elastic-apm-node/lib/wildcard-matcher.js

The official Elastic APM agent for Node.js

/*
 * Copyright Elasticsearch B.V. and other contributors where applicable.
 * Licensed under the BSD 2-Clause License; you may not use this file except in
 * compliance with the BSD 2-Clause License.
 */

'use strict';
/**
 * Implements a Wildcard matcher
 *
 * Exports a function that implements a simple wildcard matcher
 * per: https://github.com/elastic/apm/issues/144
 */
const escapeStringRegexp = require('escape-string-regexp');

// Converts elastic-wildcard pattern into a
// a javascript regular expression.
const starMatchToRegex = (pattern) => {
  // case insensative by default
  let regexOpts = ['i'];
  if (pattern.startsWith('(?-i)')) {
    regexOpts = [];
    pattern = pattern.slice(5);
  }

  const patternLength = pattern.length;
  const reChars = ['^'];
  for (let i = 0; i < patternLength; i++) {
    const char = pattern[i];
    switch (char) {
      case '*':
        reChars.push('.*');
        break;
      default:
        reChars.push(escapeStringRegexp(char));
    }
  }
  reChars.push('$');
  return new RegExp(reChars.join(''), regexOpts.join(''));
};

class WildcardMatcher {
  compile(pattern) {
    return starMatchToRegex(pattern);
  }

  match(string, pattern) {
    const re = this.compile(pattern);
    return string.search(re) !== -1;
  }
}
module.exports = { WildcardMatcher };