refactor: extract regexp

Author: dukeluo

lib/constants/regex.js

@@ -9,6 +9,12 @@
  */
 const PREFINED_MATCH_SYNTAX_REGEXP = /^<(\d+)>$/;
 
+/**
+ * @example C:\
+ */
+const WINDOWS_DRIVE_LETTER_REGEXP = /^[A-Za-z]:\\/;
+
 module.exports = {
   PREFINED_MATCH_SYNTAX_REGEXP,
+  WINDOWS_DRIVE_LETTER_REGEXP,
 };

lib/utils/filename.js

@@ -6,6 +6,7 @@
 
 const path = require('path');
 const { pipe, isNotEmpty } = require('./utility');
+const { WINDOWS_DRIVE_LETTER_REGEXP } = require('../constants/regex');
 
 /**
  * @returns {string} filename without path
@@ -82,7 +83,7 @@ const toPosixPath = (p) => p.split(path.sep).join(path.posix.sep);
  * @returns {string} file path without drive letter on windows
  * @param {string} p file path on windows
  */
-const removeDriveLetter = (p) => p.replace(/^[A-Za-z]:\\/, '');
+const removeDriveLetter = (p) => p.replace(WINDOWS_DRIVE_LETTER_REGEXP, '');
 
 /** @typedef {module:eslint} ESLint */
 /**