fix-flaky-pr-pdq

name	fix-flaky-pr-pdq
description	Fix a flaky test and complete the connected delivery workflow in PDQ repos: reproduce/fix, verify with repeat-until-failure, open a draft PR with low-risk labeling, wait for Elixir CI to pass, create a Linear Platform ticket labeled engineering task, update the PR title with the ticket key (for example [PLT-123]), and rerun ticket requirement checks.

Fix Flaky Pr Pdq

Overview

Use this workflow when the user asks for end-to-end flaky-test remediation plus PR, CI, and ticket automation. Keep changes minimal, verify the flaky test with stress reruns, and finish with an auditable PR linked to a Linear ticket.

Guardrails

• Work only on the requested flaky test and directly related code.
• Do not revert unrelated dirty workspace changes.
• Prefer deterministic test adjustments over production-code changes unless root cause is in production logic.
• Preserve the original intent of the test. If the only stable fix changes intent/coverage, stop and report that to the user instead of forcing a rewrite.
• Use conventional commits.
• Keep the PR in draft state until requested otherwise.

Workflow

1. Identify the flaky test and nearby implementation.

   • Reproduce with a focused command first (single test or file).
   • Run dependency setup early: mix deps.get and pnpm install.

2. Apply the minimal fix.

   • Stabilize timing/race-sensitive tests with tighter control of batch sizes, delays, or assertions.
   • Prefer narrowing test setup to a single record when validating a specific race path.

3. Verify locally.

   • Run the specific test.
   • Run repeat-until-failure once for the target test (use the repo's expected iteration count, often 100).
   • Capture pass/fail outcome and seeds when available.

4. Commit and open draft PR.

   • Before commit/push, ensure dependencies are installed: mix deps.get and pnpm install.
   • Stage only relevant files.
   • Create a conventional commit message focused on why the test is now stable.
   • If a PR template exists under .github/, use it when composing the PR body.
   • Push branch and open a draft PR with clear summary and verification.
   • Prefer creating the PR with label at creation time (--label "low risk") instead of a follow-up edit.

5. Wait for CI completion.

   • Poll PR checks with gh until Elixir tests complete.
   • Ignore non-blocking checks for this workflow such as Playwright suites and preview build/deploy (Build and Push, web preview).
   • Continue only when Elixir tests are successful.

6. Prepare Linear MCP access, then create Linear ticket.

   • Ensure MCP servers are synced first: task ai:mcps:sync:default.
   • Confirm Linear MCP is connected before ticket operations.
   • Team: Platform.
   • Add label: engineering task.
   • Save returned issue key (for example PLT-123).

7. Update the ticket with implementation status.

   • Add the draft PR URL.
   • Add commit SHA.
   • Include the core flaky failure signal (expected {:error, _}, got :ok) and test location.
   • Note the next action: rerun ticketing check after PR title is updated with issue key.

8. Update PR title and rerun ticket requirement check.

   • Update PR title to include the issue key suffix, for example: fix: stabilize rbac downgrade flaky test [PLT-123].
   • Wait briefly for Linear automation to post the ticket comment on the PR.
   • Rerun the CI check named Test / Ensure work is ticketed.
   • Confirm the check passes.

Command Patterns

• Dependency bootstrap:
  • mix deps.get
  • pnpm install
• MCP bootstrap:
  • task ai:mcps:sync:default
  • opencode mcp list
• Focused flaky verification:
  • mix test path/to/test_file.exs:LINE
  • mix test path/to/test_file.exs:LINE --repeat-until-failure 100
• PR lifecycle:
  • gh pr create --draft --label "low risk" --title "..." --body-file .github/pull_request_template.md (or another repo template path, when present)
  • gh pr edit <pr-number> --add-label "low risk"
  • gh pr checks <pr-number> --watch
  • gh run rerun <run-id> (for rerunning Test / Ensure work is ticketed once ticket metadata is present)
• Linear lifecycle (CLI naming may vary by environment):
  • Create issue via Linear MCP with Platform team + engineering task label.
  • Update created issue with PR URL, commit SHA, and failure context.
  • Capture the created key and inject it into the PR title.

Completion Criteria

• Target flaky test is stable in repeat-until-failure run.
• Draft PR exists and has low-risk label.
• Elixir CI is green.
• Linear Platform issue with engineering task label exists.
• PR title contains the Linear key.
• Ticket requirement CI check has been rerun and passed.

Example Failure Input

Use the exact user-provided failure to anchor reproduction:

1) test run_rbac_downgrade/1 returns an error if none of the permissions are updated (Houston.RolesTest)
   lib/houston/roles_test.exs:487
   match (=) failed
   code:  assert {:error, _} = Task.await(task)
   left:  {:error, _}
   right: :ok
   stacktrace:
     lib/houston/roles_test.exs:514: (test)