split-by-upper-case.js

// examples:
//   makePermissionDescription'oneTwoThree') == 'one two three'
//   makePermissionDescription('hasFooBarXYZ') == 'foo bar XYZ'
//   makePermissionDescription('isFOOBar') == 'is FOO bar'
// Note: output is meaningful only for inputs that consists only of letters
const splitByUpperCase = keyName => {
	const words = [];

	let desc = keyName.replace(/^can/, '');
	let loops = 4096;
	while (loops-- > 0) {
		const m = desc.slice(1).match(/[A-Z]+/);

		if (!m || m[0].length == desc.length - 1) {
			if (!(desc[1] || '').match(/[A-Z]/)) {
				desc = desc.toLowerCase();
			}
			words.push(desc);
			break;
		}

		const i = m.index == 0 ? m[0].length : m.index + 1;
		let word = desc.slice(0, i);
		if (!(word[1] || '').match(/[A-Z]/)) {
			word = word.toLowerCase();
		}
		words.push(word);
		desc = desc.slice(i);
	}

	return words.join(' ');
};