Types

Suites uses your selected adapters to type mocks and dependency identifiers. In v4, load those declarations explicitly in a file included by your test tsconfig.

Configure module augmentation

For NestJS + Jest:

/// <reference types="@suites/doubles.jest/unit" />
/// <reference types="@suites/di.nestjs/metadata" />

Use @suites/doubles.vitest/unit for Vitest. Choose @suites/di.inversify/metadata for Inversify or @suites/di.injectionjs/metadata for InjectionJS (Suites 4.1 or later). Include exactly one doubles reference and one DI reference per test TypeScript project.

Installing an adapter alone does not load these augmentations. Suites 4 has no postinstall script that patches your declarations. See Type Reference Configuration for the tsconfig setup.

Mocked<T>

A deeply mocked type: methods gain the selected library’s mock API, and nested properties are mocked recursively. Import it as a type from @suites/unit after loading the doubles augmentation.

import type { Mocked } from '@suites/unit';
import { mock } from '@suites/doubles.jest';

interface User {
  id: string;
}

interface UserRepository {
  find(id: string): Promise<User>;
  cache: { clear(): void };
}

const repository: Mocked<UserRepository> = mock<UserRepository>();
repository.find.mockResolvedValue({ id: '1' });
repository.cache.clear.mockReturnValue(undefined);

With Vitest, change the runtime mock import to @suites/doubles.vitest. The Mocked type import stays the same. unitRef.get() also returns the selected adapter’s mocked type.

Stub<TArgs>

Represents an individual mock function, with its argument tuple typed by TArgs:

import type { Stub } from '@suites/unit';
import { stub } from '@suites/doubles.jest';

const onMessage: Stub<[string]> = stub();
onMessage('ready');
expect(onMessage).toHaveBeenCalledWith('ready');

The /unit declaration supplies Mocked, Stub, and typed methods for UnitReference and MockOverride. It does not add runtime mock() or stub() exports to @suites/unit; import those functions from your doubles adapter.

Dependency identifier metadata

The DI /metadata reference augments IdentifierMetadataRegistry in @suites/types.di:

For Inversify, select a named dependency with unitRef.get(Repository, { named: 'primary' }). Use the same metadata when configuring .mock(Repository, { named: 'primary' }).

Custom DI adapters can augment IdentifierMetadataRegistry with their own metadata type. Load only the adapter declarations belonging to that test project.

Adapter-registered dependency tokens

Since Suites 4.1, InjectableIdentifier<T> from @suites/types.di includes class constructors, strings, symbols, and types registered by your DI adapter through InjectableIdentifierRegistry<T>.

Loading @suites/di.injectionjs/metadata registers InjectionJS’s InjectionToken<T>. Supply an explicit dependency type when configuring or retrieving its mock:

// USER_REPOSITORY and UserRepository come from your application.
const repository = unitRef.get<UserRepository>(USER_REPOSITORY);

The token must be the same instance used by the constructor’s @Inject() decorator. Two tokens with the same description remain distinct. See the InjectionJS guide for the complete example.

Custom adapters use InjectableIdentifierRegistry<T> for token types and IdentifierMetadataRegistry for metadata types. These are separate extension points; registering a token type does not implement runtime reflection for an adapter.

See Also

• UnitReference for retrieving typed mocks
• Mock Configuration for .impl() and .final()
• Suites 3 to 4 for migration steps

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