This seems like a simple thing but I'm a bit of a node/javascript newbie. How can I import a class from another file using node 7.0.0?
I defined my class in one file:
'use strict';
class MyClass {
...
};
module.exports = MyClass;
And I want to use it in another class:
var MyClass = require('./path/to/otherfile');
...
var myclass = new MyClass(some param);
But I'm getting an error from my linter saying
TypeError: Class constructor MyClass cannot be invoked without 'new'
This code is correct and works in Node 7.0.0. See this example:
File class.js:
'use strict';
class MyClass {
}
module.exports = MyClass;
File code.js:
var MyClass = require('./class.js');
var myclass = new MyClass();
console.log('OK');
Run:
node code.js
and you'll see:
OK
What is broken is not your code but your linter but you don't specify what linter are you using so it's hard to say anything more.
I don't know why people suggested that you should use module.exports.MyClass = MyClass; instead of module.exports = MyClass; - it would not only not fix the issue but would actually break the code giving you an error of:
TypeError: MyClass is not a constructor
Also to people suggesting that this should be used:
export default MyClass;
No, it would give an error in Node 7.0.0:
SyntaxError: Unexpected token export
After reading the comments to this question I wonder how many people have actually run the code because as it turns out the code works fine but all the "solutions" in the comments break it.
I made a GitHub project with the original code and suggested solutions tested on Travis with Node versions 4, 5, 6, and 7. You can see it here:
with test results available at:
When I know which linter is causing the problem I'll add it to the project and we'll see what can be done about it.
