Codecov missing-base minimal repro repository

This repo template reproduces merge-heavy default-branch history with partial flag uploads, so we can validate base-parent behavior and test fixes.

What this template includes

• Minimal Python code and tests with two coverage flag groups:
  • core
  • ext
• codecov.yml configured with carryforward defaults.
• GitHub Actions workflows to:
  • generate many PRs quickly,
  • merge those PRs in a batch,
  • produce main-branch history with intermittent partial uploads.

Workflows

1) CI

Workflow: .github/workflows/ci.yml

• Manual dispatch.
• Select test_suite as core, ext, or both.

2) Create stress PR batches (30-60)

Workflow: .github/workflows/create-stress-batch-prs.yml (manual workflow_dispatch)

Suggested inputs:

• count: 40
• base: main

This generates merge pressure for base-parent stress testing.

3) Merge PRs in batch

Workflow: .github/workflows/merge-batch-prs.yml (manual workflow_dispatch)

This workflow merges all open PRs in the repository.

This simulates batched landings and generates the merge topology to stress base selection.

Local CLI alternative (optional)

Use the merge script if you prefer local control with gh CLI:

bash scripts/merge_batch_prs.sh main 1000

Validation checklist

1. Confirm main has many merge commits:

git log --graph --oneline --decorate --first-parent --max-count=80 main

2. In Codecov, inspect consecutive main commits and check:

• whether base commit is present,
• whether comparisons and carryforward behavior are consistent across stress merges.

Notes

• This template is intentionally minimal to share with Codecov support/engineering.
• count can be inscreased to 30+ to make merge topology more stressful.
• Fast stress profile: run create-stress-batch-prs.yml with count=40, then run merge-batch-prs.yml. Then run ci.yml to upload coverage to Codecov on the head of the main branch.