fix: CI failing on @rollup/rollup-linux-x64-gnu missing optional dep

[Copilot]

npm ci silently skips platform-specific optional dependencies when the lock file was generated on a different OS (npm/cli#4828), causing Vitest/Rollup to throw Cannot find module @rollup/rollup-linux-x64-gnu at startup. Failing run: #25089724982.

Root Cause

package-lock.json was committed from macOS and only recorded @rollup/rollup-darwin-arm64. Since npm ci strictly follows the lock file, @rollup/rollup-linux-x64-gnu was never installed on the Linux CI runner — even a node_modules wipe-and-reinstall fallback failed because it also ran npm ci against the same stale lock file.

Changes

• Regenerate package-lock.json — primary fix. Deleted the stale macOS-generated lock file and regenerated it from scratch on Linux (npm cache clean --force + npm install). The new lock file records all platform-specific rollup binaries (linux, darwin, win32, etc.) as optional: true, so npm ci on any platform installs the correct native binary.

• Remove cache: npm from actions/setup-node in both ci.yml and deploy.yml — belt-and-suspenders fix. Prevents a warm npm cache from poisoning optional-dep resolution.

• Add defensive post-install guard in both workflows — probes the native binary after npm ci; if still absent, wipes node_modules and reinstalls from scratch before tests run. Emits a workflow warning so the fallback is visible in logs.

- name: Verify Rollup native module (clean reinstall if missing)
  run: |
    node -e "require('@rollup/rollup-linux-x64-gnu')" 2>/dev/null || \
      (echo "::warning::@rollup/rollup-linux-x64-gnu missing – performing clean reinstall" && \
       rm -rf node_modules && npm ci)

Original prompt

Create a pull request in DynamoDS/DynoDashGame to fix the GitHub Actions workflow failing in CI.

Context:

• Workflow: .github/workflows/deploy.yml
• Failing run: https://github.com/DynamoDS/DynoDashGame/actions/runs/25089724982
• Failure message (from job logs): Error: Cannot find module @rollup/rollup-linux-x64-gnu during npm test (Vitest startup / Rollup native module).
• The workflow currently uses actions/setup-node@v4 with node-version: 20 and cache: npm, then runs npm ci, npm test, npm run build, and uploads dist.

Goal:

• Update the workflow YAML to avoid this intermittent missing Rollup optional dependency issue.

Requirements:

1. Implement a reliable fix:
   • Prefer removing or adjusting actions/setup-node npm caching if it is the likely root cause.
   • Alternatively/additionally add a small defensive step after install to verify that @rollup/rollup-linux-x64-gnu can be required; if missing, perform a clean reinstall (e.g., remove node_modules and rerun npm ci, avoiding deleting package-lock.json unless necessary).
2. Keep the workflow behavior the same: tests then build then upload Pages artifact from dist.
3. Keep changes minimal and well-commented so future maintainers understand why.
4. Ensure the YAML remains valid and uses pinned major versions for actions.

Deliverables:

• A PR that updates .github/workflows/deploy.yml accordingly.
• PR title should mention fixing CI Rollup optional dependency install failure.
• PR description should:
  • Link to the failing run
  • Explain why the failure occurs
  • Explain the chosen mitigation and tradeoffs (cache vs reliability)

The following is the prior conversation context from the user's chat exploration (may be truncated):

User: Why did this job fail?

Assistant: The job failed during the test step when vitest run tried to start up, because Rollup’s Linux native binary package wasn’t present in node_modules.

From the job log (run 25089724982, job 73513077056):

• > vitest run
• Startup Error: Error: Cannot find module @rollup/rollup-linux-x64-gnu
• The stack points at: node_modules/rollup/dist/native.js
• Then the step exits with code 1.

This is a known npm/optional-dependencies issue (the log even references https://github.com/npm/cli/issues/4828): the platform-specific optional dependency for Rollup sometimes doesn’t get installed correctly in CI, so Vitest/Vite/Rollup can’t load the native module and aborts.

Link to the failing job log (same ref as the run):
https://github.com/DynamoDS/DynoDashGame/actions/runs/25089724982/job/73513077056#step:5:42

If you want, paste your .github/workflows/deploy.yml install steps (npm ci vs npm i, caching, Node version), and I can suggest the most reliable fix for this workflow.

User: ```
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4

  - uses: actions/setup-node@v4
    with:
      node-version: 20
      cache: npm

  - name: Install dependencies
    run: npm ci

  - name: Run tests
    run: npm test

  - name: Build
    run: npm run build

  - uses: actions/upload-pages-artifact@v3
    with:
      path: dist

Assistant: That failure is consistent with an **npm optional-dependency install/cache problem** in Actions:

- `rollup` loads a platform-specific optional package at runtime (on `ubuntu-latest` that’s `@rollup/rollup-linux-x64-gnu`).
- With `actions/setup-node cache: npm`, the cached `~/.npm` content can sometimes produce an install where that optional dependency is **missing**, even though `npm ci` succeeds.
- Then `npm test` → `vitest` → `rollup/dist/native.js` throws: *Cannot find module @rollup/rollup-linux-x64-gnu*.

### Most reliable fix (recommended): don’t use the built-in npm cache here
Remove `cache: npm` from `setup-node` (or switch to a different caching strategy). This avoids restoring a “bad” npm cache state that leads to missing optional deps.

```yaml
- uses: actions/setup-node@v4
  with:
    node-version: 20
    # cache: npm   # remove this

If you want to keep caching anyway

Add a defensive reinstall specifically when the Rollup native module is missing (keeps the workflow resilient):

- name: Install dependencies
  run: npm ci

- name: Ensure rollup native deps present
  run: node -e "require('@rollup/rollup-linux-x64-gnu')" || (rm -rf node_modules package-lock.json && npm i)

(You could also replace npm i with npm ci after regenerating the lock, but typically you don’t want to delete the lock in CI unless you accept lockfile changes.)

Also check: are you on npm 10.x?

Node 20 on GitHub-hosted runners typically uses npm 10+, and this class of issue tends to show up there. If you want an additional mitigation, you can pin npm to a known-good version in the workflow:

- run: npm i -g npm@9

Quick recommendation

Start with the simplest: remove cache: npm, re-run the...

This pull request was created from Copilot chat.

[QilongTang]

@copilot The PR check is failing, fix it as part of this same PR

[Copilot]

@copilot The PR check is failing, fix it as part of this same PR

The CI failure was in a separate ci.yml workflow (the PR check) which also had cache: npm and the same Rollup optional-dep issue. Applied the identical fix there in commit 7ba5193: removed cache: npm from actions/setup-node and added the defensive reinstall guard.

[QilongTang]

@copilot The CI check is still failing, try again

[Copilot]

@copilot The CI check is still failing, try again

Found the real root cause: package-lock.json was committed from macOS and only contained @rollup/rollup-darwin-arm64. Since npm ci strictly follows the lock file, it never installed @rollup/rollup-linux-x64-gnu on CI — even the fallback reinstall failed because it also ran npm ci against the same stale lock file.

Fixed in commit b24b700: regenerated package-lock.json from scratch on Linux (with npm cache clean --force + fresh npm install). The new lock file records all platform-specific rollup binaries (linux, darwin, win32, etc.) as optional: true, so npm ci on any platform now installs the correct native binary. Verified locally with rm -rf node_modules && npm ci && npm test — all 109 tests pass.