Boundary Value Generator

boundary-value-generator

Purpose

Design tests around lower, upper, just-inside, and just-outside boundaries for numeric, ordered, sized, and count-based inputs.

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 or constraints
• ranges or thresholds
• partition model if available

Deliverables

• boundary cases
• off-by-one checks
• invalid edge tests
• boundary rationale

Operating procedure

1. Identify ranges, thresholds, counts, lengths, dates, or ordered values.
2. Generate cases at min, min+1, typical, max-1, max, and just-outside where relevant.
3. Include invalid and off-by-one probes, not just valid boundaries.
4. State why the chosen boundaries matter operationally.

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
• negative-test-designer
• test-oracle-writer

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 only test the boundary itself.
• Do not miss just-outside invalid cases.
• Do not assume all boundaries are numeric.

Minimum output skeleton

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