refactor: replace prototype to class syntax (#4151)

Author: segayuu

lib/box/file.js

@@ -2,33 +2,35 @@
 
 const { readFile, readFileSync, stat, statSync } = require('hexo-fs');
 
-function File({ source, path, params, type }) {
-  this.source = source;
-  this.path = path;
-  this.params = params;
-  this.type = type;
-}
-
-File.prototype.read = function(options, callback) {
-  return readFile(this.source, options).asCallback(callback);
-};
+class File {
+  constructor({ source, path, params, type }) {
+    this.source = source;
+    this.path = path;
+    this.params = params;
+    this.type = type;
+  }
 
-File.prototype.readSync = function(options) {
-  return readFileSync(this.source, options);
-};
+  read(options, callback) {
+    return readFile(this.source, options).asCallback(callback);
+  }
 
-File.prototype.stat = function(options, callback) {
-  if (!callback && typeof options === 'function') {
-    callback = options;
-    options = {};
+  readSync(options) {
+    return readFileSync(this.source, options);
   }
 
-  return stat(this.source).asCallback(callback);
-};
+  stat(options, callback) {
+    if (!callback && typeof options === 'function') {
+      callback = options;
+      options = {};
+    }
 
-File.prototype.statSync = function(options) {
-  return statSync(this.source);
-};
+    return stat(this.source).asCallback(callback);
+  }
+
+  statSync(options) {
+    return statSync(this.source);
+  }
+}
 
 File.TYPE_CREATE = 'create';
 File.TYPE_UPDATE = 'update';