tor-browser

link-load-error-events.sub.js (5969B)

---

/**
* This is the guts of the load/error event tests for <link rel="stylesheet">.
*
* We have a list of tests each of which is an object containing: href value,
* expected load success boolean, test description.  Href values are set up in
* such a way that we guarantee that all stylesheet URLs are unique.  This
* avoids issues around caching of sheets based on URL.
*/

// Our URLs are random, so we don't use them in error messages by
// default, but enable doing it if someone wants to debug things.
const DEBUG_URLS = false;

var isHttps = location.protocol == "https:";

var tests = [
 // Basic tests
 {
   href: existingSheet(),
   success: true,
   description: "Basic load of stylesheet",
 },
 {
   href: nonexistentSheet(),
   success: false,
   description: "Attempted load of nonexistent stylesheet",
 },
 {
   href: `data:text/css,@import url("${existingSheet()}")`,
   success: true,
   description: "Import of stylesheet",
 },
 {
   href: `data:text/css,@import url("${nonexistentSheet()}")`,
   success: false,
   description: "Import of nonexistent stylesheet",
 },
 {
   href: `data:text/css,@import url("data:text/css,@import url('${existingSheet()}')")`,
   success: true,
   description: "Import of import of stylesheet",
 },
 {
   href: `data:text/css,@import url("data:text/css,@import url('${nonexistentSheet()}')")`,
   success: false,
   description: "Import of import of nonexistent stylesheet",
 },

 // Non-CSS-response tests.
 {
   href: makeUnique(""),
   success: false,
   description: "Load of non-CSS stylesheet",
 },
 {
   href: `data:text/css,@import url("${makeUnique("")}")`,
   success: false,
   description: "Import of non-CSS stylesheet",
 },
 {
   href: `data:text/css,@import url("data:text/css,@import url('${makeUnique("")}')")`,
   success: false,
   description: "Import of import of non-CSS stylesheet",
 },

 // http:// tests, to test what happens with mixed content blocking.
 {
   href: httpSheet(),
   success: !isHttps,
   description: "Load of http:// stylesheet",
 },
 {
   href: `data:text/css,@import url("${httpSheet()}")`,
   success: !isHttps,
   description: "Import of http:// stylesheet",
 },
 {
   href: `data:text/css,@import url("data:text/css,@import url('${httpSheet()}')")`,
   success: !isHttps,
   description: "Import of import of http:// stylesheet",
 },

 // https:// tests just as a control
 {
   href: httpsSheet(),
   success: true,
   description: "Load of https:// stylesheet",
 },
 {
   href: `data:text/css,@import url("${httpsSheet()}")`,
   success: true,
   description: "Import of https:// stylesheet",
 },
 {
   href: `data:text/css,@import url("data:text/css,@import url('${httpsSheet()}')")`,
   success: true,
   description: "Import of import of https:// stylesheet",
 },

 // Tests with multiple imports some of which are slow and some are fast.
 {
   href: `data:text/css,@import url("${slowResponse(existingSheet())}"); @import url("${nonexistentSheet()}");`,
   success: false,
   description: "Slow successful import, fast failing import",
 },
 {
   href: `data:text/css,@import url("${existingSheet()}"); @import url("${slowResponse(nonexistentSheet())}");`,
   success: false,
   description: "Fast successful import, slow failing import",
 }
];

// Note: Here we really do need to use "let" at least for the href,
// because we lazily evaluate it in the unreached cases.
for (var test of tests) {
 let {href, success, description} = test;
 var t = async_test(description);
 var link = document.createElement("link");
 link.rel = "stylesheet";
 hrefString = DEBUG_URLS ? `: ${href}` : "";
 if (success) {
   link.onload = t.step_func_done(() => {});
   link.onerror = t.step_func_done(() => assert_unreached(`error fired when load expected${hrefString}`) );
 } else {
   link.onerror = t.step_func_done(() => {});
   link.onload = t.step_func_done(() => assert_unreached(`load fired when error expected${hrefString}`) );
 }
 link.href = href;
 document.head.appendChild(link);
}

/* Utility function */
function makeUnique(url) {
 // Make sure we copy here, even if the thing coming in is a URL, so we don't
 // mutate our caller's data.
 url = new URL(url, location.href);
 // We want to generate a unique URI to avoid the various caches browsers have
 // for stylesheets.  We don't want to just use a counter, because that would
 // not be robust to the test being reloaded or othewise run multiple times
 // without a browser restart.  We don't want to use timstamps, because those
 // are not likely to be unique across calls to this function, especially given
 // the degraded timer resolution browsers have due to Spectre.
 //
 // So just fall back on Math.random() and assume it can't duplicate values.
 url.searchParams.append("r", Math.random());
 return url;
}

function existingSheet() {
 return makeUnique("resources/good.css");
}

/**
* Function the add values to the "pipe" search param.  See
* http://wptserve.readthedocs.io/en/latest/pipes.html for why one would do
* this.  Because this param uses a weird '|'-separated syntax instead of just
* using multiple params with the same name, we need some manual code to munge
* the value properly.
*/
function addPipe(url, pipeVal) {
 url = new URL(url, location.href);
 var params = url.searchParams;
 var oldVal = params.get("pipe");
 if (oldVal) {
   params.set("pipe", oldVal + "|" + pipeVal);
 } else {
   params.set("pipe", pipeVal);
 }
 return url;
}

function nonexistentSheet() {
 return addPipe(existingSheet(), "status(404)");
}

function httpSheet() {
 var url = existingSheet();
 url.protocol = "http";
 url.port = {{ports[http][0]}};
 return url;
}

function httpsSheet() {
 var url = existingSheet();
 url.protocol = "https";
 url.port = {{ports[https][0]}};
 return url;
}

function slowResponse(url) {
 return addPipe(url, "trickle(d1)");
}