This is a bit of a weird one. I've noticed that there are certain scenarios where esmock fails with NPM's Workspaces.
I'm not entirely sure where to start with this particular issue, though. But I went ahead and created an example repo that reproduces the issue.
If you clone the repo, you can reproduce the issue by running the following:
npm run setup
npm run test
If you're not on a UNIX-based system, you can run the commands manually:
git submodule init
git submodule update
cd esmock
git apply ../add-tests.patch
cd ..
npm install
npm run --workspace=esmock test
Notice the following failure:
# Subtest: should mock a node_module
not ok 17 - should mock a node_module
---
duration_ms: 0.028361695
failureType: 'testCodeFailure'
error: |-
Expected values to be strictly equal:
+ actual - expected
+ 'not_mocked'
- 'foobar'
code: 'ERR_ASSERTION'
stack: |-
TestContext.<anonymous> (file:///home/jdalrymple/src/by-project/esmock-ws/esmock/spec/node/esmock.node.test.js:226:10)
async Test.run (node:internal/test_runner/test:338:9)
async Test.processPendingSubtests (node:internal/test_runner/test:158:7)
...