replaceEsm breaks usage of mongo db

[paymog]

Description

Using replaceEsm breaks usage of Mongo in the files under test

Issue

See repo for details. I have a module, A with a dependency on another module, B. Module A queries Mongo DB. When testing module A, I call replaceEsm('path/to/B') and this causes all queries to Mongo in module A to return nothing. However, I also have another module C which also queries Mongo. If I make calls to module C from the tests of module A, the mongo queries work as expected.

It seems there might be an issue with replaceEsm + imports in beforeEach + mongo db.

Environment

• node -v output: v17.6.0
• npm -v (or yarn --version) output: 8.5.1
• npm ls testdouble (or yarn list testdouble) version:
  example@ /Users/paymahn/code/tripvector/example
  └── testdouble@3.16.5

Example Repo

Here's a minimal repo: https://github.com/paymog/testdouble-example

[giltayar]

Unfortunately, when running the sample repo it has a problem connecting to mongo, which makes sense given that I don't have mongo isntalled. If you can give me instructions on how to run this test with a mongo on docker, I'd love to help.

[giltayar]

Note that looking at the code, you're td.replaceEsm-ing the validations.js after you've imported the module, so even if mongo works, your mocking of that module won't really happen.