stylelint/src/utils/functionArgumentsSearch.js

Modern CSS linter

import balancedMatch from "balanced-match"
import styleSearch from "./styleSearch"

/**
 * Search a CSS string for functions by name.
 * For every match, invoke the callback, passing the function's
 * "argument(s) string" (whatever is inside the parentheses)
 * as an argument.
 *
 * @param {string} source
 * @param {string} functionName - e.g. calc, color, rgba
 * @param {function} callback - Will be called once for every
 *   matching function found, with the function's "argument(s) string"
 *   and its starting index as the arguments
 */
export default function (source, functionName, callback) {
  styleSearch({ source, target: functionName, checkFunctionNames: true }, match => {
    if (source[match.endIndex] !== "(") { return }
    const parensMatch = balancedMatch("(", ")", source.substr(match.startIndex))
    callback(parensMatch.body, match.endIndex + 1)
  })
}