inversify-di

name	inversify-di
description	Inversify dependency injection patterns for the server. Use when creating or modifying DI container bindings, adding injectable services, writing tests with dependency overrides, or managing TYPES symbols.

Inversify DI

TYPES Registry

File: apps/server/src/types.ts

export const TYPES = {
  RunnerFactory: Symbol.for('RunnerFactory'),
  SessionStore: Symbol.for('SessionStore'),
  RawEventStore: Symbol.for('RawEventStore'),
  ChatHandler: Symbol.for('ChatHandler'),
  Database: Symbol.for('Database'),
  UsageTracker: Symbol.for('UsageTracker'),
  SettingsStore: Symbol.for('SettingsStore'),
  ChannelManager: Symbol.for('ChannelManager'),
} as const;

Container Setup

File: apps/server/src/container.ts — createContainer(options)

All bindings are inline (no ContainerModule pattern):

Symbol	Binding	Scope
RunnerFactory	.toConstantValue(factory)	—
Database	.toConstantValue(db)	—
SessionStore	.toConstantValue(store)	—
RawEventStore	.toConstantValue(store)	—
SettingsStore	.toConstantValue(store)	—
ChannelManager	.toConstantValue(mgr)	—
UsageTracker	.to(UsageTracker).inSingletonScope()	Singleton
ChatHandler	.to(ChatHandler).inSingletonScope()	Singleton

Only ChatHandler and UsageTracker use @injectable() + @inject().

Injectable Services

// apps/server/src/socket/chat-handler.ts
@injectable()
export class ChatHandler implements HandlerContext {
  constructor(
    @inject(TYPES.RunnerFactory) public runnerFactory: RunnerFactory,
    @inject(TYPES.RawEventStore) public rawEventStore: RawEventStore,
    @inject(TYPES.SessionStore) public sessionStore: SessionStore,
    @inject(TYPES.UsageTracker) public usageTracker: UsageTracker,
    @inject(TYPES.ChannelManager) public channelManager: ChannelManager,
    @inject(TYPES.SettingsStore) @optional() settingsStore?: SettingsStore,
  ) {}
}

HandlerContext Interface

File: apps/server/src/socket/handler-context.ts

Aggregates all injected services. Socket handlers access dependencies through this interface.

Composite Store Pattern

buildStores() in container.ts creates stores based on StoreConfig, wrapping multiple backends in CompositeRawStore / CompositeSessionStore when needed.

Testing

File: apps/server/src/test/create-test-container.ts

export function createTestContainer(overrides): Container {
  const container = createContainer({ ...overrides, storeConfig: { sqlite: true } });
  const db = container.get<DrizzleDatabase>(TYPES.Database);
  migrate(db, { migrationsFolder });
  container.rebindSync<SettingsStore>(TYPES.SettingsStore)
    .toConstantValue(new InMemorySettingsStore());
  return container;
}

Key test methods:

• container.get<T>(TYPES.X) — retrieve service
• container.rebindSync<T>(TYPES.X).toConstantValue(mock) — replace binding

Adding a New Service

1. Add symbol to TYPES in apps/server/src/types.ts
2. If constructor-injectable: add @injectable() + @inject() decorators
3. If constant-bound: instantiate and .bind(TYPES.X).toConstantValue(instance)
4. Add to test container if tests need it

---

Inversify v8 Breaking Changes

Reference: https://inversify.io/docs/guides/migrating-from-v7/

API Renames

v7	v8
container.loadSync(module)	container.load(module)
container.load(module)	container.loadAsync(module)
container.rebindSync<T>(id)	container.rebind<T>(id) (now sync by default)
container.isBoundNamed(id, name)	container.isBound({ serviceIdentifier: id, named: name })
container.isBoundTagged(id, key, val)	container.isBound({ serviceIdentifier: id, tag: { key, value: val } })

Removed APIs

• rebindSync is gone — rebind is now synchronous by default in v8; update all call sites.
• toProvider() is removed — replace with toFactory() using an async inner function if you need a promise-returning factory.

Module System

• v8 is ESM-only. CommonJS (require) is no longer supported.

Service Identifiers

• Plain functions are no longer valid service identifiers. Use string or Symbol (e.g., Symbol.for('MyService')) instead. Abstract classes are still valid.

Migration Tip for This Project

The test container currently calls container.rebindSync (v7). When upgrading to v8, rename all rebindSync calls to rebind.