Re-import workers WPT

https://bugs.webkit.org/show_bug.cgi?id=260868
rdar://114647890

Reviewed by Cameron McCormack.

Upstream commit: web-platform-tests/wpt@d9e648d

Some changes landed from Mozilla that improve our Interop 2023 workers score.

* LayoutTests/http/wpt/workers/modules/dedicated-worker-import-csp-expected.txt:
* LayoutTests/http/wpt/workers/modules/dedicated-worker-import-csp.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/WorkerNavigator_userAgentData.https.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/Worker_cross_origin_security_err-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/Worker_cross_origin_security_err.htm:
* LayoutTests/imported/w3c/web-platform-tests/workers/Worker_dispatchEvent_ErrorEvent-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/Worker_dispatchEvent_ErrorEvent.htm:
* LayoutTests/imported/w3c/web-platform-tests/workers/Worker_script_mimetype-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/Worker_script_mimetype.htm:
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/SharedWorker-constructor-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/SharedWorker-constructor.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/same-origin-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/same-origin.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/w3c-import.log:
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/AbstractWorker.onerror-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/AbstractWorker.onerror.js:
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/same-origin-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/same-origin.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/dedicated-worker-in-data-url-context.window.js:
(promise_test.async t):
* LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime.any.js:
* LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime_local.any.js: Copied from LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime.any.js.
* LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime_local.any.sharedworker-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime_local.any.sharedworker.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime_local.any.worker-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime_local.any.worker.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/interfaces/WorkerUtils/navigator/007.js:
* LayoutTests/imported/w3c/web-platform-tests/workers/interfaces/WorkerUtils/navigator/008.worker-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/interfaces/WorkerUtils/navigator/008.worker.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/interfaces/WorkerUtils/navigator/008.worker.js: Added.
(test):
* LayoutTests/imported/w3c/web-platform-tests/workers/interfaces/WorkerUtils/navigator/w3c-import.log:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/dedicated-worker-import-csp.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/dedicated-worker-import-data-url-cross-origin.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/dedicated-worker-import-data-url.any.js:
(import_data_url_test):
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/dedicated-worker-import-failure-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/dedicated-worker-import-failure.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/dedicated-worker-import-meta-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/dedicated-worker-import-meta.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/shared-worker-import-data-url-cross-origin.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/shared-worker-import-data-url.window.js:
(import_data_url_test):
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/shared-worker-import-failure-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/shared-worker-import-failure.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/modules/shared-worker-parse-error-failure.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/001.worker-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/001.worker.js:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/002.worker-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/002.worker.js:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/003.any.js:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/003.any.sharedworker-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/004.any.js:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/interface-objects/004.any.sharedworker-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/multiple-workers/004.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/structured-clone/dedicated.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/semantics/structured-clone/shared.html:
* LayoutTests/imported/w3c/web-platform-tests/workers/shared-worker-in-data-url-context.window.js:
(promise_test.async t):
* LayoutTests/imported/w3c/web-platform-tests/workers/support/WorkerNavigator.js:
(async const):
* LayoutTests/imported/w3c/web-platform-tests/workers/support/w3c-import.log:
* LayoutTests/imported/w3c/web-platform-tests/workers/support/worker-request-animation-frame.js: Added.
(self.onmessage):
* LayoutTests/imported/w3c/web-platform-tests/workers/w3c-import.log:
* LayoutTests/imported/w3c/web-platform-tests/workers/worker-request-animation-frame-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/workers/worker-request-animation-frame.html: Added.
* LayoutTests/platform/mac-wk1/imported/w3c/web-platform-tests/workers/Worker_script_mimetype-expected.txt: Copied from LayoutTests/imported/w3c/web-platform-tests/workers/Worker_script_mimetype-expected.txt.
* LayoutTests/platform/mac-wk1/imported/w3c/web-platform-tests/workers/importscripts_mime_local.any.sharedworker-expected.txt: Renamed from LayoutTests/platform/mac-wk1/imported/w3c/web-platform-tests/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror-expected.txt.
* LayoutTests/tests-options.json:

Canonical link: https://commits.webkit.org/267435@main

LayoutTests/http/wpt/workers/modules/dedicated-worker-import-csp-expected.txt

@@ -5,7 +5,9 @@ FAIL script-src 'self' directive should disallow cross origin static import. ass
 PASS script-src * directive should allow cross origin static import.
 PASS worker-src * directive should override script-src 'self' directive and allow cross origin static import.
 FAIL worker-src 'self' directive should override script-src * directive and disallow cross origin static import. assert_array_equals: expected property 0 to be "ERROR" but got "export-on-load-script.js" (expected array ["ERROR"] got ["export-on-load-script.js"])
+PASS script-src-elem 'self' directive should not take effect on static import.
 PASS script-src 'self' directive should disallow cross origin dynamic import.
+PASS script-src-elem 'self' directive should disallow cross origin dynamic import.
 PASS script-src * directive should allow cross origin dynamic import.
 PASS worker-src 'self' directive should not take effect on dynamic import.
 

LayoutTests/http/wpt/workers/modules/dedicated-worker-import-csp.html

@@ -21,7 +21,7 @@
           ? '?pipe=header(Content-Security-Policy, ' + cspHeader + ')'
           : ''}`;
   // Append CSP header to scriptURL for dynamic import tests since dynamic
-  // import scripts should obey Worker script's responce's CSP.
+  // import scripts should obey Worker script's response's CSP.
   const scriptURL = `${importType}-import-remote-origin-script-worker.sub.js` +
       `${importType === 'dynamic'
           ? '?pipe=header(Content-Security-Policy, ' + cspHeader + ')'
@@ -86,6 +86,17 @@
     "worker-src 'self' directive should override script-src * directive and " +
         "disallow cross origin static import.");
 
+// For static imports on workers, the effective directive should be 'worker-src'.
+// https://w3c.github.io/webappsec-csp/#effective-directive-for-a-request
+//
+// The directive fallback list of 'worker-src' doesn't contain 'script-src-elem'
+// https://w3c.github.io/webappsec-csp/#directive-fallback-list
+import_csp_test(
+    "script-src-elem 'self' 'unsafe-inline'",
+    "static",
+    ["export-on-load-script.js"],
+    "script-src-elem 'self' directive should not take effect on static import.");
+
 // Tests for dynamic import.
 //
 // Dynamic import should obey the script-src directive instead of the worker-src
@@ -105,6 +116,14 @@
     ['ERROR'],
     "script-src 'self' directive should disallow cross origin dynamic import.");
 
+// For dynamic imports, the effective directive should be 'script-src-elem'.
+// https://w3c.github.io/webappsec-csp/#effective-directive-for-a-request
+import_csp_test(
+    "script-src-elem 'self' 'unsafe-inline'",
+    "dynamic",
+    ['ERROR'],
+    "script-src-elem 'self' directive should disallow cross origin dynamic import.");
+
 import_csp_test(
     "script-src * 'unsafe-inline'",
     "dynamic",
@@ -116,5 +135,4 @@
     "dynamic",
     ["export-on-load-script.js"],
     "worker-src 'self' directive should not take effect on dynamic import.");
-
 </script>

LayoutTests/imported/w3c/web-platform-tests/workers/WorkerNavigator_userAgentData.https.html

@@ -18,12 +18,31 @@
       assert_equals(workerUA.version, windowUA.version);
     }
     assert_equals(e.data.mobile, navigator.userAgentData.mobile);
-    const highEntropyValues = await navigator.userAgentData.getHighEntropyValues(["platform", "platformVersion", "architecture", "model", "uaFullVersion"]);
+    assert_equals(e.data.platform, navigator.userAgentData.platform);
+    const highEntropyValues = await navigator.userAgentData.getHighEntropyValues([
+      "architecture", "bitness", "fullVersionList", "model",
+      "platformVersion", "uaFullVersion", "wow64", "formFactor",
+    ]);
+
+    assert_equals(e.data.fullVersionList.length,
+                  highEntropyValues.fullVersionList.length);
+    for (let i = 0; i < e.data.fullVersionList.length; ++i) {
+      const workerFV = e.data.fullVersionList[i];
+      const windowFV = highEntropyValues.fullVersionList[i];
+      assert_equals(workerFV.brand, windowFV.brand);
+      assert_equals(workerFV.version, windowFV.version);
+    }
+
+    assert_equals(e.data.architecture, highEntropyValues.architecture);
+    assert_equals(e.data.bitness, highEntropyValues.bitness);
     assert_equals(e.data.model, highEntropyValues.model);
-    assert_equals(e.data.platform, highEntropyValues.platform);
     assert_equals(e.data.platformVersion, highEntropyValues.platformVersion);
-    assert_equals(e.data.architecture, highEntropyValues.architecture);
     assert_equals(e.data.uaFullVersion, highEntropyValues.uaFullVersion);
+    assert_equals(e.data.wow64, highEntropyValues.wow64);
+    assert_equals(e.data.formFactor, highEntropyValues.formFactor);
     assert_equals(e.data.NavigatorUADataExposed, true);
+
+    // Architecture should be one of two permitted values.
+    assert_true(["x86", "arm"].some(arch => arch == e.data.architecture))
   }, "Test that userAgentData is available in workers in secure contexts");
 </script>

LayoutTests/imported/w3c/web-platform-tests/workers/Worker_cross_origin_security_err-expected.txt

@@ -1,4 +1,4 @@
 
-PASS Cross-origin classic workers should fail to fetch
-PASS Cross-origin module workers should fail to fetch
+FAIL Cross-origin classic workers should fail to fetch The operation is insecure.
+FAIL Cross-origin module workers should fail to fetch The operation is insecure.
 

LayoutTests/imported/w3c/web-platform-tests/workers/Worker_cross_origin_security_err.htm

@@ -6,26 +6,16 @@
 <div id=log></div>
 <script>
 async_test(function(t) {
-  try {
     var w = new Worker("ftp://example.org/support/WorkerBasic.js");
     w.onerror = t.step_func_done(function(e) {
       assert_true(e instanceof Event);
     });
-  } catch (e) {
-    assert_throws_dom("SecurityError", () => {throw e}, "DOMExceptions thrown on cross-origin Worker construction must be SecurityErrors");
-    t.done();
-  }
-}, "Cross-origin classic workers should fail to fetch");
+ }, "Cross-origin classic workers should fail to fetch");
 
 async_test(function(t) {
-  try {
     var w = new Worker("ftp://example.org/support/WorkerBasic.js", {type: "module"});
     w.onerror = t.step_func_done(function(e) {
       assert_true(e instanceof Event);
     });
-  } catch (e) {
-    assert_throws_dom("SecurityError", () => {throw e}, "DOMExceptions thrown on cross-origin module Worker construction must be SecurityErrors");
-    t.done();
-  }
 }, "Cross-origin module workers should fail to fetch");
 </script>

LayoutTests/imported/w3c/web-platform-tests/workers/Worker_dispatchEvent_ErrorEvent-expected.txt

@@ -1,4 +1,5 @@
 
 PASS  ErrorEvent and Worker.dispatchEvent()
 PASS initErrorEvent
+PASS ErrorEvent constructor called as normal function
 

LayoutTests/imported/w3c/web-platform-tests/workers/Worker_dispatchEvent_ErrorEvent.htm

@@ -28,4 +28,12 @@
   var e = new ErrorEvent("error");
   assert_false("initErrorEvent" in e, "should not be supported");
 }, "initErrorEvent");
+
+test(function() {
+  assert_throws_js(
+    TypeError,
+    () => ErrorEvent(''),
+    "Calling ErrorEvent constructor without 'new' must throw"
+  );
+}, "ErrorEvent constructor called as normal function");
 </script>

LayoutTests/imported/w3c/web-platform-tests/workers/Worker_script_mimetype-expected.txt

@@ -1,5 +1,6 @@
 
 PASS HTTP(S) URLs which respond with text/plain MIME type must not work
+PASS HTTP(S) URLs which respond with text/plain MIME type must not work on SharedWorkers
 PASS blob: URLs should load, despite no MIME type for the backing Blob
 PASS blob: URLs should load, despite the wrong MIME type for the backing Blob
 PASS data: URLs should load, despite the wrong MIME type

LayoutTests/imported/w3c/web-platform-tests/workers/Worker_script_mimetype.htm

@@ -1,16 +1,23 @@
 <!DOCTYPE html>
 <title>Worker constructor with wrong MIME type scripts</title>
 <meta charset="utf-8">
+<meta name="timeout" content="long">
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 
 <script>
 async_test(t => {
   const worker = new Worker('./support/WorkerText.txt');
-  worker.onmessage = t.unreached_func("Worker should not recieve messages");
+  worker.onmessage = t.unreached_func("Worker should not receive messages");
   worker.onerror = () => t.done();
 }, "HTTP(S) URLs which respond with text/plain MIME type must not work");
 
+async_test(t => {
+  const worker = new SharedWorker('./support/WorkerText.txt');
+  worker.onmessage = t.unreached_func("Worker should not receive messages");
+  worker.onerror = () => t.done();
+}, "HTTP(S) URLs which respond with text/plain MIME type must not work on SharedWorkers");
+
 async_test(t => {
   const url = URL.createObjectURL(new Blob(['postMessage("PASS")'])); // no MIME type parameter
   const worker = new Worker(url);

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/SharedWorker-constructor-expected.txt

@@ -0,0 +1,5 @@
+
+PASS Test toString propagation exception.
+PASS Test Sharedworker creation with no arguments
+PASS Test invalid script URL.
+

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/SharedWorker-constructor.html

@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<title>Test SharedWorker constructor functionality.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+test(() => {
+  assert_throws_js(Error,
+                   function() {
+                     new SharedWorker({toString:function(){throw new Error()}})},
+                   'toString exception should be propagated');
+}, 'Test toString propagation exception.');
+
+test(() => {
+  assert_throws_js(TypeError,
+                   function() { new SharedWorker(); },
+                   'invoking SharedWorker constructor without arguments should result ' +
+                   'in an exception.')
+}, 'Test Sharedworker creation with no arguments');
+
+
+test(() => {
+  assert_throws_dom("SyntaxError",
+                    function() { var Sharedworker = new SharedWorker('http://invalid:123$'); },
+                    'Invoking SharedWorker constructor with invalid script URL should ' +
+                    'result in an exception.');
+}, 'Test invalid script URL.');
+
+</script>

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/same-origin-expected.txt

@@ -1,11 +1,11 @@
 
 PASS unsupported_scheme
 PASS data_url
-PASS javascript_url
-PASS about_blank
-PASS opera_com
-PASS port_81
-PASS https_port_80
-PASS https_port_8000
-PASS http_port_8012
+FAIL javascript_url URL of the shared worker is cross-origin
+FAIL about_blank URL of the shared worker is cross-origin
+FAIL opera_com URL of the shared worker is cross-origin
+FAIL port_81 URL of the shared worker is cross-origin
+FAIL https_port_80 URL of the shared worker is cross-origin
+FAIL https_port_8000 URL of the shared worker is cross-origin
+FAIL http_port_8012 URL of the shared worker is cross-origin
 

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/same-origin.html

@@ -10,15 +10,10 @@
 setup({allow_uncaught_exception: true});
 
 testSharedWorkerHelper = (t, script) => {
-  try {
-    const worker = new SharedWorker(script, '');
-    worker.onerror = t.step_func_done(e => {
-      assert_true(e instanceof Event);
-    });
-  } catch (e) {
-    assert_throws_dom("SecurityError", () => {throw e}, "DOMExceptions thrown on cross-origin SharedWorker construction must be SecurityErrors");
-    t.done();
-  }
+  const worker = new SharedWorker(script, '');
+  worker.onerror = t.step_func_done(e => {
+    assert_true(e instanceof Event);
+  });
 }
 
 test(() => {

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/w3c-import.log

@@ -18,8 +18,11 @@ List of files:
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/1.headers
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/Infinity
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/Infinity-arguments.html
+/LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/Infinity.headers
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/NaN
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/NaN-arguments.html
+/LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/NaN.headers
+/LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/SharedWorker-constructor.html
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/URLMismatchError.htm
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/connect-event.html
 /LayoutTests/imported/w3c/web-platform-tests/workers/constructors/SharedWorker/connect-event.js

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/AbstractWorker.onerror-expected.txt

@@ -1,4 +1,4 @@
-CONSOLE MESSAGE: SyntaxError: Unexpected token ')'
+CONSOLE MESSAGE: Error: error from onerror.js
 
 PASS AbstractWorker.onerror
 

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/AbstractWorker.onerror.js

@@ -1,5 +1,5 @@
-for (;) // should cause onerror to be invoked, but onerror is null, so
-        // the error is "not handled". should fire an ErrorEvent on the
-        // worker.
-  break;
-postMessage(1); // shouldn't do anything since the script doesn't compile
+// Throw a runtime error, the UA must report the error for that script.
+// https://html.spec.whatwg.org/#runtime-script-errors-2
+for (;;)
+  throw new Error("error from onerror.js");
+postMessage(1); // shouldn't do anything since the script doesn't compile

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/same-origin-expected.txt

@@ -1,11 +1,11 @@
 
 PASS unsupported_scheme
 PASS data_url
-PASS about_blank
-PASS example_invalid
-PASS port_81
-PASS https_port_80
-PASS https_port_8000
-PASS http_post_8012
-PASS javascript_url
+FAIL about_blank The operation is insecure.
+FAIL example_invalid The operation is insecure.
+FAIL port_81 The operation is insecure.
+FAIL https_port_80 The operation is insecure.
+FAIL https_port_8000 The operation is insecure.
+FAIL http_post_8012 The operation is insecure.
+FAIL javascript_url The operation is insecure.
 

LayoutTests/imported/w3c/web-platform-tests/workers/constructors/Worker/same-origin.html

@@ -12,15 +12,10 @@
 setup({allow_uncaught_exception: true});
 
 function testWorkerHelper(t, script) {
-  try {
-    var worker = new Worker(script);
-    worker.onerror = t.step_func_done(function(e) {
-      assert_true(e instanceof Event);
-    });
-  } catch (e) {
-    assert_throws_dom("SecurityError", () => {throw e}, "DOMExceptions thrown on cross-origin Worker construction must be SecurityErrors");
-    t.done();
-  }
+  var worker = new Worker(script);
+  worker.onerror = t.step_func_done(function(e) {
+    assert_true(e instanceof Event);
+  });
 }
 
 test(function() {

LayoutTests/imported/w3c/web-platform-tests/workers/dedicated-worker-in-data-url-context.window.js

@@ -29,8 +29,9 @@ promise_test(async t => {
       </script>
   `;
 
+  const p = new Promise(r => window.onmessage = e => r(e.data));
   const frame = await with_iframe(`data:text/html;base64,${btoa(frameCode)}`);
-  const result = await new Promise(r => window.onmessage = e => r(e.data));
+  const result = await p;
   assert_equals(result, 'PASS');
 }, 'Create a dedicated worker in a data url frame');
 
@@ -82,8 +83,9 @@ promise_test(async t => {
       </script>
   `;
 
+  const p = new Promise(r => window.onmessage = e => r(e.data));
   const frame = await with_iframe(`data:text/html;base64,${btoa(frameCode)}`);
-  const result = await new Promise(r => window.onmessage = e => r(e.data));
+  const result = await p;
   assert_equals(result, 'PASS');
 }, 'Create a data url dedicated worker in a data url frame');
 

LayoutTests/imported/w3c/web-platform-tests/workers/importscripts_mime.any.js

@@ -40,13 +40,13 @@ let test_cases = [
   ["TEXT/HTML", false],
 ];
 
-for (var test_case of test_cases) {
+for (const [mimeType, isScriptType] of test_cases) {
   test(t => {
-    let import_url = "/workers/support/imported_script.py?mime=" + test_case[0];
-    if (test_case[1]) {
+    let import_url = "/workers/support/imported_script.py?mime=" + mimeType;
+    if (isScriptType) {
       assert_equals(undefined, importScripts(import_url));
     } else {
       assert_throws_dom("NetworkError", _ => { importScripts(import_url) })
     }
-  }, "importScripts() requires scripty MIME types: " + test_case[0] + " is " + (test_case[1] ? "allowed" : "blocked") + ".");
+  }, "importScripts() requires scripty MIME types: " + mimeType + " is " + (isScriptType ? "allowed" : "blocked") + ".");
 }