preload/preload-dynamic-csp.html

<!DOCTYPE html>
<title>Makes sure that preload requests respect CSP directives that are added after the preload</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/preload/resources/preload_helper.js"></script>
<link id="preload" rel=preload href="resources/square.png" as=image>
<body>
<script>
    setup({single_test: true});

    const preload = document.querySelector("#preload");
    preload.addEventListener("load", async () => {
        const meta = document.createElement("meta");
        meta.httpEquiv = "Content-Security-Policy";
        meta.content = "img-src 'none'";
        document.head.appendChild(meta);
        const img = document.createElement("img");
        img.src = preload.href;
        document.body.appendChild(img);
        const load = new Promise(resolve => img.addEventListener("load", () => resolve('load')));
        const error = new Promise(resolve => img.addEventListener("error", () => resolve('error')));
        const result = await Promise.any([load, error]);
        assert_equals(result, "error");
        done();
    });
</script>