Support typeorm@0.3.0 plain object repositories

[matomesc]

I'm submitting a...

[ ] Regression 
[ ] Bug report
[x] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

With typeorm@0.3.0 release around the corner, repositories are no longer classes but plain objects, so instanceof checks will fail and the following won't work in 0.3.0:

https://github.com/nestjs/typeorm/blob/master/lib/common/typeorm.utils.ts#L32
https://github.com/nestjs/typeorm/blob/master/lib/typeorm.providers.ts#L17

Expected behavior

Don't use instanceof checks and use the typeof property to check the type of a repository and generate injection tokens:
https://github.com/typeorm/typeorm/blob/b177e230a6fcb11f1eb71d4d431d0297436b7f6f/src/repository/Repository.ts#L29

Minimal reproduction of the problem with instructions

What is the motivation / use case for changing the behavior?

Environment

Nest version: 7.x.x

[kamilmysliwiec]

Out of curiosity, do you know what was the motivation behind this change? Do you have a link to the PR by any chance? :)

[kamilmysliwiec]

PS. Would you like to create a PR for this issue? We could detect support both 0.2.x and 0.3.x by adding an additional check (else if)

[matomesc]

This is the commit that introduced the repository refactor: typeorm/typeorm@ba4bebe

Then the instanceof property was added to repository in this commit typeorm/typeorm@d7e710f but renamed to typeof in this commit typeorm/typeorm@349b067.

I'll open a PR shortly.

[stewartmcgown]

I have my fork (https://github.com/stewartmcgown/typeorm) set up with the latest TypeORM RC including literal EntityManager injection. Custom Repositories don't work, but we're using it in production just fine for everything else.

[kamilmysliwiec]

Let's track this here #384