1 files changed, 87 insertions, 0 deletions
diff --git a/packages/webapi/test/elements.js b/packages/webapi/test/elements.js
new file mode 100644
index 000000000..5d7501592
--- /dev/null
+++ b/packages/webapi/test/elements.js
@@ -0,0 +1,87 @@
+import { assert, test } from '../run/test.setup.js'
+import { polyfill } from '../mod.js'
+
+test(() => {
+	return [
+		{
+			name: 'Includes Custom Element functionality',
+			test() {
+				const target = {}
+
+				polyfill(target)
+
+				assert.equal(Reflect.has(target, 'CustomElementRegistry'), true)
+				assert.equal(Reflect.has(target, 'customElements'), true)
+				assert.equal(Reflect.has(target, 'HTMLElement'), true)
+			},
+		},
+		{
+			name: 'Supports Custom Element creation',
+			test() {
+				const target = {}
+
+				polyfill(target)
+
+				const CustomElement = class HTMLCustomElement extends target.HTMLElement {}
+
+				target.customElements.define('custom-element', CustomElement)
+
+				assert.equal(target.customElements.get('custom-element'), CustomElement)
+				assert.equal(target.customElements.getName(CustomElement), 'custom-element')
+			},
+		},
+		{
+			name: 'Supports Custom Elements created from Document',
+			test() {
+				const target = {}
+
+				polyfill(target)
+
+				assert.equal(target.document.body.localName, 'body')
+				assert.equal(target.document.body.tagName, 'BODY')
+
+				assert.equal(target.document.createElement('custom-element').constructor.name, 'HTMLUnknownElement')
+
+				const CustomElement = class HTMLCustomElement extends target.HTMLElement {}
+
+				target.customElements.define('custom-element', CustomElement)
+
+				assert.equal(target.document.createElement('custom-element').constructor.name, 'HTMLCustomElement')
+			},
+		},
+		{
+			name: 'Supports Custom Elements with properties',
+			test() {
+				const target = {}
+
+				polyfill(target)
+
+				const testSymbol = Symbol.for('webapi.test')
+
+				const CustomElement = class HTMLCustomElement extends target.HTMLElement {
+					otherMethod = () => testSymbol
+
+					method() {
+						return this.otherMethod()
+					}
+
+					static method() {
+						return this.otherMethod()
+					}
+
+					static otherMethod() {
+						return testSymbol
+					}
+				}
+
+				target.customElements.define('custom-element', CustomElement)
+
+				assert.equal(CustomElement.method(), testSymbol)
+
+				const customElement = new CustomElement()
+
+				assert.equal(customElement.method(), testSymbol)
+			},
+		},
+	]
+})