ENGINEERING

Uncovered-diff test-stub authoring agent

When an MR is labeled coverage-regression, an agent reads the uncovered diff lines, drafts matching test stubs.

CategoryEngineering
EngineSim + Paperclip
Difficultyadvanced
Triggerevent
Steps6
Setup~25 min

How it runs

The automated pipeline, trigger to output.

  • Triggercoverage-regression label addedGitLabGitLab
  • ActionFetch MR diff + uncovered linesGitLabGitLab
  • ActionAgent drafts targeted test stubsOpenAI
  • LogicValidate stubs map to real symbols
  • ActionPost stubs as MR suggestionGitLabGitLab
  • OutputNotify author in SlackSlack

What it does

When a merge request carries the `coverage-regression` label, this agent-driven workflow pulls the specific uncovered added lines, reasons about what behavior they introduce, and drafts test stubs that target those paths. It posts the proposed tests back on the MR as a suggestion the author can apply with one click.

When to use it

Use it when coverage gates keep catching MRs but authors stall on writing the tests. The agent turns a regression flag into a concrete starting point, lowering the effort to close the gap. Best for teams comfortable reviewing AI-drafted tests before merging.

How it works

  1. 1A GitLab label-added webhook fires for the `coverage-regression` label.
  2. 2The flow fetches the MR diff and the uncovered-line set from the pipeline coverage artifact.
  3. 3An agent reads the uncovered code plus nearby context and drafts targeted test stubs.
  4. 4A logic step verifies the drafts reference real symbols and skips files it cannot map.
  5. 5It posts the stubs as a suggested-changes comment and notifies the author in Slack.

Set it up

What you configure once, before turning it on.

  1. 1
    Connect GitLabRepos, MRs, pipelines, registry.
  2. 2
    Connect OpenAIModels, embeddings, files.
  3. 3
    Connect SlackChannels, DMs, threads, mentions.
  4. 4
    Set each agent's modelWe leave models unset so you pick the tier — fast + cheap, or top-quality.
  5. 5
    Tune it to your dataEdit the prompts, filters, and field mappings so it matches how your team works.
  6. 6
    Test, then turn it onRun once against a sample, confirm the output, then enable the trigger.

Run this workflow in your colony.

14-day trial. No DevOps. No Sales call. Provisioned in under a minute.