Migrate to TypeScript and use Map (#99)

Migrate to TypeScript & Microbundle, move to Map for event handler storage

Author: jackfranklin

README.md

@@ -95,57 +95,57 @@ const emitter: mitt.Emitter = mitt();
 
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### mitt
+#### Table of Contents
 
-Mitt: Tiny (~200b) functional event emitter / pubsub.
+-   [mitt](#mitt)
+-   [on](#on)
+    -   [Parameters](#parameters)
+-   [off](#off)
+    -   [Parameters](#parameters-1)
+-   [emit](#emit)
+    -   [Parameters](#parameters-2)
 
-**Parameters**
+### mitt
 
--   `all` **EventHandlerMap** 
+Mitt: Tiny (~200b) functional event emitter / pubsub.
 
 Returns **Mitt** 
 
 ### on
 
 Register an event handler for the given type.
 
-**Parameters**
+#### Parameters
 
--   `type` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Type of event to listen for, or `"*"` for all events
+-   `type` **([string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) \| [symbol](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Symbol))** Type of event to listen for, or `"*"` for all events
 -   `handler` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** Function to call in response to given event
 
 ### off
 
 Remove an event handler for the given type.
 
-**Parameters**
+#### Parameters
 
--   `type` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Type of event to unregister `handler` from, or `"*"`
+-   `type` **([string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) \| [symbol](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Symbol))** Type of event to unregister `handler` from, or `"*"`
 -   `handler` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** Handler function to remove
 
 ### emit
 
 Invoke all handlers for the given type.
 If present, `"*"` handlers are invoked after type-matched handlers.
 
-_Note: Manually firing "*" handlers is not supported._
+Note: Manually firing "\*" handlers is not supported.
 
-**Parameters**
+#### Parameters
 
--   `type` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** The event type to invoke
+-   `type` **([string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) \| [symbol](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Symbol))** The event type to invoke
 -   `evt` **Any?** Any value (object is recommended and powerful), passed to each handler
 
 ## Contribute
 
 First off, thanks for taking the time to contribute!
 Now, take a moment to be sure your contributions make sense to everyone else.
 
-Development Start:
-
-This project is typed with Flow Type annotations. To ensure you have the proper typings for this project run
-
-`flow-typed install`
-
 ### Reporting Issues
 
 Found a problem? Want a new feature? First of all see if your issue or idea has [already been reported](../../issues).

mitt.d.ts

@@ -3,20 +3,20 @@
   "version": "1.2.0",
   "description": "Tiny 200b functional Event Emitter / pubsub.",
   "jsnext:main": "dist/mitt.es.js",
+  "source": "src/index.ts",
   "module": "dist/mitt.es.js",
   "main": "dist/mitt.js",
   "umd:main": "dist/mitt.umd.js",
+  "typings": "dist/index.d.ts",
   "scripts": {
     "bump": "standard-version",
-    "testonly": "mocha --require esm --require flow-remove-types/register test/**/*.js",
-    "lint": "eslint src test",
-    "test": "flow && npm run lint && npm run testonly",
-    "build": "npm-run-all --silent clean -p rollup -p minify:* -s docs size",
+    "testonly": "mocha --require esm --require ts-node/register test/**/*.js",
+    "lint": "eslint src test --ext ts --ext js",
+    "test": "tsc src/index.ts --noEmit && npm run lint && npm run testonly",
+    "bundle": "microbundle",
+    "build": "npm-run-all --silent clean -p bundle -s docs size",
     "clean": "rimraf dist",
-    "rollup": "rollup -c",
-    "minify:cjs": "uglifyjs $npm_package_main -cm toplevel -o $npm_package_main -p relative --in-source-map ${npm_package_main}.map --source-map ${npm_package_main}.map",
-    "minify:umd": "uglifyjs $npm_package_umd_main -cm -o $npm_package_umd_main -p relative --in-source-map ${npm_package_umd_main}.map --source-map ${npm_package_umd_main}.map",
-    "docs": "documentation readme src/index.js --section API -q",
+    "docs": "documentation readme src/index.ts --section API -q --parse-extension ts",
     "size": "echo \"Gzipped Size: $(strip-json-comments --no-whitespace $npm_package_main | gzip-size | pretty-bytes)\"",
     "release": "npm run build -s && npm run bump && git push --follow-tags origin master && npm publish"
   },
@@ -33,21 +33,15 @@
   "license": "MIT",
   "files": [
     "src",
-    "dist",
-    "mitt.d.ts"
+    "dist"
   ],
-  "babel": {
-    "presets": [
-      "es2015",
-      "stage-0"
-    ],
-    "plugins": [
-      "transform-flow-strip-types"
-    ]
-  },
   "eslintConfig": {
-    "extends": "eslint:recommended",
-    "parser": "babel-eslint",
+    "extends": [
+      "eslint:recommended",
+      "plugin:@typescript-eslint/eslint-recommended",
+      "plugin:@typescript-eslint/recommended"
+    ],
+    "parser": "@typescript-eslint/parser",
     "parserOptions": {
       "sourceType": "module"
     },
@@ -63,34 +57,30 @@
       "semi": [
         2,
         "always"
-      ]
+      ],
+      "@typescript-eslint/no-explicit-any": 0,
+      "@typescript-eslint/explicit-function-return-type": 0,
+      "@typescript-eslint/no-empty-function": 0
     }
   },
-  "typings": "./mitt.d.ts",
   "devDependencies": {
-    "babel-core": "^6.9.1",
-    "babel-eslint": "^10.0.3",
-    "babel-plugin-transform-flow-strip-types": "^6.21.0",
-    "babel-preset-es2015": "^6.9.0",
-    "babel-preset-stage-0": "^6.5.0",
+    "@typescript-eslint/eslint-plugin": "^2.34.0",
+    "@typescript-eslint/parser": "^2.34.0",
     "chai": "^3.5.0",
-    "documentation": "^4.0.0-beta4",
+    "documentation": "^13.0.0",
     "eslint": "^6.5.1",
     "esm": "^3.2.25",
-    "flow-bin": "^0.38.0",
-    "flow-remove-types": "^1.2.0",
     "gzip-size-cli": "^1.0.0",
+    "microbundle": "^0.12.0",
     "mocha": "^3.2.0",
     "npm-run-all": "^2.1.1",
     "pretty-bytes-cli": "^2.0.0",
     "rimraf": "^2.5.2",
-    "rollup": "^0.41.4",
-    "rollup-plugin-buble": "^0.15.0",
-    "rollup-plugin-flow": "^1.1.1",
     "sinon": "^1.17.4",
     "sinon-chai": "^2.8.0",
     "standard-version": "^4.0.0",
     "strip-json-comments-cli": "^1.0.1",
-    "uglify-js": "^2.6.2"
+    "ts-node": "^8.10.1",
+    "typescript": "^3.9.3"
   }
 }

package.json

@@ -0,0 +1,75 @@
+type EventType = string | symbol;
+
+// An event handler can take an optional event argument
+// and should not return a value
+type Handler = (event?: any) => void;
+type WildcardHandler= (type: EventType, event?: any) => void
+
+// An array of all currently registered event handlers for a type
+type EventHandlerList = Array<Handler>;
+type WildCardEventHandlerList = Array<WildcardHandler>;
+
+// A map of event types and their corresponding event handlers.
+type EventHandlerMap = Map<EventType, EventHandlerList | WildCardEventHandlerList>;
+
+export interface Emitter {
+	on(type: EventType, handler: Handler): void;
+	on(type: "*", handler: WildcardHandler): void;
+
+	off(type: EventType, handler: Handler): void;
+	off(type: "*", handler: WildcardHandler): void;
+
+	emit<T = any>(type: EventType, event?: T): void;
+	emit(type: "*", event?: any): void;
+}
+
+/** Mitt: Tiny (~200b) functional event emitter / pubsub.
+ *  @name mitt
+ *  @returns {Mitt}
+ */
+export default function mitt(all: EventHandlerMap): Emitter {
+	all = all || new Map();
+
+	return {
+		/**
+		 * Register an event handler for the given type.
+		 *
+		 * @param {string|symbol} type Type of event to listen for, or `"*"` for all events
+		 * @param {Function} handler Function to call in response to given event
+		 * @memberOf mitt
+		 */
+		on(type: EventType, handler: Handler) {
+			const handlers = (all.get(type) || []);
+			handlers.push(handler);
+			all.set(type, handlers);
+		},
+
+		/**
+		 * Remove an event handler for the given type.
+		 *
+		 * @param {string|symbol} type Type of event to unregister `handler` from, or `"*"`
+		 * @param {Function} handler Handler function to remove
+		 * @memberOf mitt
+		 */
+		off(type: EventType, handler: Handler) {
+			if (all.has(type)) {
+				all.get(type).splice(all.get(type).indexOf(handler) >>> 0, 1);
+			}
+		},
+
+		/**
+		 * Invoke all handlers for the given type.
+		 * If present, `"*"` handlers are invoked after type-matched handlers.
+		 *
+		 * Note: Manually firing "*" handlers is not supported.
+		 *
+		 * @param {string|symbol} type The event type to invoke
+		 * @param {Any} [evt] Any value (object is recommended and powerful), passed to each handler
+		 * @memberOf mitt
+		 */
+		emit(type: EventType, evt: any) {
+			((all.get(type) || []) as EventHandlerList).slice().map((handler) => { handler(evt); });
+			((all.get('*') || []) as WildCardEventHandlerList).slice().map((handler) => { handler(type, evt); });
+		}
+	};
+}