Use securitypolicyviolation event listener in tearDown() to check CSP violations for integration tests

[Varun Kasyap Pentamaraju]

Several integration tests currently verify that no Content Security Policy (CSP) violations occurred by inspecting browser logs in tearDown():

in django\contrib\admin\tests.py:

    def tearDown(self):
        # Ensure that no CSP violations were logged in the browser.
        self.assertEqual(self.get_browser_logs(source="security"), [])

the current logic relying on get_browser_logs() to check no CSP violations:

    def get_browser_logs(self, source=None, level="ALL"):
        """
        Return Chrome console logs filtered by level and optionally source.
        """
        try:
            logs = self.selenium.get_log("browser")
        except AttributeError:
            logs = []
        return [
            log
            for log in logs
            if (level == "ALL" or log["level"] == level)
            and (source is None or log["source"] == source)
        ]

however, get_browser_logs() is only supported for chrome and being skipped for non-chrome browsers.

A browser-independent alternative would be to register a securitypolicyviolation event listener in the test page and collect violations in tearDown().