feat: add constructor param to extend/override the accent map

README.md

@@ -75,6 +75,25 @@ Use the 3d argument to specify the wrapping html tag (strong, em, span etc.):
 af.highlightMatch('Fulanilo López', 'lo', 'strong'); // --> "Fulani<strong>lo</strong> <strong>Ló</strong>pez"
 ```
 
+
+## Extending and Overriding the Accent Map
+
+The `AccentFolding` class allows you to extend or override the default accent map by providing a custom map to the constructor.
+
+### Extending the Accent Map
+
+To extend the accent map with new mappings, pass an object with the new mappings to the constructor. For example:
+
+```js
+import AccentFolding from './accentFolding.js';
+
+const customAccentMap = { 'ö': 'oe', '✝': 't' };
+const accentFolder = new AccentFolding(customAccentMap);
+
+console.log(accentFolder.replace('Föhn')); // Outputs: Foehn
+console.log(accentFolder.replace('✝illa')); // Outputs: tilla
+```
+
 ## Requirements
 
 Node.js version 14.7 or higher

src/accentFolding.js

@@ -4,11 +4,17 @@ class AccentFolding {
 	#cache;
 	#accentMap;
 
-	constructor() {
+	constructor(newMap = null) {
+		if (newMap !== null && typeof newMap !== 'object') {
+			throw new TypeError('newMap must be an object');
+		}
 		this.#accentMap = new Map([
 			...AccentFolding.convertAccentMapToArray(defaultAccentMap),
 		]);
 		this.#cache = new Map();
+		if (newMap) {
+			this.#extendAccentMap(newMap);
+		}
 	}
 
 	#fold(s) {
@@ -78,6 +84,13 @@ class AccentFolding {
 	static convertAccentMapToArray(accentMap) {
 		return Object.entries(accentMap);
 	}
+
+	#extendAccentMap(newMap) {
+		for (const [key, value] of Object.entries(newMap)) {
+			this.#accentMap.set(key, value);
+		}
+		this.#cache.clear(); // Clear cache to ensure new mappings are used
+	}
 }
 
 export default AccentFolding;

src/accentFolding.js.test.js

@@ -120,4 +120,26 @@ describe('AccentFolding', () => {
 			expect(accentFolder.replace('')).toBe('');
 		});
 	});
+
+	describe('constructor', () => {
+		it('should initialize with default accent map', () => {
+			expect(accentFolder.replace('á')).toBe('a');
+		});
+
+		it('should extend the accent map with new mappings if provided', () => {
+			const customAccentFolder = new AccentFolding({ ö: 'oe', '✝': 't' });
+			expect(customAccentFolder.replace('Föhn')).toBe('Foehn');
+			expect(customAccentFolder.replace('✝illa')).toBe('tilla');
+		});
+
+		it('should override existing mappings if provided', () => {
+			const customAccentFolder = new AccentFolding({ á: 'aa' });
+			expect(customAccentFolder.replace('á')).toBe('aa');
+		});
+
+		it('should throw TypeError if newMap is not an object', () => {
+			expect(() => new AccentFolding(123)).toThrow(TypeError);
+			expect(() => new AccentFolding(123)).toThrow('newMap must be an object');
+		});
+	});
 });