testing-strategy

name	testing-strategy
description	Shapes risk-based test strategy for code changes. Use when deciding what to test, balancing test layers, improving fixture quality, targeting regressions, or controlling flakiness. Triggers — "test plan", "which tests to write", "coverage gap", "flaky", "regression". Negative trigger — routine single-unit-test additions with no strategy questions.
license	MIT
allowed-tools	["Read","Grep","Glob","Bash(*)","Write"]
metadata	{"author":"garda-agent-orchestrator","version":"1.0.0","domain":"quality","triggers":"test plan, test strategy, coverage gap, regression, flaky test, fixture, test data, contract test, integration test balance","role":"specialist","scope":"review-and-advisory","output-format":"findings-and-checklist","related-skills":"orchestration, code-review, architecture-review"}

Testing Strategy

Core Workflow

1. Identify the risk surface. List changed modules and their outbound contracts (APIs, events, persistence, UI entry points). Rank each by blast radius — a shared service adapter outranks a leaf utility.
2. Map existing coverage. Locate test files that exercise the changed paths. Note missing layers: if only unit tests exist for a module with external integrations, flag the gap.
3. Select the right test layer per risk.
   • Contract / API tests — for any change to a public interface, schema, or serialized format.
   • Integration tests — for persistence, external calls, queue interactions, or multi-module flows.
   • Unit tests — for pure logic, transformations, and edge-case branches.
   • E2E / smoke tests — only when user-facing workflows or critical paths are affected.
4. Evaluate fixtures and test data. Verify that existing fixtures reflect production-realistic shapes. Flag hardcoded IDs, missing nullable fields, or stale schema snapshots.
5. Check for flakiness vectors. Review time-dependent assertions, uncontrolled network calls, shared mutable state, test ordering dependencies, and non-deterministic data.
6. Recommend a minimal effective test set. Prioritize high-risk paths over exhaustive low-value coverage. State explicitly which paths do not need new tests and why.

Reference Guide

Topic	Reference	Load When
Strategy checklist	references/checklist.md	Any test-strategy decision or review

Mandatory Output Format

When this skill is selected for a mandatory test review, return the generated output template, not a free-form summary. Preserve these headings exactly and in this order:

1. ## Validation Notes - concrete reviewed test files, behavior, boundaries, and verification evidence; required for PASS.
2. ## Findings by Severity - active blocking test findings with file references, or none.
3. ## Deferred Findings - accepted actionable test follow-ups with a concrete next step and Justification:, or none.
4. ## Residual Risks - active open testing risks that remain after review, or none.
5. ## Verdict - exact verdict token: TEST REVIEW PASSED or TEST REVIEW FAILED.

Anti-Patterns

• Coverage target as strategy: treating line coverage percentage as the goal instead of asking which failures actually matter.
• Redundant layer overlap: asserting the same field or branch in unit, integration, and end-to-end tests without increasing defect-detection value.
• Mock-only confidence: using pure unit tests to "prove" correctness for integration-heavy code that actually fails at boundaries.
• Permanent flaky quarantine: moving unstable tests out of the main path without a plan to fix or replace the lost signal.

Constraints

• Do not demand 100 % line coverage; optimize for defect-detection value per test.
• Do not duplicate assertions across layers — if a contract test covers a field, the unit test should not re-check serialization.
• Do not treat mocks as proof of correctness; prefer narrow real integrations when setup cost is low.
• Do not ignore flakiness; a flaky test that is skipped is worse than no test because it erodes signal trust.
• Avoid snapshot tests for volatile output; prefer structural assertions.
• Never recommend tests that depend on execution order or shared external state without explicit isolation.