scaffold-aggregate

name	scaffold-aggregate
description	Phase 2 driver — fully scaffold one aggregate: create all files, add snapshot fields, add all intra-invariants, register in BeanConfigurationSagas, run creation test. Reads details from plan.md and the aggregate-grouping template. Arguments: "<AggregateName>"

Scaffold Aggregate: $ARGUMENTS

You are completing all Phase 2 work for the aggregate named in $ARGUMENTS. Do all five steps in order. Tick the corresponding checkbox in plan.md immediately after each step succeeds. Do not stop early.

---

Step 0 — Gather context

Read before writing any code:

1. plan.md — find the ### <AggregateName> section. Extract:
   • The snapshot fields bullet (fields to cache and which events trigger them)
   • The intra-invariants bullet (list of rule names to add)
2. The aggregate-grouping template (*-aggregate-grouping.md) — find §2 for this aggregate. Authoritative source for snapshot field names, types, and event triggers.
3. The domain model template (*-domain-model.md) — §3.1 and §3.2 rules for this aggregate, needed to understand invariant semantics.

---

Step 1 — Create aggregate files

Read .claude/skills/scaffold-aggregate/create-aggregate.md and follow every step in it for $ARGUMENTS. This produces the base class, SagaXxx, factories, repositories, service stub, and command handler stub.

Tick in plan.md:

• Scaffolded (/scaffold-aggregate <AggregateName> — Step 1)

---

Step 2 — Add snapshot entity classes and/or snapshot fields

Read the plan.md entry for this aggregate — it lists exactly which checkboxes apply. Two patterns:

• Pattern A — Scalar: Add the field(s) directly on the base aggregate class under a // --- Snapshot fields --- comment. Initialise to null/0. Copy in the copy constructor.
• Pattern B — Structured / collection: Follow create-aggregate.md Step 1b — it contains all implementation details (entity class structure, JPA annotations on both the new class and the parent aggregate, canonical references).

If the aggregate has no snapshot data (root publisher), skip this step. Do not wire event subscriptions yet — that is Phase 4 (/wire-event).

Tick all applicable checkboxes in plan.md for this step:

• Snapshot entity classes created: (if Pattern B applies)
• Snapshot fields/references added to aggregate class

---

Step 3 — Add intra-invariants

Read .claude/skills/scaffold-aggregate/add-invariant.md. For each rule name listed in the plan.md intra-invariants bullet for this aggregate, follow the instructions in that file once per rule. Derive each rule's meaning from its name and the domain model template.

After all rules are added:

Tick in plan.md:

• Layer 1 intra-invariants added:

---

Step 4 — Register in BeanConfigurationSagas

Open src/test/groovy/.../BeanConfigurationSagas.groovy and add three beans for this aggregate, following the style of existing declarations in the file:

@Bean
<AggregateName>Repository <aggregateName>Repository() { new Sagas<AggregateName>Repository() }

@Bean
<AggregateName>Factory <aggregateName>Factory(<AggregateName>Repository repo) {
    new Sagas<AggregateName>Factory(repo)
}

@Bean
<AggregateName>Service <aggregateName>Service(
        SagaUnitOfWorkService uowService,
        <AggregateName>Repository repo,
        <AggregateName>Factory factory) {
    new <AggregateName>Service(uowService, repo, factory)
}

Tick in plan.md:

• Registered in BeanConfigurationSagas.groovy

---

Step 5 — Run the creation test

Write the T1 creation test at src/test/groovy/.../sagas/<aggregate>/<AggregateName>Test.groovy. Follow the T1 template in docs/concepts/testing.md: one happy-path case + one failing case per intra-invariant added in Step 3. If no intra-invariants exist, only happy-path case.

Then run:

cd applications/<appName>
mvn clean -Ptest-sagas test -Dtest=<AggregateName>Test

Diagnose and fix any failures before ticking. Do not move on until the test is green.

Tick in plan.md:

• Creation test passes (<AggregateName>Test)

---

Done

All five sub-steps are checked off. Report:

• Aggregate scaffolded: list files created
• Snapshot fields: list field names (or "none")
• Intra-invariants: list rule names added
• Registered in BeanConfigurationSagas
• Creation test: green