Runnable Suites examples for NestJS, Inversify, and InjectionJS with Jest or Vitest. Each example uses the same user management domain to demonstrate solitary tests, sociable tests, and a mocked database boundary.

Use Node.js ^22.22.2 || ^24.15.0 || ^26.0.0 and pnpm 12.16.1. From this repository:

cd nestjs-jest
pnpm install --frozen-lockfile --strict-peer-dependencies
pnpm test

Each example installs the published Suites v4 packages from npm. No source checkout, local tarballs, or preparation step is needed. pnpm test checks TypeScript declarations with skipLibCheck: false, then runs the tests.

New to Suites? Start with Installation and Quickstart.

The advanced example focuses on .mock().final() and .mock().impl(). InjectionJS examples also demonstrate InjectionToken overrides and identity: two tokens with the same description remain different dependencies.

These examples use the framework versions above. Suites also supports NestJS 10/11 and Inversify 7; the Unit repository tests the full supported framework matrix. This repository's CI runs all seven examples on Node 22, 24, and 26, giving 21 jobs.

The examples use @suites/unit, Jest/Vitest doubles, and the InjectionJS adapter at 4.1.0. The NestJS and Inversify adapters use 4.0.1. Shared packages follow Suites' independent versioning; not every package changes in each release.

suites-versions.json records the expected versions, including transitive packages. Each example has its own lockfile. Check an installation from the repository root:

node scripts/verify-suites.mjs nestjs-jest

The verifier checks installed Suites versions, absence of postinstall declaration patching, and the configured adapter declarations. When upgrading, update the package manifests and version record together, regenerate each lockfile, and run every example.

Each example includes global.d.ts with exactly one doubles /unit reference and one DI /metadata reference. For NestJS with Jest:

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

Use @suites/doubles.vitest/unit for Vitest, @suites/di.inversify/metadata for Inversify, or @suites/di.injectionjs/metadata for InjectionJS. Keep these declarations included in the test tsconfig. Suites no longer patches declarations during postinstall.

Import TestBed, Mocked, and Stub from @suites/unit after loading the declarations. Standalone mock() and stub() helpers come from the doubles adapter. See the v3 to v4 migration guide for existing projects. Sinon is no longer supported.

Solitary tests construct one class with all dependencies mocked:

const { unit, unitRef } = await TestBed.solitary(UserService).compile();

Sociable tests keep selected collaborators real and mock external I/O:

const { unit, unitRef } = await TestBed.sociable(UserService)
  .expose(UserValidator)
  .expose(UserRepository)
  .compile();
const database = unitRef.get<Database>(DATABASE_TOKEN);

Every example uses this dependency graph:

graph LR
    UserService --> UserValidator
    UserService --> UserRepository
    UserRepository --> DATABASE_TOKEN

Application code lives in src/; runnable tests live in tests/. Tests build a fresh TestBed for each scenario to avoid sharing mock state.

The adapter supports constructor injection with InjectionJS ^2.6.1. Contextual inject() calls, provider factories, multi-providers, and production injector hierarchy rules are outside its scope. Optional constructor dependencies are mocked unless explicitly overridden.

The Vitest example externalizes injection-js through test.server.deps.external so the adapter and test code share decorator and token identities. Keep this setting when copying its configuration.

• Missing decorator metadata: Keep experimentalDecorators and emitDecoratorMetadata enabled, use the included SWC transform, and load reflect-metadata before decorated classes.
• Missing Mocked or token types: Check global.d.ts and the test tsconfig's include paths. Do not combine multiple DI or doubles augmentations in one TypeScript project.
• Installation errors: Use a supported Node line and pnpm 12.16.1. Install inside the selected example directory.
• InjectionJS token not found: Import the original token instance. Recreating a token with the same description does not identify the same dependency.

• Solitary tests
• Sociable tests
• Mock configuration
• InjectionJS guide