Lumitrace

See what your Ruby code actually did — per pull request.

Lumitrace instruments the lines a PR touches, records the expression values while your tests run, and posts a GitHub Check with a coverage summary and a link to a full HTML report overlaying those values on your code.

Add it to a workflow

Take your existing test workflow and add the highlighted lines — your test command stays exactly the same:

name: test
on: pull_request

permissions:
  checks: write
  contents: read
  id-token: write                          # upload the report (omit = PR check only)

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: ruby/setup-ruby@v1
        with: { bundler-cache: true }
      - uses: ko1/lumitrace/action/setup@v1
      - run: bundle exec rake test           # unchanged
      - uses: ko1/lumitrace/action/report@v1
        if: always()

How reports are shared

• Public repos — reports are world-readable.
• Private repos — require a GitHub login with access to the repo (install the Lumitrace Reports app); private source and values never leak.
• Reports are kept for 7 days.

→ See an example report