04-lessons-auto-merge.md

Path-based CI: lessons-only PRs skip full test suite

Source: 用户增长-使用者体验改进清单.md item #5; also growth-pains.md pain point #1

Problem

Every PR runs the full CI pipeline (pytest, coverage, quality gate). For lesson-only PRs (changes under lessons/ only), this is wasteful — lessons don't affect Python code. The delay discourages lightweight contributions.

Suggested implementation

In .github/workflows/pr-checks.yml, add a scope detection step at the start:

- name: Detect Change Scope
  run: |
    SCOPE=$(git diff --name-only HEAD~1 | awk -F/ '{print $1}' | sort -u)
    if echo "$SCOPE" | grep -qv "^lessons$"; then
      echo "scope=full" >> "$GITHUB_OUTPUT"
    else
      echo "scope=lessons-only" >> "$GITHUB_OUTPUT"
    fi

• Full scope (any change outside lessons/): run all gates as today
• Lessons-only scope: run only DCO + schema validation, then auto-merge if passing

Acceptance criteria

• Lessons-only PRs skip pytest, coverage, quality score gates
• DCO and schema validation still run on all PRs
• PR with mixed changes (lessons + code) triggers full pipeline
• Auto-merge works for passing lessons-only PRs