error-guessinglisted

Apply this skill whenever you need to design supplementary test cases using Error Guessing — an experience-based test design technique. Use after applying black-box techniques (Domain Testing, Decision Table, State Transition, Use Case Testing) to identify additional high-value test cases targeting defect-prone areas that systematic techniques may miss. Triggers include: "error guessing", "what else should we test", "edge cases", "what could go wrong", "attack the system", "fault attack", "experience-based testing", or any request to supplement an existing test suite with additional risk-based cases. Also use when the tester has domain knowledge, historical defect data, or heuristic intuition about where defects are likely to hide.
phatnguyen975/functional-test-design · ★ 0 · Web & Frontend · score 70

Install: claude install-skill phatnguyen975/functional-test-design

# Error Guessing Skill ## Overview **Error Guessing** is an **experience-based test design technique** defined in ISTQB Foundation Level Syllabus where testers use their knowledge, intuition, and experience to anticipate where defects are likely to occur — then design test cases specifically targeting those areas. Unlike black-box techniques (EP, BVA, Decision Table, State Transition), Error Guessing has **no formal derivation procedure**. Its effectiveness depends on the tester's ability to reason about: - Common programming mistakes and error-prone constructs. - Historical defect patterns in the system or similar systems. - Boundary and special-value behavior beyond formal BVA. - Interactions between components, configurations, and data states that create unexpected behavior. **Core purpose:** Supplement systematic techniques by targeting the gaps they leave — the "middle of the valid class" defects, integration edge cases, data combinations, and implementation-specific failure modes that rules-based techniques cannot reliably surface. **ISTQB classification:** Experience-Based Test Design Technique. Also known in practice as **Fault Attack** — a structured variant where guesses are organized into lists or taxonomies rather than applied ad hoc. → For full theoretical background, see [`resources/theory.md`](resources/theory.md). ## Invoke Syntax ``` /error-guessing [--file="path/to/output.md"] ``` **Modes:** | Mode | Syntax