js intellisense issues about the custom export module.

[mjbvz]

From @tsanie on June 12, 2017 12:40

Issues:

The intellisense doesn't work when I import a constructor, but after I change the module.exports to an object, it seems right.

Steps to Reproduce:

1. Create a file named 'mod.js', write these lines.

function Test(name) {
  this.name = name;
}
Test.prototype.log = function (msg) {};
module.exports = Test;

2. Create another file named 'test.js'.

const Test = require('./mod');
let a = new Test('test');
a.    // <- here, the intellisense cannot list the 'name' and 'log'

3. Then change the files.

'mod.js'

-module.exports = Test;
+module.exports = { Test };

'test.js'

-let a = new Test('test');
+let a = new Test.Test('test');
a.    // now the intellisense seems good.

Screen record

Copied from original issue: microsoft/vscode#28517

[mjbvz]

Tested with current TS 2.4-insiders. I believe the issue is that the type of module.exports in

function Test(name) {
  this.name = name;
}
Test.prototype.log = function (msg) {}

module.exports = Test;

is a function with signature (name: any) => void instead of being identified as a class

[rbuckton]

Fixed, pending PR.