run-nx-checks · diff
v1.6 to v1.7
12 added, 19 removed. Audit A to A.
---
name: run-nx-checks
description: Run nx format, lint, test, and build on affected or specified projects, then fix unambiguous failures
context: fork
allowed-tools: Bash, Read, Edit, Write, Grep, Glob
license: MIT
metadata:
- version: "1.6"
+ version: "1.7"
---
# Run Nx Checks
Run format, lint, test, build. Fix unambiguous failures. Report anything judgment-laden.
## Arguments
`$ARGUMENTS` — optional, space-separated: `[cpuCount] [projectName] [--remote-cache]`. Number token
→ `cpuCount`. Non-number, non-flag token → `projectName`. `--remote-cache` flag → opt back into the
remote cache by dropping the remote-cache-off prefix. Default `cpuCount` = cores - 4 (min 1);
count cores with `getconf _NPROCESSORS_ONLN` (`nproc` is GNU-only).
Default project scope = affected. Default remote-cache state = off (see Steps).
## Workspace
Run nx commands from wherever `nx.json` lives in this repo (commonly the root; in some repos a
subdirectory).
## Setup (before step 1)
Keep the Nx daemon warm so the project graph is reused across targets:
```bash
NX_DAEMON=true npx nx daemon --start >/dev/null 2>&1 || true
```
- Do **not** rely on `export` for the remote-cache-off env vars (or any other nx env var) — each Bash
- tool call is a fresh shell, so exports do not carry across calls. Always inline env vars on the
- command line of each nx invocation (see Steps below).
-
## Fix rule
- Apply only mechanical/unambiguous fixes: lint auto-fix output, missing imports/types, obvious type
errors, test expectations that mirror a clear code change.
- Never guess on anything judgment-laden: test failure that could be a real bug vs. an outdated
assertion, errors pointing at unrelated areas, pre-existing failures unrelated to recent work,
anything where multiple plausible fixes exist. Running forked, you can't ask mid-run: leave such
failures unfixed and carry them, with your analysis, into the final report.
- Keep changes minimal and scoped to the failure. No drive-by refactors.
- After fixing, re-run the check. Repeat until clean or only judgment-laden failures remain.
## Affected scope — sanity-check before build/test
Affected runs can balloon. Before steps 3–4, check scope with the graph-only
`npx nx show projects --affected` (fast, no build):
- **Sandbox `.env` false positives.** The sandbox denies reading `**/.env`; `nx affected` hashes
changed files, so an unreadable `.env` reads as *changed* and marks its project affected. Repos
with `.env`-bearing apps (e.g. `apps/*-api`) thus drag those into every affected run and build
them for nothing. Tell-tale: `git status` prints `<path>/.env: Operation not permitted` for
exactly those projects. Fix: rerun the nx commands with the sandbox disabled so `.env` reads
succeed, or `--exclude` those projects.
- **Large fan-out.** If the set is large (e.g. a widely-shared lib change rippling across the
workspace), don't build the world unprompted: skip steps 3–4 and report the project count and
scope in the final report so the user can re-run with an explicit scope.
## Steps
**Scope is mandatory — never narrow it yourself.** With no `$projectName` argument, *every* target
runs at full scope — `nx affected` for lint/test/build, whole-changeset `format:write`. The
single-project forms in the steps below apply **only** when the user explicitly passed
`$projectName`. Never substitute `nx run <proj>:<target>`, `nx <target> <changedLib>`, or
file-scoped `format --files` for the affected sweep: that skips every other affected project —
exactly where a shared-lib change regresses (a dependent project whose tests import the changed
lib). And never add `--skip-nx-cache` (see below).
- Always prefix each nx command with **both** remote-cache-off env vars inline. They're additive and
- the unrecognized one is a no-op, so this is safe regardless of which remote-cache backend (if any)
- the repo uses:
-
- - `NX_POWERPACK_CACHE_MODE=no-cache` — disables Nx Powerpack remote caches (`@nx/azure-cache`,
- `@nx/s3-cache`, `@nx/gcs-cache` — all read the same env var via shared `powerpack-utils`).
- - `NX_NO_CLOUD=true` — disables Nx Cloud's remote read-through cache.
+ Always prefix each nx command with **both** remote-cache-off env vars inline
+ (`NX_POWERPACK_CACHE_MODE=no-cache` for Powerpack remote caches, `NX_NO_CLOUD=true` for Nx Cloud).
+ They're additive and the unrecognized one is a no-op, so this is safe regardless of which
+ remote-cache backend (if any) the repo uses.
The invariant: **remote cache always off (unless the user passed `--remote-cache`), local cache
- always on.** A remote read-through cache gains little locally, and its cloud SDKs' credential
- probing can hang every nx call for seconds in a sandbox; a shell-side auth check (e.g.
- `az account show`) doesn't predict the in-process credential chain — always disable, never
- autodetect. Full rationale: [remote-cache-rationale.md](remote-cache-rationale.md).
+ always on** — always disable, never autodetect (a passing shell-side auth check doesn't predict the
+ in-process credential chain). Why: [remote-cache-rationale.md](remote-cache-rationale.md).
If the user explicitly passed `--remote-cache`, drop both prefixes.
**Always keep the local cache on.** The env vars above disable only the _remote_ read-through cache;
the local Nx cache must stay enabled so unchanged targets are replayed instead of re-run. Do **not**
add `--skip-nx-cache` (nor `NX_SKIP_NX_CACHE=true`) to any command — it bypasses the local cache
too, making every run slower for no benefit. The only valid reason to pass `--skip-nx-cache` is a
specific, stated need to bypass the local cache — e.g. investigating a failure you suspect is caused
by a stale cache entry. In that case, scope it to the single command under investigation and say
why; never use it as the default.
- Write both env vars literally at the start of each nx command, exactly as in the steps below.
- Never stash the prefix in a shell variable (`NX_OFF="…"; $NX_OFF npx nx …` fails with "command not
- found": expanded variables are not parsed as assignments).
+ Write both env vars literally at the start of each nx command, exactly as in the steps below. Do
+ **not** rely on `export` — each Bash tool call is a fresh shell, so exports do not carry across
+ calls (true for any nx env var). Never stash the prefix in a shell variable
+ (`NX_OFF="…"; $NX_OFF npx nx …` fails with "command not found": expanded variables are not parsed
+ as assignments).
1. Lint — `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx affected -t lint --parallel=$cpuCount --fix`
(or `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx lint $projectName --fix`).
2. Format — `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx format:write`
3. Test — `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx affected -t test --parallel=$cpuCount --maxWorkers=1`
(or `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx test $projectName`).
4. Build — `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx affected -t build --parallel=$cpuCount`
(or `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx build $projectName --parallel=$cpuCount`).
Apply the fix rule on any failure in steps 1–4.
### `--maxWorkers=1` on the test step
`--parallel` caps concurrent *projects*; each test task still fans out to ~all cores internally, so
without this the cores oversubscribe (CPU pegs at 100%). `--maxWorkers=1` pins each task to one
worker → `--parallel=$cpuCount` ≈ `$cpuCount` cores. Both Vitest and Jest accept the flag.
- **Test step only.** Forwarding `--maxWorkers` to lint (ESLint) or build (esbuild) fails as an
unknown option.
- **Affected/run-many only, not single-project.** With one project there's no project-level fan-out,
so capping to one worker just serializes it — let a single project use all cores.
Same reason, `--parallel` is dropped from single-project **lint** and **test** (one task each — no
fan-out). It stays on single-project **build**, because `build` has `dependsOn: ["^build"]`, so
building one project fans out across its whole dependency chain.
## Flaky tests — retry once to classify
A failed `test` target may be flaky, not a real break. On a test failure, re-run that one target
once: `NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx test <project>`. If it then
passes, or Nx prints `NX detected a flaky task`, it's flaky — don't try to "fix" it; record it as
a flaky `project:target` for the report. If it fails the same way again, treat it as real under
the Fix rule.
## Final report (mandatory)
This skill runs in a forked context, so its final message is the only channel back to the caller.
End by listing, per target (lint / format / test / build): clean, skipped (with the reason — for
large fan-out, the project count and scope), or each failing `project:target` with its cause, plus
any flaky `project:target`. Never report a bare "checks passed" — an unlisted failure or skipped
target reads as green and the caller can't act on it.