Input Domain Partitioner

input-domain-partitioner

Purpose

Create a clean domain model of input classes, relationships, and constraints before selecting detailed tests.

Trigger this skill when

• You need disciplined test design rather than ad hoc case generation.
• You need to justify why a test set is sufficient.
• You want a reusable artifact that can feed automation later.

Expected inputs

• requirements
• field definitions
• range and format rules
• cross-field constraints

Deliverables

• input domain model
• equivalence class candidates
• cross-field restrictions
• selection guidance

Operating procedure

1. Catalog every input, field, and cross-field dependency.
2. Group values into meaningful classes before choosing exact cases.
3. Record restrictions such as formats, uniqueness, cardinality, and cross-field rules.
4. Produce a partition map that downstream test design can reuse.

Quality gates

• Be explicit about infeasible, unreachable, or assumption-heavy cases.
• Prefer lean, justified test sets over exhaustive-looking noise.
• Keep expected outcomes observable and tied back to rules or logic.
• Show why each test exists, not just the test data.

Handoff targets

• equivalence-partitioning-generator
• pairwise-test-generator
• negative-test-designer

Output style

• Be explicit about uncertainty, infeasibility, and residual risk.
• Prefer compact, explainable artifacts over bloated lists.
• Tie tests back to rules, logic, or structure.
• Make expected outcomes observable.

Failure modes to avoid

• Do not jump straight to test values before modeling the domain.
• Do not miss cross-field constraints.
• Do not mix unrelated dimensions into one class.

Minimum output skeleton

## Summary
## Findings
## Structured outputs
## Coverage / rationale
## Assumptions
## Open questions
## Recommended next skill