Testing Contract

Overview

Use this skill to prevent integration regressions by enforcing provider-consumer contracts in CI.

Scope Boundaries

• Use when interface compatibility between producer and consumer is a release risk.
• Typical requests:
  • Verify an API response change does not break existing consumers.
  • Enforce event schema compatibility in CI.
  • Add provider-consumer contract gates before merge.
• Do not use when:
  • The scope is visual/UI behavior only (testing-e2e or playwright).
  • The scope is isolated unit logic (testing-unit).

Inputs

• Contract definitions and compatibility policy
• Provider/consumer versioning constraints
• Release and rollback requirements

Outputs

• Versioned contract suite and compatibility matrix
• Decision record for contract strategy and migration path
• Verification checklist for provider and consumer pipelines

Workflow

1. Define compatibility policy (backward/forward/strict).
2. Identify contract surfaces and critical consumers.
3. Compare enforcement options and choose one with rationale.
4. Capture provider-consumer compatibility in assets/contract-compatibility-matrix-template.md.
5. Execute provider and consumer verification runs.
6. Publish failures, migration actions, and residual risk.

Quality Gates

• Compatibility policy is explicit and test-enforced.
• Breaking changes include migration and communication plan.
• Contract evidence is reproducible in CI.
• Residual compatibility risk is owned and tracked.

Failure Handling

• Stop when required compatibility policy is violated.
• Escalate when no feasible migration path exists.

Bundled Resources

• references/trigger-and-examples.md: trigger patterns, anti-patterns, and deliverable expectations.
• assets/contract-compatibility-matrix-template.md: compatibility and migration tracking matrix.