Add possibility to put every class in separate file

[PavelTurk]

Suggestion

I suggest to add possibility to put every class in separate file although they belong to one ES6 module and TypeScript must generate one module with these classes.

Use Cases

Because it is a standard and convenient way to develop classes.

Examples

Java, C#?

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript / JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. new expression-level syntax)

[RyanCavanaugh]

You can already accomplish this today by re-exporting the classes.

[PavelTurk]

@RyanCavanaugh Can you give a link to re-exporting the classes feature? I found examples only here https://stackoverflow.com/questions/29168813/typescript-how-to-export-two-classes-in-separate-files-in-one-module but they all suppose extending in final module classes that are in separate files. So it is hard to call a feature, it is likely a workaround.

[PavelTurk]

The question about this was asked on StackOverflow https://stackoverflow.com/questions/52570738/how-to-merge-two-classes-in-separate-files-into-one-es6-module-using-typescript