Add e2e tests with ecosystem repositories to prevent regressions

[fengmk2]

Background

Issue #10 revealed that our CI tests were insufficient — they only verified vp --version after installation, which doesn't exercise critical code paths like vp exec and vp run. The Cannot find module 'which' error on Windows went undetected because no test actually ran commands through vite-plus.

Goal

Design and implement an e2e testing workflow that runs real-world ecosystem repositories against the action on all platforms (ubuntu, macos, windows) to catch regressions before they reach users.

Testing Plan

1. Ecosystem Repository Matrix

Include real repositories that use setup-vp in their CI to validate the full workflow:

Repository	Key Commands	Purpose
voidzero-dev/vite-plus	vp install, vp run build, vp run test	Core toolchain — validates install + build + test
cloudflare/vinext (or similar)	vp exec, vp install, vp run	Real consumer — validates exec path that broke in #10

2. Test Scenarios

Each ecosystem repo should be tested with:

• Fresh install (no cache) on all 3 platforms
• Cached install (cache hit) on all 3 platforms
• vp exec — the code path that triggered Windows runner failures with latest action version #10
• vp run — script execution
• vp install — dependency installation
• vp env use — Node.js version switching
• Multiple Node.js versions (e.g., 22, 24)

3. Workflow Design

• Create a separate e2e.yml workflow (to avoid slowing down the main test.yml)
• Trigger on push to main, pull_request, and schedule (e.g., daily) to catch upstream breakage
• Clone ecosystem repos at pinned refs for reproducibility
• Use fail-fast: false so all platform results are visible even if one fails

4. Example Structure

jobs:
  e2e-vite-plus:
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v6
      - uses: ./
        with:
          version: latest
          cache: false
      - uses: actions/checkout@v6
        with:
          repository: voidzero-dev/vite-plus
          path: ecosystem/vite-plus
      - name: Install and build
        working-directory: ecosystem/vite-plus
        run: |
          vp install
          vp run build
      - name: Run tests
        working-directory: ecosystem/vite-plus
        run: vp run test

Acceptance Criteria

• e2e workflow exists and runs on all 3 platforms
• At least 2 ecosystem repositories are included in the matrix
• vp exec, vp run, and vp install are all exercised
• Scheduled runs catch upstream breakage early
• The e2e test would have caught Windows runner failures with latest action version #10 before it reached users

Related

• Windows runner failures with latest action version #10 — Windows runner failures with latest action version
• fix: use staging install scripts to fix Windows runner failures #10 #11 — Temporary fix using staging install scripts