Collapse pnpm test scripts into a single helper invocation

[lukesandberg]

What?

Every pnpm test-* / pnpm testonly-* script in the root package.json is now a single direct invocation of a new scripts/run-jest.sh helper instead of chaining through several pnpm run + cross-env layers.

Why?

Each hop through pnpm run / cross-env spins up its own Node process and takes a few hundred milliseconds before anything useful happens. For example, pnpm test-dev-turbo used to walk through five layers:

test-dev-turbo
  -> pnpm run with-turbo pnpm test-dev-inner           (cross-env IS_TURBOPACK_TEST=1)
       -> pnpm test-dev-inner                          (cross-env NEXT_TEST_MODE=dev)
            -> pnpm testheadless                       (cross-env HEADLESS=true)
                 -> pnpm testonly
                      -> jest --runInBand

Measured overhead (same machine, same stubbed jest invocation — jest --version)

Chain	Layers	Median (ms)	Range (ms)
jest --version (baseline, direct)	1	80	75–89
pnpm test-dev-turbo --version (new)	pnpm → bash → jest	448	435–493
pnpm test-dev-turbo --version (old)	pnpm → cross-env → pnpm → cross-env → pnpm → cross-env → pnpm → jest	2494	2462–2512

That's ~2 seconds per test invocation shaved off, and ~85% reduction in wrapper overhead (from ~2414 ms to ~368 ms). The remaining ~368 ms is essentially just one pnpm run startup, which is unavoidable while we keep the pnpm test-* entry points.

Real-world impact: for a ~72 s e2e test run this is ~3%, but for fast unit-test files (often <5 s) this is closer to 30-40%, and it adds up quickly in CI jobs that shell out to these scripts in a loop.

How?

• New scripts/run-jest.sh parses named flags and execs jest directly:
  • --mode=<dev|start|deploy> → sets NEXT_TEST_MODE
  • --bundler=<webpack|turbo|rspack> → sets IS_WEBPACK_TEST=1 / IS_TURBOPACK_TEST=1 / NEXT_RSPACK=1 NEXT_TEST_USE_RSPACK=1
  • --experimental → sets __NEXT_CACHE_COMPONENTS=true __NEXT_EXPERIMENTAL_APP_NEW_SCROLL_HANDLER=true
  • --headless → sets HEADLESS=true
  • -- terminates flag parsing; everything after is forwarded verbatim to jest so existing workflows like pnpm test-dev-turbo path/to/foo.test.ts -t "pattern" keep working.
• Every test-* / testonly-* entry in package.json (including testheadless) now reads like scripts/run-jest.sh --mode=dev --bundler=turbo --headless --. No more pnpm run / cross-env indirection at the top level.
• Removed nine unused internal intermediates (test-dev-inner, test-dev-experimental-inner, test-start-inner, test-start-experimental-inner, test-deploy-inner, testonly-dev-inner, testonly-start-inner, testonly-deploy-inner, test-inner). These were only called by other package.json scripts and not referenced anywhere else in the repo.
• Kept testonly, testheadless, and all public test-* / testonly-* names so AGENTS.md, contributing/core/testing.md, .conductor/, and .agents/skills/ work unchanged.
• The with-webpack, with-turbo, with-rspack, and with-experimental prefix scripts remain for ad-hoc use; they are just no longer in the hot path of the test scripts.
• scripts/run-jest.sh invokes a bare jest, which resolves via $PATH (pnpm prepends node_modules/.bin/ when running a package script). The helper is documented as only supported when invoked through a package runner.

Verification

Ran a small e2e test through the new chain in both dev+turbopack and start+webpack modes. Output confirms env vars propagate correctly (PASS Turbopack ... / PASS webpack ..., plus pnpm next --turbopack vs pnpm next start in the logs):

pnpm test-dev-turbo test/e2e/app-dir/_allow-underscored-root-directory/...
  -> PASS Turbopack ... 3 passed

pnpm test-start-webpack test/e2e/app-dir/_allow-underscored-root-directory/...
  -> PASS webpack ... 3 passed

CI is unaffected: every workflow invokes node run-tests.js ... directly, never through these pnpm scripts.

[lukesandberg]

Merge activity

• Apr 21, 11:53 PM UTC: @lukesandberg merged this pull request with Graphite.