微信小程序中使用lodash

探究过程

不想看探究过程的, 结论在最后.

• 安装 lodash.get, 拷贝文件node_modules/lodash.get/index.js至 utils/lodash.get/index.js, 然后直接 require('./utils/lodash.get/index.js'), 可以正常使用

• 拷贝 node_modules/lodash/lodash.js 文件至 utils/lodash/lodash.js, 然后直接 require('./utils/lodash/lodash.js'), 出现

Uncaught TypeError: Cannot read property 'prototype' of undefined

跳转至源码 发现 Array 不存在, 因为 freeGlobal 和 freeSelf 都为 false, 因为微信直接注入了 window 和 self;

最终, Array = (Function('return this')()).Array 为 undefined.

所以, 只需要替换 root 的值即可, 从lodash的源码中发现, lodash 会pick以下属性

使用try catch 监测支持属性

try { root.Array = Array } catch (e) { console.log('Array not support in MINA, skip') }
try { root.Buffer = Buffer } catch (e) { console.log('Buffer not support in MINA, skip') }
try { root.DataView = DataView } catch (e) { console.log('DataView not support in MINA, skip') }
try { root.Date = Date } catch (e) { console.log('Date not support in MINA, skip') }
try { root.Error = Error } catch (e) { console.log('Error not support in MINA, skip') }
try { root.Float32Array = Float32Array } catch (e) { console.log('Float32Array not support in MINA, skip') }
try { root.Float64Array = Float64Array } catch (e) { console.log('Float64Array not support in MINA, skip') }
try { root.Function = Function } catch (e) { console.log('Function not support in MINA, skip') }
try { root.Int8Array = Int8Array } catch (e) { console.log('Int8Array not support in MINA, skip') }
try { root.Int16Array = Int16Array } catch (e) { console.log('Int16Array not support in MINA, skip') }
try { root.Int32Array = Int32Array } catch (e) { console.log('Int32Array not support in MINA, skip') }
try { root.Map = Map } catch (e) { console.log('Map not support in MINA, skip') }
try { root.Math = Math } catch (e) { console.log('Math not support in MINA, skip') }
try { root.Object = Object } catch (e) { console.log('Object not support in MINA, skip') }
try { root.Promise = Promise } catch (e) { console.log('Promise not support in MINA, skip') }
try { root.RegExp = RegExp } catch (e) { console.log('RegExp not support in MINA, skip') }
try { root.Set = Set } catch (e) { console.log('Set not support in MINA, skip') }
try { root.String = String } catch (e) { console.log('String not support in MINA, skip') }
try { root.Symbol = Symbol } catch (e) { console.log('Symbol not support in MINA, skip') }
try { root.TypeError = TypeError } catch (e) { console.log('TypeError not support in MINA, skip') }
try { root.Uint8Array = Uint8Array } catch (e) { console.log('Uint8Array not support in MINA, skip') }
try { root.Uint8ClampedArray = Uint8ClampedArray } catch (e) { console.log('Uint8ClampedArray not support in MINA, skip') }
try { root.Uint16Array = Uint16Array } catch (e) { console.log('Uint16Array not support in MINA, skip') }
try { root.Uint32Array = Uint32Array } catch (e) { console.log('Uint32Array not support in MINA, skip') }
try { root.WeakMap = WeakMap } catch (e) { console.log('WeakMap not support in MINA, skip') }
try { root._ = _ } catch (e) { console.log('_ not support in MINA, skip') }
try { root.clearTimeout = clearTimeout } catch (e) { console.log('clearTimeout not support in MINA, skip') }
try { root.isFinite = isFinite } catch (e) { console.log('isFinite not support in MINA, skip') }
try { root.parseInt = parseInt } catch (e) { console.log('parseInt not support in MINA, skip') }
try { root.setTimeout = setTimeout } catch (e) { console.log('setTimeout not support in MINA, skip') }

在微信Android中测试后, 发现小程序不支持以下属性

结论

① 直接引入 lodash modularize 之后的包可以解决

  npm install lodash.get
  let get = require('./your_copy_path/lodash.get/index');
  // 直接使用 get(obj, path);

② 将lodash4.16.6 lodash/lodash.js:416 中

    ```js
    var root = freeGlobal || freeSelf || Function('return this')();
    ```   

替换为

 var root = {
   Array: Array,
   Date: Date,
   Error: Error,
   Function: Function,
   Math: Math,
   Object: Object,
   RegExp: RegExp,
   String: String,
   TypeError: TypeError,
   setTimeout: setTimeout,
   clearTimeout: clearTimeout,
   setInterval: setInterval,
   clearInterval: clearInterval
 };

3️⃣ 如果每次修改嫌麻烦, 可以使用脚本控制
也可以尝试 我自用的微信骨架 https://github.com/xinshangshangxin/MINA-seed, 注入了 bluebird, lodash, promisify了wx.xxx接口, 修改了 vConsole 不输出function和error

文章若有纰漏请大家补充指正,谢谢~~
http://blog.xinshangshangxin.com SHANG殇