No intellisense when exporting es3 style class

[dbaeumer]

From Denys Yefimenko (@denysyefimenko) on April 18, 2016 11:9

• VSCode Version: 1.0.0
• OS Version: Windows 10 Enterprise

Steps to Reproduce:

1. Create two js files.

moduleA.js

var constructorFunction = function () {};
constructorFunction.prototype.prototypeMethod = function () {};
module.exports = constructorFunction;

moduleB.js

var moduleA = require('./moduleA');
var constructedObject = new moduleA();
constructedObject.

1. Try get intellisense suggestion after dot in moduleB.
2. No intellisense provided.
3. If I change code in moduleA as following:

function constructorFunction () {}
constructorFunction.prototype.prototypeMethod = function () {};
module.exports = constructorFunction;

intellisense in moduleB starts working.

Expected result: intellisense works no matter how exported function is defined.

Copied from original issue: microsoft/vscode#5442

[dbaeumer]

Denys Yefimenko (@denysyefimenko) the change part reads exactly the same as in steps. e.g

function constructorFunction () {} 
 constructorFunction.prototype.prototypeMethod = function () {}; 
 module.exports = constructorFunction; 

Are we missing something ?

[dbaeumer]

From Denys Yefimenko (@denysyefimenko) on April 18, 2016 11:58

Yes, you do :) In changed part I declared constructorFunction without using var variable = function() {...} construction.

[dbaeumer]

Thanks. Missed that.

Moving to TS.

[billti]

Interesting... ping Ryan Cavanaugh (@RyanCavanaugh) . Do we infer JS types from function declarations differently to function expressions?

[sandersn]

Looks related (or identical) to #7586, where the language service treats TypeScript and JavaScript function expressions worse than function declarations. I think that fixing #7586 will fix this, but this example should be added as a test.

[sandersn]

Actually, the fix for #7586 (#9010) doesn't fix this. Looks like it will need a separate fix.