Describe your environment

• Operating System version: macOS Sierra
• Firebase SDK version: 4.9.0
• Firebase Product: auth, database

Describe the problem

We are using a monorepo and have a module (A) which depends on another module (B). Both of firebase listed as dependency. Compiling module B is not a problem. Compiling module A however is. These errors are showing up:

I tweeted about this, and @DanielRosenwasser replied that it should be fixed in here. https://twitter.com/drosenwasser/status/957872358978609152

I was able to solve it with paths mappings in tsconfig.json, but would be nice if it just worked without.

Steps to reproduce:

1. Create 2 modules which both have firebase as dependency
2. Link one module to the other yarn add link:../module-b
3. Compile

(Better to look at the reproduction repository)

Relevant Code:

Here's the repository I created to reproduce the problem. https://github.com/SamVerschueren/firebase-duplicate-tsd

// @jshcrowthe