State Transition Testing Skill: Derive Reachable and Abnormal Paths from Real Rules
A state diagram is a design artifact, not a record that every transition can happen. Useful state-transition testing preserves the rule, the guard, the target state, and what still needs runtime evidence.
Why this Skill is needed
The State Transition Testing Skill derives candidates for reachable, unreachable, and abnormal transitions from supplied states, events, guards, actions, roles, and persistence evidence. It does not execute tests or claim coverage.
What the Skill does
The output is a candidate path with evidence boundaries, not a fabricated state machine.
Use this Skill when a workflow such as order, subscription, approval, or incident handling has state-dependent behavior that needs traceable test-design candidates.
A good STT-## finding includes source state, event, precondition or guard, action, target state, reachability, evidence, impact, owner, close condition, and validation method.
Use it when a state model is changing, abnormal transitions matter, or a team needs to identify unreachable or unverified paths before writing cases.
What it does not do
The State Transition Testing Skill can organize material, evidence, and next actions for Transition candidate. It does not replace:
- Confirmation of rules, scope, and risk by the accountable domain owner.
- A real environment, account, dataset, log, or run record; static analysis does not become runtime evidence by itself.
- Authorization for release, compliance, production actions, or residual-risk acceptance.
- A Human decision when supplied sources conflict.
What it checks
The value of this Skill is not another keyword list. It connects each focus area to an observable input, a judgment, and a way to close the loop. Start with a small matrix based on the source Skill’s output contract:
| Focus | Question before analysis | Handoff output |
|---|---|---|
| Transition candidate | Source, event, guard, action, and target | STT ID and source |
| Reachability | Reachable, unreachable, unknown, or abnormal candidate | Evidence state |
| Persistence concern | What must remain consistent after transition | Data and side effect |
| Validation action | State setup and smallest safe check | NOT_RUN until executed |
If a row has only a conventional expectation and no source or validation method, keep it open instead of turning it into a pass.
Audit inputs before you start
Before analyzing Transition candidate, classify the input into six evidence states. A gap is not automatically a failure, but it must not disappear inside the conclusion.
| State | Meaning | How this Skill should handle it |
|---|---|---|
| known | Directly supported by the supplied material | Keep the source, version, and time with the judgment |
| missing | Needed for this pass but not supplied | Name the smallest evidence action and limit the conclusion |
| conflicting | Sources disagree | Show both sources and route the conflict to an owner |
| stale | Present but outside the relevant version or time window | Mark freshness; old evidence is not current proof |
| out_of_scope | Related but excluded from this pass | Keep the boundary explicit |
| assumptions | Temporarily adopted to continue analysis | State how and when the assumption will be checked |
Keep the input version, scope, environment, evidence locations, and accountable owner together. Without a run record, deliver analysis, design, or a validation plan—not an execution pass.
From problem to structured Finding
Connect the source, scope, evidence state, analysis, owner, action, close condition, and validation before writing the conclusion. The case below keeps this Skill’s identifier and domain context.
Keep the decision layers separate
For Transition candidate, do not compress four different kinds of language into “recommended to pass”:
| Layer | How to write it | Application here |
|---|---|---|
| Fact | What the supplied material directly shows | Cite the source, version, input, or run record for the focus |
| Evidence-backed Inference | What several facts support together | Show the inference chain and retain uncertainty |
| Recommendation | The smallest next action | Name the evidence, review, execution, or regression path |
| Human Decision | What an accountable person must decide | Leave scope, risk acceptance, resources, and release meaning to the owner |
A complete case
This case follows Input, Analysis, Finding, Decision, and Validation. When material is incomplete, keep missing, conflicting, or assumptions visible instead of turning them into a pass.
Input
| Material | What to provide | What to do when it is missing |
|---|---|---|
| State source | State model, workflow, API contract, or domain decision | Do not invent missing states |
| Events and guards | Triggers, preconditions, roles, permissions, and timing | Keep unknown guards unassessed |
| Actions and persistence | Side effects, durable state, retries, and error transitions | Separate design from observed behavior |
| Validation context | Environment, data, state setup, and run evidence | Mark candidates NOT_RUN without execution |
Use a request like this:
Use the state-transition-testing Skill.
Task: Derive test candidates for an order moving from pending payment to paid, failed, cancelled, or refunded.
Inputs: [state model, payment events, role rules, retry behavior, persistence notes]
Scope: [checkout staging, card payment flow]
Constraints: [do not invent states or claim all paths executed]
Produce STT-## findings with state, event, guard, action, target, reachability, source evidence, impact, owner, close condition, and validation.Analysis
Use the input, matrix, and evidence state to form the judgment before writing the Finding; keep missing material as a gap.
Finding
Focused example: Derive payment failure and refund paths without inventing rules
The model shows pending payment can become paid or failed, but says nothing about a timeout after provider authorization. The Skill should preserve the missing guard and ask whether the state is failed, pending-review, or another approved state. It should not add a timeout state because it is common in payment systems.
The result is a traceable test-design inventory. It does not prove reachability, execution, coverage, or release readiness.
Example finding: turn one problem into a handoff
The field example below shows the recording pattern; it is not an execution result.
If the supplied material cannot prove that Transition candidate meets its contract, write the finding like this. It does not invent the missing rule or turn missing evidence into a failure.
| Field | Example wording |
|---|---|
| Source and scope | Record the requirement, version, environment, and the concrete object for Transition candidate |
| Finding | The condition or result for Transition candidate is not yet traceable to evidence |
| Evidence state | missing / assumptions; use conflicting when sources disagree |
| Impact and priority | Name the affected user, journey, or delivery decision without inflating severity |
| Owner and Human decision | Ask the product, engineering, security, or test owner to confirm the rule and trade-off |
| Action and close condition | Add the smallest missing evidence; close only when source, judgment, and owner can be reviewed |
| Validation | Name one repeatable check, query, or run and retain the raw artifact |
The point is to let the next person walk from the finding back to the source and run an action that can change the decision.
Decision
The accountable owner confirms the decision question and risk trade-off; the Skill does not make that choice.
Validation
Before closing the finding, run the stated validation and retain the raw artifact. Without an execution record, the status remains unverified.
How a Finding enters the next stage
Handoff output
| Output field | Why it exists | Example status |
|---|---|---|
| Transition candidate | Source, event, guard, action, and target | STT ID and source |
| Reachability | Reachable, unreachable, unknown, or abnormal candidate | Evidence state |
| Persistence concern | What must remain consistent after transition | Data and side effect |
| Validation action | State setup and smallest safe check | NOT_RUN until executed |
Every conclusion should point to a source, evidence state, and next action. If evidence is missing, use pending, blocked, unassessed, or NOT_SCORED instead of filling the gap with confidence.
Next-stage route
At minimum, hand off the source, evidence state, owner, close condition, and validation action; the next-stage conclusion remains bounded by the evidence state.
How to prepare better input
Provide the authoritative state source, events, guards, roles, actions, persistence rules, versions, environment, and known runtime traces. Unknown rules stay unassessed or blocked.
A useful handoff includes input versions, scope, time window, evidence index, assumptions, Human decision boundary, and the smallest validation action.
Working with other Skills
- Decision Table Testing:organizes condition and outcome combinations.
- Business Rule Extraction:recovers explicit rules before transition design.
- Test Scope Analysis:keeps transition scope and exclusions visible.
Common traps
- Treating a static diagram as proof that every arrow is executable.
- Filling missing states and guards from domain convention.
- Calling candidate count coverage or pass evidence.
Install and invoke
npx skills add https://github.com/naodeng/awesome-qa-skills/tree/main/skills/en/testing-types/state-transition-testing -gUse the state-transition-testing Skill.
Include objective, scope, versions, evidence paths, constraints, and decision boundary.
Audit inputs first, preserve evidence states, and finish with owner, close condition, and validation method.FAQ
Can the Skill write full test cases?
It can derive traceable candidates, but it should not expand into a complete strategy or execution result.
What does NOT_RUN mean here?
The transition is identified but has no authorized runtime evidence. Keep it separate from unreachable or passed.
The Skill is most useful when attached to one real project artifact and kept with its source evidence. Start narrow, validate the uncertain part, and expand only when evidence supports it.
References
Source Skill and execution contract
The complete execution contract lives in State Transition Testing prompt. The source directory may also contain evaluation cases and supporting material.
Static plans, file presence, and dry runs keep their evidence state. They do not become runtime proof, an all-passed claim, or release approval.
Reference links
- State Transition Testing prompt:https://github.com/naodeng/awesome-qa-skills/tree/main/skills/en/testing-types/state-transition-testing/prompts/state-transition-testing.md
- State Transition Testing Skill source:https://github.com/naodeng/awesome-qa-skills/tree/main/skills/en/testing-types/state-transition-testing
- State Transition Testing details:https://inaodeng.com/en/qaskills/state-transition-testing/
- Awesome QA Skills on GitHub:https://github.com/naodeng/awesome-qa-skills