsershot navigates to. Internally it uses Puppeteer's page.evaluateOnNewDocument().

This is handy for stubbing globals, injecting polyfills, overriding navigator.webdriver, or disabling analytics before navigation.

Browsershot::url('https://example.com')
    ->evaluateOnNewDocument('window.myFlag = true')
    ->save($pathToImage);

The argument is evaluated as a script, so pass a statement rather than a function expression. The script above sets window.myFlag before any of the page's own scripts run.