docs: add JS test placement rule to AGENTS.md

Adds a "Tests for JavaScript / npm / package.json invariants belong
in the JS suite" subsection under Testing, documenting that the CI
classifier routes package.json / lockfile / .ts/.tsx changes to the
frontend lane — so Python tests asserting about those files won't run
on a JS-only PR. Includes a table mapping artifact types to the
correct vitest workspace and run commands.
This commit is contained in:
ethernet 2026-07-15 12:14:07 -04:00
parent 64389a2ce2
commit f8abc521f3

View file

@ -1278,6 +1278,7 @@ def profile_env(tmp_path, monkeypatch):
## Testing
### Python
**ALWAYS use `scripts/run_tests.sh`** — do not call `pytest` directly. The script enforces
hermetic environment parity with CI (unset credential vars, TZ=UTC, LANG=C.UTF-8,
`-n auto` xdist workers, in-tree subprocess-isolation plugin). Direct `pytest`
@ -1291,12 +1292,12 @@ scripts/run_tests.sh tests/agent/test_foo.py::test_x # one test
scripts/run_tests.sh -v --tb=long # pass-through pytest flags
```
### Subprocess-per-test-file isolation
#### Subprocess-per-test-file isolation
Every test file runs in a freshly-spawned Python subprocess via `run_tests_parallel.py`. This means module-level dicts/sets and
ContextVars from one test file cannot leak into the next.
### Why the wrapper
#### Why the wrapper
| | Without wrapper | With wrapper |
| ------------------- | ------------------------------------------- | ----------------------------------------- |
@ -1305,6 +1306,17 @@ ContextVars from one test file cannot leak into the next.
| Timezone | Local TZ (PDT etc.) | UTC |
| Locale | Whatever is set | C.UTF-8 |
### Where to place what tests
The CI change classifier (`scripts/ci/classify_changes.py`) runs specific jobs based on what files changed. A Python test that asserts
about the contents of `package.json`, `package-lock.json`, `.ts`/`.tsx`
source, or any other JS-side artifact will not run on a PR that only touches
those files. This means a regression can go green on a PR and red on `main` (where the
classifier fails open and runs everything).
Any test that reads or asserts about `package.json`,
`package-lock.json`, `tsconfig.json`, `.ts`/`.tsx`/`.js`/`.mjs`/`.cjs`
source files configuration belongs in the JS (vitest) test suite, not in `tests/*.py`.
### Don't write change-detector tests