Intermittent failure in /_mozilla/mozilla/window-postmessage-sameorigin.html

[jdm]

  â–¶ Unexpected subtest result in /_mozilla/mozilla/window-postmessage-sameorigin.html:
  │ FAIL [expected PASS] explicit invalid url, cloneable string message (handler)
  │   → assert_throws_js: function "function() { postMessage(message, origin) }" threw object "SyntaxError: The string did not match the expected pattern." ("SyntaxError") expected instance of function "function SyntaxError() {
  │   →     [native code]
  │   → }" ("SyntaxError")
  │ 
  │ expect_error_js/</<@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:15:7
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1867:25
  │ test@http://web-platform.test:8000/resources/testharness.js:548:30
  │ expect_error_js/<@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:14:5
  │ next_test@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:77:26
  │ @http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:84:3
  │ Tests.prototype.notify_result/<@http://web-platform.test:8000/resources/testharness.js:2593:21
  │ forEach@http://web-platform.test:8000/resources/testharness.js:3460:26
  │ Tests.prototype.notify_result@http://web-platform.test:8000/resources/testharness.js:2590:9
  │ Tests.prototype.result@http://web-platform.test:8000/resources/testharness.js:2584:14
  │ cleanup_done@http://web-platform.test:8000/resources/testharness.js:2112:15
  │ Test.prototype.cleanup@http://web-platform.test:8000/resources/testharness.js:2051:13
  │ Test.prototype.done@http://web-platform.test:8000/resources/testharness.js:1997:14
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1878:18
  │ test@http://web-platform.test:8000/resources/testharness.js:548:30
  │ expect_error_js/<@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:14:5
  │ next_test@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:77:26
  │ @http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:84:3
  │ Tests.prototype.notify_result/<@http://web-platform.test:8000/resources/testharness.js:2593:21
  │ forEach@http://web-platform.test:8000/resources/testharness.js:3460:26
  │ Tests.prototype.notify_result@http://web-platform.test:8000/resources/testharness.js:2590:9
  │ Tests.prototype.result@http://web-platform.test:8000/resources/testharness.js:2584:14
  │ cleanup_done@http://web-platform.test:8000/resources/testharness.js:2112:15
  │ Test.prototype.cleanup@http://web-platform.test:8000/resources/testharness.js:2051:13
  │ Test.prototype.done@http://web-platform.test:8000/resources/testharness.js:1997:14
  â”” Test.prototype.step_func_done/<@http://web-platform.test:8000/resources/testharness.js:1911:23

  â–¶ Unexpected subtest result in /_mozilla/mozilla/window-postmessage-sameorigin.html:
  │ FAIL [expected PASS] explicit invalid url, cloneable string message (listener)
  │   → assert_throws_js: function "function() { postMessage(message, origin) }" threw object "SyntaxError: The string did not match the expected pattern." ("SyntaxError") expected instance of function "function SyntaxError() {
  │   →     [native code]
  │   → }" ("SyntaxError")
  │ 
  │ expect_error_js/</<@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:15:7
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1867:25
  │ test@http://web-platform.test:8000/resources/testharness.js:548:30
  │ expect_error_js/<@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:14:5
  │ next_test@http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:77:26
  │ @http://web-platform.test:8000/_mozilla/mozilla/window-postmessage-sameorigin.html:84:3
  │ Tests.prototype.notify_result/<@http://web-platform.test:8000/resources/testharness.js:2593:21
  │ forEach@http://web-platform.test:8000/resources/testharness.js:3460:26
  │ Tests.prototype.notify_result@http://web-platform.test:8000/resources/testharness.js:2590:9
  │ Tests.prototype.result@http://web-platform.test:8000/resources/testharness.js:2584:14
  │ cleanup_done@http://web-platform.test:8000/resources/testharness.js:2112:15
  │ Test.prototype.cleanup@http://web-platform.test:8000/resources/testharness.js:2051:13
  │ Test.prototype.done@http://web-platform.test:8000/resources/testharness.js:1997:14
  â”” Test.prototype.step_func_done/<@http://web-platform.test:8000/resources/testharness.js:1911:23

My suspicion is that this is related to the global that is used to retrieve the SyntaxError constructor, since the objects will be different for different globals.

[gterzian]

I think it might be the test, that should use assert_throws_js(SyntaxError) as opposed to assert_throws(new SyntaxError()).

function "function() { postMessage(message, origin) }" threw object "SyntaxError: The string did not match the expected pattern." ("SyntaxError") expected instance of function "function SyntaxError()

Although kinda weird this would be intermittent? Maybe there is an underlying issue that is indeed intermittent.

[gterzian]

http://web-platform-tests.org/writing-tests/testharness-api.html#assert-throws-js-constructor-func-description

[gterzian]

Ok sorry I was actually looking at the outdated code.

I think this is a problem with our error bindings.

You can make the test pass by changing it to expect_error_dom('SYNTAX_ERR'

So it looks like we're throwing a dom exception, instead of a JS error.

I think we would need a new helper like https://github.com/servo/mozjs/blob/9b44b1e870cae2d96ea41bf2aa8a7d5eaa4cdce7/mozjs/js/rust/src/error.rs#L66

That would use this error code: https://github.com/servo/mozjs/blob/b2f83932fe9d361face14efd03f2465b9262e687/mozjs/js/public/ErrorReport.h#L52

And use it at

servo/components/script/dom/bindings/error.rs

Line 128 in f5ff38b

Error::Syntax => DOMErrorName::SyntaxError,

in the same way as is for example currently done with Type errors at

servo/components/script/dom/bindings/error.rs

Line 143 in f5ff38b

Error::Type(message) => unsafe {

So is this a change in the spec, or were we doing it wrong all along?

[jdm]

There is no JS syntax error exception object.; I should have used assert_throws_dom instead of assert_throws_js.

[jdm]

No, that's a lie. There is one, but the spec is clear that we want a dom exception: https://html.spec.whatwg.org/multipage/web-messaging.html#window-post-message-steps