machenjie domain-logic-implementation
Registry Trigger
Use when
- implement domain invariant transition calculation policy rule authority failure semantics and bypass protection
Do not use when
- work changes orchestration persistence transport or model translation without changing domain behavior
Skill Role
Implement the authority that accepts or rejects reachable state transitions, calculations, or policy results. Select aggregates, value objects, policies, or domain services only when their authority fits.
High-Value Rules
- Select the authority that has the facts and lifecycle needed to reject an invalid decision for reachable callers. Object type, framework convention, or method size does not determine ownership.
- Scan API, admin, import, job, consumer, migration, fixture, ORM, and direct-write paths that can create or mutate the affected state. Record uninspected writers instead of assuming the named method is exclusive.
- Reject invalid state before durable or external effects through selected constraints, locks, versions, or idempotency that reinforce readable domain behavior.
- Define transitions and calculations with trusted inputs, allowed and denied outcomes, basis/version, units, precision, rounding, currency/timezone/effective-time semantics, and terminal behavior that the task actually changes.
- Return domain decisions, typed denials, or domain events without performing persistence, provider calls, queueing, file I/O, cache mutation, or transport mapping inside the rule authority.
- When a rule spans consistency boundaries, name the application, transaction, idempotency, compensation, or reconciliation owner. Do not claim a single aggregate guarantee that no local authority can enforce.
- Account for existing persisted values, old and new rule versions, replay, backfill, projections, and external consumers when rule evolution can reinterpret historical state.
Anti-Patterns
- Using controller, UI, service prechecks, fixtures, or ORM hooks as the final protection for a business invariant.
- Creating a domain service, value object, or aggregate because a pattern catalog suggests it rather than because authority and lifecycle evidence require it.
- Copying formulas, transition guards, or policy branches into reporting, mappers, jobs, and consumers.
- Treating happy-path tests or a database constraint as proof that bypasses, denials, historical data, and concurrent writes are safe.
Stop Conditions
- Escalate when rule truth or authority is disputed, or a cross-boundary invariant has no consistency owner. Also escalate when historical data violates the new rule, or money, permission, entitlement, inventory, compliance, or irreversible state lacks denied and recovery semantics.
Output Contract
- Return a domain-rule contract: state authority, invariants, transitions, calculations, typed outcomes, bypasses, evolution defenses, evidence limits, and consistency owners
Targeted References
| Path | Type | Load when | Do not load when | Required by | Required output |
|---|---|---|---|---|---|
| benchmarks and patterns | benchmark-pattern | Rule authority lifecycle calculation cross-boundary consistency or evolution leaves competing placements | Current facts and reachable writers select one bounded authority | task-agent, analysis-agent | option-comparison, selected-approach |
| checklist | decision-checklist | A rule change crosses writers denials calculations concurrency defenses historical data or consumers | No invariant transition calculation policy or existing-state interpretation changes | task-agent, analysis-agent | checklist-result, residual-risk |
| evidence patterns | evidence-pattern | Authority bypass denial calculation evolution or race claims need current source and tests | Fresh scoped rule and writer evidence closes the accepted claim | task-agent, analysis-agent | evidence-record, proof-limit, residual-risk |