domain

Imported from fbuireu/forever-pto (apps/web/src/domain/AGENTS.md). Install upstream with npx skills add fbuireu/forever-pto --skill domain. Copyright stays with the author.

apps/web/src/domain

The business rules, in bounded contexts that deliberately do not follow the same rule. Nothing here renders, routes, reads a request or reaches for a browser global. The vocabulary is CONTEXT.md; a variable named for a retired term is a defect here, not a style preference.

Bounded contexts

They share no code and no types, and there is no reason for one to import the other. Premium is the only thing that connects them, and that connection lives in the application layer, not here.

Rival rules, on purpose

A reader who finds rival contracts inside one layer assumes one is a mistake. Both are intended; see ADR 0003.

calendar/ is pure. Its outside imports are a short list, and it is meant to stay that way:

• @application/dto/holiday/types: HolidayDTO and HolidayVariant
• @application/shared/utils/dates: the Temporal-backed date helpers. The arrow points the wrong way and stays that way on purpose; the alternatives cost more than the tidiness is worth, and ADR 0012 records why. The test for a new entry on this list is the runtime, not the layer: does the module resolve inside a Web Worker with no DOM and no server context
• temporal-polyfill, in utils/helpers.ts only, for PlainYearMonth.daysInMonth
• next-intl, the Locale type alone, threaded through pipeline.ts to the Metrics, where it formats month names

No @infrastructure/*, no @ui/*, no Effect. The reason is the runtime rather than taste: the planner evaluates this code inside a Web Worker with no DOM and no server context (ADR 0001). An import that touches window, process or a Node built-in breaks the planner in a way no server-side test will catch, because every test in this repo runs on the main thread.

HolidayDTO living in the application layer is a layering inversion on paper, since the type describes a Holiday, so it belongs here. It is a known exception, safe only because the file is types plus one const object. See ../application/dto/AGENTS.md.

payment/ is not pure and is not meant to be. It composes Effect programs directly against infrastructure service tags (@infrastructure/clients/*, @infrastructure/services/payments/*) and holds import type Stripe in its event factory. The tags are interfaces, so tests substitute them without a network, but the dependency on infrastructure is real, and naming it is better than pretending. Do not "fix" it by extracting repository interfaces into the domain; ADR 0003 weighed that and rejected it.

Neither rule is enforced

There is no import-boundary rule in the Biome config. Both contracts hold by review or not at all. The calendar one fails quietly: the bundle still builds, the worker throws at runtime, and useCalculationsWorker only clears the loading flag on onerror, and there is no main-thread fallback, so the user sees an empty plan and no error. That is the contract to guard.

Temporal never comes from the global

Temporal resolves from temporal-polyfill only, never the ambient global, because the global does not exist in the deployed Workers runtime and a local run proves nothing (ADR 0005). Almost all use here is indirect, through @application/shared/utils/dates.

Testing

Every module with behaviour has a co-located .test.ts, run by Vitest. A few have none and should not grow one: calendar/const.ts is a tunables object, payment/events/types.ts is types plus PAYMENT_SUCCEEDED, and payment/events/factory/resolvers.ts is covered through events.test.ts. calendar/types.ts grew one: it holds isFilterStrategy, the predicate the Web Worker narrows an incoming strategy string with, and DEFAULT_FILTER_STRATEGY, the value both that fallback and the filters store's initial state read.

• calendar/ tests take literal inputs and assert on returned values; there is nothing to mock. Those whose subject reaches getKey or createHolidaySet must call clearDateKeyCache() and clearHolidayCache() in beforeEach: the caches in calendar/utils/cache.ts are module-level and survive between cases in the same file (ADR 0006). The metrics/ subtree reaches neither and is exempt; see calendar/AGENTS.md.

• payment/ tests build a Layer.succeed(Tag, mock) for every tag the handler requires and run the program over it. No test constructs a real Stripe or Turso client.