effect-conventionslisted

# Effect-TS Conventions ## Service Pattern Every service follows Context.Tag + Layer.effect: ```typescript export interface FooService { doThing(): Effect.Effect<Result, Error> } export class Foo extends Context.Tag("Foo")<Foo, FooService>() {} export const FooLive = Layer.effect(Foo, Effect.gen(function* () { const dep = yield* SomeDependency return { doThing: () => ... } })) ``` ## Rules - Use `Layer.scoped` with `Effect.addFinalizer` for resources (DB, HTTP, processes) - Wrap `better-sqlite3` in `Effect.sync()`, NOT `Effect.tryPromise()` - Use `Effect.gen(function* () { ... })` for sequential flows - `Config.option()` returns `Option` type — check `._tag === "Some"` - Always specify error channel: `Effect.Effect<A, E>`, not `Effect.Effect<A>` - No `any` — use `unknown` and narrow - No `as` casts unless structural compatibility is proven ## Anti-Patterns - Do NOT use `await` inside Effect generators - Do NOT use `Effect.tryPromise()` for synchronous operations - Do NOT create services without a Context.Tag - Do NOT import from `effect/internal/*`