Add StringCollection to make it easier to work with strings

tests/utils/string.collection.spec.ts

@@ -0,0 +1,54 @@
+import { expect } from 'chai';
+
+import { StringCollection } from '../../src/utils/string.collection';
+
+describe('StringCollection', () => {
+
+	let collection: StringCollection;
+
+	beforeEach(() => {
+		collection = new StringCollection();
+	});
+
+	it('should add item with value', () => {
+		collection.add('key', 'translation');
+		expect(collection.get('key')).to.equal('translation');
+	});
+
+	it('should add item with default value', () => {
+		collection.add('key');
+		expect(collection.get('key')).to.equal('');
+	});
+
+	it('should add array of items with default values', () => {
+		collection.add(['key', 'key2']);
+		expect(collection.count()).to.equal(2);
+	});
+
+	it('should remove item', () => {
+		collection.add('key1').add('key2').remove('key1');
+		expect(collection.count()).to.equal(1);
+	});
+
+	it('should return number of items', () => {
+		collection.add('key1').add('key2');
+		expect(collection.count()).to.equal(2);
+	});
+
+	it('should initialize with array of keys', () => {
+		const newCollection = StringCollection.fromArray(['Hello', 'World']);
+		expect(newCollection.count()).to.equal(2);
+	});
+
+	it('should initialize with key/value pairs', () => {
+		const newCollection = StringCollection.fromObject({'key': 'translation'});
+		expect(newCollection.get('key')).to.equal('translation');
+	});
+
+	it('should merge with other collection', () => {
+		collection.add('Hello');
+		const newCollection = StringCollection.fromArray(['World']);
+		expect(collection.merge(newCollection).count()).to.equal(2);
+	});
+
+});