Changelog

2.0.0 (2026-11-14)

A rewrite of the resolution engine; the registration API keeps its shape. See Upgrading from 1.x to 2.0 for the upgrade steps. Earlier releases are listed in the repository changelog.

Added

• createToken<T>(name) and InjectionToken<T>: typed tokens whose resolved type is inferred. Abstract classes are accepted as tokens.
• Compile-time checks of dependency arrays against constructor parameters (when T is inferred).
• Keyed registrations accept a dependency array: addKeyedSingleton(token, Impl, key, [deps]). Keyed factories receive the key.
• Typed errors: IocError, ServiceNotFoundError (token, key, path), CircularDependencyError (path), ScopeError, RegistrationError, ValidationError (errors), DisposedError.
• has(token, key?) on the collection; isService(token, key?) on the provider is now synchronous.
• Disposal via [Symbol.asyncDispose] / [Symbol.dispose], in reverse creation order, and await using support on providers and scopes.
• validateOnBuild reports captive scoped services (with validateScopes) as well as missing dependencies.
• Detection of deadlocking concurrent resolution chains.

Changed

• Dependency counts are checked at registration (RegistrationError) instead of at resolution.
• Only class syntax is treated as an implementation; every other function is a factory.
• Keyed registrations are separate from plain ones: getService(token) never returns a keyed service.
• Every registration has its own instance, including several scoped registrations of one token.
• Concurrent resolutions of a singleton or scoped service share one instance.
• Circular dependencies resolve through a proxy for every lifetime; identity holds and #private fields work. Using a partner inside a constructor throws CircularDependencyError.
• Factories receive a provider view that carries the resolution chain; onInit runs for class registrations only.
• replace keeps the lifetime of the registration it replaces.
• remove also removes keyed registrations.
• dispose() disposes every instance, then rethrows errors instead of logging them. Values are never disposed.
• null and undefined are valid values for addValue.
• buildServiceProvider snapshots the registrations.
• ESM and CommonJS builds; Node >= 20; zero dependencies.

Removed

• removeAll(token): use remove(token).