Initial Commit

Signed-off-by: Richie Bendall <richiebendall@gmail.com>

.editorconfig

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+root = true
+
+[*]
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = tab
+
+[*.yml]
+indent_style = space
+indent_size = 2

.gitattributes

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-# Auto detect text files and perform LF normalization
-* text=auto
+* text=auto eol=lf

.github/workflows/main.yml

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+name: CI
+on:
+  - push
+  - pull_request
+jobs:
+  test:
+    name: Node.js ${{ matrix.node-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version:
+          - 18
+          - 16
+          - 14
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm install
+      - run: npm test

.gitignore

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+node_modules
+package-lock.json
+yarn.lock

.npmrc

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+package-lock=false

index.d.ts

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+import type {ValueOf} from 'type-fest';
+
+type EventListenerOrEventListenerObject<Value extends Event | CustomEvent> = (value: Value) => void | {
+	handleEvent(value: Value): void;
+};
+
+/**
+Strictly typed definitions for [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget)
+
+Only used for type-checking; compiles to no code.
+
+@example
+```
+import type StrictEventTarget from 'strict-event-target';
+
+const target = new (EventTarget as typeof StrictEventTarget<{
+	foo: string; // Event with data
+}, [
+	'bar', // Event without data
+]>);
+
+target.dispatchEvent(new CustomEvent('foo', {detail: 'The'}));
+
+target.dispatchEvent(new Event('bar'));
+```
+
+@example
+```
+import type StrictEventTarget from 'strict-event-target';
+
+class Foo extends (EventTarget as typeof StrictEventTarget<{
+	foo: string; // Event with data
+}, [
+	'bar', // Event without data
+]>) {}
+```
+*/
+export default class StrictEventTarget<EventsWithData extends Record<string, unknown> = {}, EventsWithoutData extends string[] = []> implements EventTarget { // eslint-disable-line @typescript-eslint/ban-types
+	addEventListener<Name extends keyof EventsWithData>(name: Name, callback: EventListenerOrEventListenerObject<CustomEvent<EventsWithData[Name]>> | null, options?: AddEventListenerOptions | boolean): void; // eslint-disable-line @typescript-eslint/ban-types
+	addEventListener<Name extends ValueOf<EventsWithoutData>>(name: Name, callback: EventListenerOrEventListenerObject<Event> | null, options?: AddEventListenerOptions | boolean): void; // eslint-disable-line @typescript-eslint/ban-types
+
+	dispatchEvent(event: Event | CustomEvent<ValueOf<EventsWithData>>): boolean;
+
+	removeEventListener<Name extends keyof EventsWithData>(name: Name, callback: EventListenerOrEventListenerObject<CustomEvent<EventsWithData[Name]>> | null, options?: EventListenerOptions | boolean): void; // eslint-disable-line @typescript-eslint/ban-types
+	removeEventListener<Name extends ValueOf<EventsWithoutData>>(name: Name, callback: EventListenerOrEventListenerObject<Event> | null, options?: EventListenerOptions | boolean): void; // eslint-disable-line @typescript-eslint/ban-types
+}

index.test-d.ts

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+import type StrictEventTarget from './index.js';
+
+type EventsWithData = {
+	a: string;
+};
+
+type EventsWithoutData = ['b'];
+
+const target: StrictEventTarget<EventsWithData, EventsWithoutData> = new (EventTarget as typeof StrictEventTarget<EventsWithData, EventsWithoutData>)();
+
+function aCallback(_event: CustomEvent<string>) {} // eslint-disable-line @typescript-eslint/no-empty-function
+function bCallback(_event: Event) {} // eslint-disable-line @typescript-eslint/no-empty-function
+
+target.addEventListener('a', aCallback);
+target.addEventListener('b', bCallback);
+
+target.dispatchEvent(new CustomEvent('a', {detail: 'foo'}));
+target.dispatchEvent(new Event('b'));
+
+target.removeEventListener('a', aCallback);
+target.removeEventListener('b', bCallback);

license

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+MIT License
+
+Copyright (c) 2022 Richie Bendall
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

package.json

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+{
+	"name": "strict-event-target",
+	"version": "0.0.0",
+	"description": "Strictly typed definitions for EventTarget",
+	"license": "MIT",
+	"repository": "Richienb/strict-event-target",
+	"author": {
+		"name": "Richie Bendall",
+		"email": "richiebendall@gmail.com"
+	},
+	"type": "module",
+	"types": "index.d.ts",
+	"engines": {
+		"node": ">=14"
+	},
+	"scripts": {
+		"test": "xo && tsd"
+	},
+	"files": [
+		"index.d.ts"
+	],
+	"keywords": [
+		"EventTarget",
+		"TypeScript"
+	],
+	"dependencies": {
+		"type-fest": "^3.0.0"
+	},
+	"devDependencies": {
+		"@sindresorhus/tsconfig": "^3.0.1",
+		"tsd": "^0.24.1",
+		"typescript": "^4.8.3",
+		"xo": "^0.52.3"
+	}
+}

readme.md

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+# strict-event-target
+
+> Strictly typed definitions for [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget)
+
+Only used for type-checking; compiles to no code.
+
+## Install
+
+```sh
+npm install strict-event-target
+```
+
+## Usage
+
+```ts
+import type StrictEventTarget from 'strict-event-target';
+
+const target = new (EventTarget as typeof StrictEventTarget<{
+	foo: string; // Event with data
+}, [
+	'bar', // Event without data
+]>);
+
+target.dispatchEvent(new CustomEvent('foo', {detail: 'The'}));
+
+target.dispatchEvent(new Event('bar'));
+```
+
+```ts
+import type StrictEventTarget from 'strict-event-target';
+
+class Foo extends (EventTarget as typeof StrictEventTarget<{
+	foo: string; // Event with data
+}, [
+	'bar', // Event without data
+]>) {}
+```
+
+## API
+
+### StrictEventTarget<EventsWithData?, EventsWithoutData?>
+
+#### EventsWithData
+
+Type: `Record<string, unknown>`\
+Default: `{}`
+
+Events that will be created with [`CustomEvent`](https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent), thus being able to contain custom data.
+
+#### EventsWithoutData
+
+Type: `string[]`\
+Default: `[]`
+
+Events that will be created with [`Event`](https://developer.mozilla.org/en-US/docs/Web/API/Event).

tsconfig.json

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+{
+	"extends": "@sindresorhus/tsconfig"
+}