<!DOCTYPE html>
<title>Custom Elements: Element definition</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<div id="log"></div>
<iframe id="iframe"></iframe>
<script>
'use strict';
(() => {
// Element definition
// https://html.spec.whatwg.org/multipage/scripting.html#element-definition
// Use window from iframe to isolate the test.
const testWindow = iframe.contentDocument.defaultView;
const customElements = testWindow.customElements;
let testable = false;
test(() => {
assert_true('customElements' in testWindow, '"window.customElements" exists');
assert_true('define' in customElements, '"window.customElements.define" exists');
testable = true;
}, '"window.customElements.define" should exists');
if (!testable)
return;
const expectTypeError = TypeError.prototype;
// Following errors are DOMException, not JavaScript errors.
const expectSyntaxError = 'SYNTAX_ERR';
const expectNotSupportedError = 'NOT_SUPPORTED_ERR';
// 1. If IsConstructor(constructor) is false,
// then throw a TypeError and abort these steps.
test(() => {
assert_throws(expectTypeError, () => {
customElements.define();
});
}, 'If no arguments, should throw a TypeError');
test(() => {
assert_throws(expectTypeError, () => {
customElements.define('test-define-one-arg');
});
}, 'If one argument, should throw a TypeError');
[
[ 'undefined', undefined ],
[ 'null', null ],
[ 'object', {} ],
[ 'string', 'string' ],
[ 'arrow function', () => {} ], // IsConstructor returns false for arrow functions
[ 'method', ({ m() { } }).m ], // IsConstructor returns false for methods
].forEach(t => {
test(() => {
assert_throws(expectTypeError, () => {
customElements.define(`test-define-constructor-${t[0]}`, t[1]);
});
}, `If constructor is ${t[0]}, should throw a TypeError`);
});
// 2. If name is not a valid custom element name,
// then throw a SyntaxError and abort these steps.
let validCustomElementNames = [
// [a-z] (PCENChar)* '-' (PCENChar)*
// https://html.spec.whatwg.org/multipage/scripting.html#valid-custom-element-name
'a-',
'a-a',
'aa-',
'aa-a',
'a-.-_',
'a-0123456789',
'a-\u6F22\u5B57', // Two CJK Unified Ideographs
'a-\uD840\uDC0B', // Surrogate pair U+2000B
];
let invalidCustomElementNames = [
undefined,
null,
'',
'-',
'a',
'input',
'mycustomelement',
'A',
'A-',
'0-',
'a-A',
'a-Z',
'A-a',
'a-a\u00D7',
'a-a\u3000',
'a-a\uDB80\uDC00', // Surrogate pair U+F0000
// name must not be any of the hyphen-containing element names.
'annotation-xml',
'color-profile',
'font-face',
'font-face-src',
'font-face-uri',
'font-face-format',
'font-face-name',
'missing-glyph',
];
validCustomElementNames.forEach(name => {
test(() => {
customElements.define(name, class {});
}, `Element names: defining an element named ${name} should succeed`);
});
invalidCustomElementNames.forEach(name => {
test(() => {
assert_throws(expectSyntaxError, () => {
customElements.define(name, class {});
});
}, `Element names: defining an element named ${name} should throw a SyntaxError`);
});
// 3. If this CustomElementRegistry contains an entry with name name,
// then throw a NotSupportedError and abort these steps.
test(() => {
customElements.define('test-define-dup-name', class {});
assert_throws(expectNotSupportedError, () => {
customElements.define('test-define-dup-name', class {});
});
}, 'If the name is already defined, should throw a NotSupportedError');
// 5. If this CustomElementRegistry contains an entry with constructor constructor,
// then throw a NotSupportedError and abort these steps.
test(() => {
class TestDupConstructor {};
customElements.define('test-define-dup-constructor', TestDupConstructor);
assert_throws(expectNotSupportedError, () => {
customElements.define('test-define-dup-ctor2', TestDupConstructor);
});
}, 'If the constructor is already defined, should throw a NotSupportedError');
// 9.1. If extends is a valid custom element name,
// then throw a NotSupportedError.
validCustomElementNames.forEach(name => {
test(() => {
assert_throws(expectNotSupportedError, () => {
customElements.define('test-define-extend-valid-name', class {}, { extends: name });
});
}, `If extends is ${name}, should throw a NotSupportedError`);
});
// 9.2. If the element interface for extends and the HTML namespace is HTMLUnknownElement
// (e.g., if extends does not indicate an element definition in this specification),
// then throw a NotSupportedError.
[
// https://html.spec.whatwg.org/multipage/dom.html#elements-in-the-dom:htmlunknownelement
'bgsound',
'blink',
'isindex',
'multicol',
'nextid',
'spacer',
'elementnametobeunknownelement',
].forEach(name => {
test(() => {
assert_throws(expectNotSupportedError, () => {
customElements.define('test-define-extend-' + name, class {}, { extends: name });
});
}, `If extends is ${name}, should throw a NotSupportedError`);
});
// 12.1. Let prototype be Get(constructor, "prototype"). Rethrow any exceptions.
function assert_rethrown(func, description) {
assert_throws({ name: 'rethrown' }, func, description);
}
function throw_rethrown_error() {
const e = new Error('check this is rethrown');
e.name = 'rethrown';
throw e;
}
test(() => {
// Hack for prototype to throw while IsConstructor is true.
const BadConstructor = (function () { }).bind({});
Object.defineProperty(BadConstructor, 'prototype', {
get() { throw_rethrown_error(); }
});
assert_rethrown(() => {
customElements.define('test-define-constructor-prototype-rethrow', BadConstructor);
});
}, 'If constructor.prototype throws, should rethrow');
// 12.2. If Type(prototype) is not Object,
// then throw a TypeError exception.
test(() => {
const c = (function () { }).bind({}); // prototype is undefined.
assert_throws(expectTypeError, () => {
customElements.define('test-define-constructor-prototype-undefined', c);
});
}, 'If Type(constructor.prototype) is undefined, should throw a TypeError');
test(() => {
function c() {};
c.prototype = 'string';
assert_throws(expectTypeError, () => {
customElements.define('test-define-constructor-prototype-string', c);
});
}, 'If Type(constructor.prototype) is string, should throw a TypeError');
// 12.3. Let lifecycleCallbacks be a map with the four keys "connectedCallback",
// "disconnectedCallback", "adoptedCallback", and "attributeChangedCallback",
// each of which belongs to an entry whose value is null.
// 12.4. For each of the four keys callbackName in lifecycleCallbacks:
// 12.4.1. Let callbackValue be Get(prototype, callbackName). Rethrow any exceptions.
// 12.4.2. If callbackValue is not undefined, then set the value of the entry in
// lifecycleCallbacks with key callbackName to the result of converting callbackValue
// to the Web IDL Function callback type. Rethrow any exceptions from the conversion.
[
'connectedCallback',
'disconnectedCallback',
'adoptedCallback',
'attributeChangedCallback',
].forEach(name => {
test(() => {
class C {
get [name]() { throw_rethrown_error(); }
}
assert_rethrown(() => {
customElements.define(`test-define-${name.toLowerCase()}-rethrow`, C);
});
}, `If constructor.prototype.${name} throws, should rethrow`);
[
{ name: 'undefined', value: undefined, success: true },
{ name: 'function', value: function () { }, success: true },
{ name: 'null', value: null, success: false },
{ name: 'object', value: {}, success: false },
{ name: 'integer', value: 1, success: false },
].forEach(data => {
test(() => {
class C { };
C.prototype[name] = data.value;
if (data.success) {
customElements.define(`test-define-${name.toLowerCase()}-${data.name}`, C);
} else {
assert_throws(expectTypeError, () => {
customElements.define(`test-define-${name.toLowerCase()}-${data.name}`, C);
});
}
}, `If constructor.prototype.${name} is ${data.name}, should ${data.success ? 'succeed' : 'throw a TypeError'}`);
});
});
})();
</script>
</body>