Test Engineering

Test Engineering

Repository continuity composition

For repository-scoped work, compose maintain-repository-continuity in Resume mode before selecting work. After an authorized repository change passes domain validation, compose Refresh and Verify immediately before presenting the pull request, and include the reconciled root CONTINUITY.md in the same change. A policy-permitted no-change or exemption result must be documented instead of fabricating an edit.

• Contribute: Behavior under test, deterministic coverage, exact commands and outcomes, remaining gaps, and residual risk
• Never claim: That tests prove behavior, environments, or integrations they did not exercise

Purpose

Increase confidence with deterministic tests that cover meaningful behavior, risk, and boundaries without weakening assertions or overfitting to implementation trivia.

Required Inputs

Resolve as much of the following as possible:

• behavior or contract at risk
• failure impact and the boundary under test
• existing coverage and why it is insufficient
• repository test conventions, infrastructure, and validation commands
• sources of nondeterminism such as time, randomness, network, or environment

Workflow

1. model the risk and choose the lowest sufficient test layer

2. design deterministic fixtures, seams, and assertions using:

   • ./references/determinism-checklist.md
   • ./templates/TEST_PLAN.template.md

3. assert observable behavior and meaningful state transitions

4. add success, failure, boundary, and recovery coverage proportional to risk

5. write a regression test when addressing a defect

6. validate with the smallest focused command first, then broader required checks

7. report covered behavior, remaining risk, and any required follow-up testability work

Constraints

• Do not chase coverage percentages by weakening assertions.
• Do not paper over flakiness with sleeps, retries, or disabled tests.
• Do not test implementation trivia when observable behavior suffices.
• Do not duplicate the same assertion across many layers without added value.
• Do not update expected output blindly after a failing test.

Completion Criteria

• The chosen test layer is justified by risk and cost.
• Tests are deterministic and assert meaningful behavior.
• Important success, failure, or boundary paths are covered proportionally.
• Validation commands and outcomes are explicit.
• Remaining risk and follow-up seams are visible.

Provenance

This canonical skill is first-party Ego Hygiene content curated from the staged candidate at .staging/skills/test-engineering/SKILL.md.

Source Delta

• Adopted: the staged focus on risk modeling, layer selection, deterministic design, and anti-flakiness constraints.
• Rewritten: canonical metadata, deterministic-testing resources, and explicit update/regression eval coverage.
• Rejected: the narrower breakdown-test and pytest-coverage overlaps as canonical identities because the core workflow must stay general-purpose and behavior-focused rather than framework- or coverage-metric-centric.