EncodeForRegExpEscape.js 2.0 KB

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  1. 'use strict';
  2. var NumberToString = require('./Number/toString');
  3. var StringIndexOf = require('./StringIndexOf');
  4. var StringPad = require('./StringPad');
  5. // var StringToCodePoints = require('./StringToCodePoints');
  6. var UnicodeEscape = require('./UnicodeEscape');
  7. var UTF16EncodeCodePoint = require('./UTF16EncodeCodePoint');
  8. var isLeadingSurrogate = require('../helpers/isLeadingSurrogate');
  9. var isTrailingSurrogate = require('../helpers/isTrailingSurrogate');
  10. var $TypeError = require('es-errors/type');
  11. var isCodePoint = require('../helpers/isCodePoint');
  12. var forEach = require('for-each');
  13. var regexTester = require('safe-regex-test');
  14. var isWhiteSpace = regexTester(/^\s$/);
  15. var isLineTerminator = regexTester(/^[\n\r\u2028\u2029]$/);
  16. // var punctuators = "(){}[]|,.?*+-^$=<>/#&!%:;@~'`\"\\"; // step 1
  17. var syntaxCharacter = '^$\\.*+?()[]{}|';
  18. var otherPunctuators = ",-=<>#&!%:;@~'`\""; // step 3
  19. // var toEscape = StringToCodePoints(otherPunctuators); // step 4
  20. var table64 = {
  21. '\u0009': 't',
  22. '\u000a': 'n',
  23. '\u000b': 'v',
  24. '\u000c': 'f',
  25. '\u000d': 'r',
  26. __proto__: null
  27. };
  28. module.exports = function EncodeForRegExpEscape(c) {
  29. if (!isCodePoint(c)) {
  30. throw new $TypeError('Assertion failed: `c` must be a valid Unicode code point');
  31. }
  32. var encoded = UTF16EncodeCodePoint(c);
  33. if (StringIndexOf(syntaxCharacter, encoded, 0) > -1 || encoded === '\u002F') { // step 1
  34. return '\\' + encoded; // step 1.a
  35. } else if (encoded in table64) { // step 2
  36. return '\\' + table64[encoded]; // step 2.a
  37. }
  38. if (
  39. StringIndexOf(otherPunctuators, encoded, 0) > -1
  40. || isWhiteSpace(encoded)
  41. || isLineTerminator(encoded)
  42. || isLeadingSurrogate(c)
  43. || isTrailingSurrogate(c)
  44. ) { // step 5
  45. if (c < 0xFF) { // step 5.a
  46. var hex = NumberToString(c, 16); // step 5.a.i
  47. return '\\x' + StringPad(hex, 2, '0', 'START'); // step 5.a.ii
  48. }
  49. var escaped = ''; // step 5.b
  50. var codeUnits = encoded; // step 5.c
  51. forEach(codeUnits, function (cu) { // step 5.d
  52. escaped += UnicodeEscape(cu); // step 5.d.i
  53. });
  54. return escaped; // step 5.e
  55. }
  56. return encoded; // step 6
  57. };