如何在 nodejs 中将 THIS 与 babel 一起使用？

Question

In the past i could use:

var _this = this
...
exports.someFunction = function (req, res) {
    _this.create(someVar)
}
...
exports.create = (someVar) => {
//logic here
return something
}

But since i added BABEL to use GraphQl, package.json :

"devDependencies": {
     "@babel/core": "^7.8.4",
     "@babel/node": "^7.8.4",
     "@babel/preset-env": "^7.8.4",
     "@babel/register": "^7.8.3"
   }

and the .babelrc file with:

{
   "presets": [
     [
       "@babel/env"
     ]
   ]
}

I get the error:

uncaughtException: Cannot read property 'create' of null

Please let me know what I am doing wrong or what I can do in .babelrc to allow the use of this

Thanks.

Answer 1

Because you want to reference a function which is a property of exports , why not reference exports to get to it? No need to depend on the calling context of the module:

exports.someFunction = function (req, res) {
    exports.create(someVar);
}

It sounds like a Babel module's top level is not called with a calling context, so this is undefined (just like it would be in strict mode).