case.js

import camelCase from 'lodash/camelCase';
import kebabCase from 'lodash/kebabCase';
import snakeCase from 'lodash/snakeCase';
import upperFirst from 'lodash/upperFirst';
import startCase from 'lodash/startCase';

export default ensureCase;

function ensureCase(raw = '', target = 'lowercase') {
	// We delete any content together with quotes because he can contains proper names (example `refactor: `Eslint` configuration`).
	// We need trim string because content with quotes can be at the beginning or end of a line
	const input = String(raw)
		.replace(/`.*?`|".*?"|'.*?'/g, '')
		.trim();
	const transformed = toCase(input, target);

	if (transformed === '' || transformed.match(/^\d/)) {
		return true;
	}

	return transformed === input;
}

function toCase(input, target) {
	switch (target) {
		case 'camel-case':
			return camelCase(input);
		case 'kebab-case':
			return kebabCase(input);
		case 'snake-case':
			return snakeCase(input);
		case 'pascal-case':
			return upperFirst(camelCase(input));
		case 'start-case':
			return startCase(input);
		case 'upper-case':
		case 'uppercase':
			return input.toUpperCase();
		case 'sentence-case':
		case 'sentencecase': {
			const [word] = input.split(' ');
			return `${toCase(word.charAt(0), 'upper-case')}${toCase(
				word.slice(1),
				'lower-case'
			)}${input.slice(word.length)}`;
		}
		case 'lower-case':
		case 'lowercase':
		case 'lowerCase': // Backwards compat config-angular v4
			return input.toLowerCase();
		default:
			throw new TypeError(`ensure-case: Unknown target case "${target}"`);
	}
}