parse.ts

import {isKebabCase, kebabCaseToCamelCase} from './utils'

/**
 * parse the LESS source, and extract variables in `#less-vars {...}`;
 * variable names should be kebab-case, and will be converted into camelCase
 * @param {string} source
 * @returns {object}
 */
export function parse(source: string): Record<string, string> {
	const vars: Record<string, string> = {}
	const m = source.replace(/[\r\n]/gm, ' ').match(/#less-vars\s*{([^{}]+)}/gm)
	if (m) {
		m.forEach((m) =>
			m
				.replace(/.*{|}.*/, '')
				.split(';')
				.forEach((kv) => {
					const i = kv.indexOf(':')
					if (i > 0) {
						const k = kv.substr(0, i).trim()
						const v = kv.substr(i + 1).trim()
						if (k.length > 0 && v.length > 0) {
							vars[k] = v
						}
					}
				}),
		)
	}

	const result: Record<string, string> = {}
	Object.entries(vars).forEach(([k, v]) => {
		if (!isKebabCase(k)) {
			throw new Error(`Less variable is not kebab-case: ${k}`)
		}
		result[kebabCaseToCamelCase(k)] = v
	})

	return result
}