add getDynamicConfig function

index.js

@@ -1,8 +1,12 @@
 /* 基础小工具，可通用于服务端和用户端
  */
 
+const fs = require('fs')
+const path = require('path')
+
 module.exports = {
   sleep: (ms) => new Promise((resolve, reject) => setTimeout(resolve, ms)),
+
   parseJsonPossible(value) {
     try {
       return JSON.parse(value)
@@ -10,6 +14,7 @@ module.exports = {
       return value
     }
   },
+
   sortAndFilterJson({ fields, entity, exclude = [] } = {}) {
     const newEntity = {}
     for (let key of Object.keys(fields).sort()) {
@@ -22,4 +27,15 @@ module.exports = {
     }
     return JSON.stringify(newEntity)
   },
+
+  getDynamicConfig(dynamicConfigFile='ConfigDynamic.js') { // dynamicConfigFile should be absolute or relative to the node process's dir.
+    const fullpath = path.join(process.cwd(), dynamicConfigFile)
+    if (fs.existsSync(fullpath)) {
+      delete require.cache[require.resolve(fullpath)] // delete require.cache[fullpath] 不起作用
+      return require(fullpath)
+    } else {
+      return {}
+    }
+  },
+
 }