An convenience method for converting to and from different casing types.

toCase.js

if (!String.prototype.toCase) {
	Object.defineProperties(String.prototype, {
		'toCase': {
			value: function(type = 'camel') {

				const seperators = {
					'camel': '',
					'pascal': '',
					'snake': '_',
					'domain': '.',
					'kebab': '-'
				};

				if (Object.keys(seperators).indexOf(type) == -1) {
					throw new TypeError('Type must either be `camel`, `pascal`, `snake`, `domain` or `kebab`');
				}
		
				let parts = this.split(/(?=[A-Z])|_|-| |\./)
					.map((key, idx) => {
						switch (type) {
						case 'camel':
							if (idx == 0) return key.toLowerCase();
							// falls through
						case 'pascal':
							return key.charAt(0).toUpperCase() + key.substring(1).toLowerCase();
						case 'domain':
							// falls through
						case 'kebab':
							// falls through
						case 'snake':
							return key.toLowerCase();
						}
					});

				return parts.join(seperators[type]);
								
			}
		}
	});
}