Add Error.isError & fix arr.uniqueBy

CHANGELOG.md

@@ -7,6 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [v0.4.4] - 2024-10-09
+
+### Added
+- Add `Error.isError` (imperfect, but works)
+
+### Fixed
+- Fixed and simplicy `Array.prototype.uniqueBy`
+
 ## [v0.4.3] - 2024-09-17
 
 ### Added

array.js

@@ -190,41 +190,32 @@ if (! (Array.prototype.equals instanceof Function)) {
  */
 if (! (Array.prototype.uniqueBy instanceof Function)) {
 	Array.prototype.uniqueBy = function uniqueBy(arg) {
-		if (typeof arg === 'undefined') {
-			return [...new Set(this)];
-		} else if (typeof arg === 'string') {
-			const found = [];
-
-			return this.filter(obj => {
-				const key = obj[arg];
-				if (found.includes(key)) {
-					return false;
-				} else {
-					found.push(key);
-					return true;
-				}
-			});
-		} else if (arg instanceof Function) {
-			const found = [];
+		switch (typeof arg) {
+			case 'undefined':
+				return [...new Set(this)];
 
-			return this.filter((...args) => {
-				try {
+			case 'string':
+			case 'number':
+			case 'symbol':
+				return this.uniqueBy(entry => entry[arg]);
+
+			case 'function': {
+				const found = new Set(); //Cannot use `WeakSet` in case of primative values
+
+				return this.filter((...args) => {
 					const key = arg.apply(this, args);
 
-					if (typeof key !== 'string') {
-						return false;
-					} else if (found.includes(key)) {
+					if (found.has(key)) {
 						return false;
 					} else {
-						found.push(key);
+						found.add(key);
 						return true;
 					}
-				} catch {
-					return false;
-				}
-			});
-		} else {
-			throw new TypeError('Not a valid argument for uniqueBy');
+				});
+			}
+
+			default:
+				throw new TypeError('Not a valid argument for uniqueBy');
 		}
 	};
 }

errors.js

@@ -19,3 +19,13 @@ if (! (globalThis.reportError instanceof Function)) {
 		globalThis.dispatchEvent(errorToEvent(error));
 	};
 }
+
+
+if (! (Error.isError instanceof Function)) {
+	// @see https://github.com/tc39/proposal-is-error/blob/main/polyfill.js
+	const toStr = Function.bind.call(Function.call, Object.prototype.toString);
+
+	Error.isError = function isError(arg) {
+		return arg instanceof Error || (typeof arg === 'object' && toStr(arg) === '[object Error]' && arg[Symbol.toStringTag] === undefined);
+	};
+}

eslint.config.js

@@ -1,9 +1,3 @@
-import { ignoreFile } from '@shgysk8zer0/eslint-config/ignoreFile.js';
-import browser from '@shgysk8zer0/eslint-config/browser.js';
+import { browser } from '@shgysk8zer0/eslint-config';
 
-export default [
-	ignoreFile,
-	browser({
-		ignores: ['**/*.min.js', '**/*.cjs', 'assets/dedent.js','assets/url-pattern.js'],
-	}),
-];
+export default browser({ ignores: ['**/*.min.js', '**/*.cjs', 'assets/dedent.js','assets/url-pattern.js'] });

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@shgysk8zer0/polyfills",
-  "version": "0.4.3",
+  "version": "0.4.4",
   "private": false,
   "type": "module",
   "description": "A collection of JavaScript polyfills",