chore: refactor to remove mixin pattern (#81)

lib/index.js

@@ -63,8 +63,7 @@ const defaultRules = [
 // There may be others, but :?|<> are handled by node-tar
 const nameIsBadForWindows = file => /\*/.test(file)
 
-// a decorator that applies our custom rules to an ignore walker
-const npmWalker = Class => class Walker extends Class {
+class Walker extends IgnoreWalker {
   constructor (opt) {
     opt = opt || {}
 
@@ -397,11 +396,19 @@ const npmWalker = Class => class Walker extends Class {
   }
 
   sort (a, b) {
-    return sort(a, b)
+    // optimize for compressibility
+    // extname, then basename, then locale alphabetically
+    // https://twitter.com/isntitvacant/status/1131094910923231232
+    const exta = path.extname(a).toLowerCase()
+    const extb = path.extname(b).toLowerCase()
+    const basea = path.basename(a).toLowerCase()
+    const baseb = path.basename(b).toLowerCase()
+
+    return exta.localeCompare(extb, 'en') ||
+      basea.localeCompare(baseb, 'en') ||
+      a.localeCompare(b, 'en')
   }
-}
 
-class Walker extends npmWalker(IgnoreWalker) {
   globFiles (pattern, cb) {
     glob(pattern, { dot: true, cwd: this.path, nocase: true }, cb)
   }
@@ -430,19 +437,5 @@ const walk = (options, callback) => {
   return callback ? p.then(res => callback(null, res), callback) : p
 }
 
-// optimize for compressibility
-// extname, then basename, then locale alphabetically
-// https://twitter.com/isntitvacant/status/1131094910923231232
-const sort = (a, b) => {
-  const exta = path.extname(a).toLowerCase()
-  const extb = path.extname(b).toLowerCase()
-  const basea = path.basename(a).toLowerCase()
-  const baseb = path.basename(b).toLowerCase()
-
-  return exta.localeCompare(extb, 'en') ||
-    basea.localeCompare(baseb, 'en') ||
-    a.localeCompare(b, 'en')
-}
-
 module.exports = walk
 walk.Walker = Walker