url.startsWith is not a function.

[Erwin-Goossen]

Describe the bug
Happy-dom throws the next error:
TypeError: url.startsWith is not a function. (In 'url.startsWith("about:")', 'url.startsWith' is undefined)

To Reproduce
Steps to reproduce the behavior:
Not sure tbh. But did some debugging and partly found the cause of this.

This is the part where it fails in BrowserFrameURL:

static getRelativeURL(frame, url) {
    url = (url instanceof URL ? url.toString() : url) || 'about:blank';
    if (url.startsWith('about:') || url.startsWith('javascript:')) {

The problem is that url is not an instance of URL, but still an object, alyhough the string value is about:blank. Because of not being an instance of URL, but still being an object the .startsWith fails.

replacing the url assignment with url = (url instanceof URL || typeof url === 'object' ? url.toString() : url) || 'about:blank'; fixes the error/issue

Expected behavior
Happy-dom not to throw an error on a 'wrong' url

Screenshots
If applicable, add screenshots to help explain your problem.

Device:

• OS: macOS 14.6.1 (23G93)
• Browser Bun vv1.1.42
• Version 16.2.7

Additional context
Add any other context about the problem here.

TypeError: url.startsWith is not a function. (In 'url.startsWith("about:")', 'url.startsWith' is undefined)
      at getRelativeURL (<path-to-project></>/node_modules/happy-dom/lib/browser/utilities/BrowserFrameURL.js:16:17)
      at <path-to-project></>/node_modules/happy-dom/lib/browser/utilities/BrowserFrameNavigator.js:63:20
      at navigate (<path-to-project></>/node_modules/happy-dom/lib/browser/utilities/BrowserFrameNavigator.js:57:44)
      at href (<path-to-project></>/node_modules/happy-dom/lib/location/Location.js:210:13)
      at location (<path-to-project></>/node_modules/happy-dom/lib/window/BrowserWindow.js:904:31)
      at <path-to-project></>/src/components/Popup/Popup.spec.tsx:40:6```

[capricorn86]

Thank you for reporting @Erwin-Goossen! 🙂

Support for this should now be added in v16.4.2