This chapter follows Testing NestJS applications. It closes the NestJS series.
Application graph
The internal map of every module, provider, and controller, built from module metadata at startup and used to resolve each injection. See What is NestJS.
Platform adapter
The package that connects Nest to an HTTP library: @nestjs/platform-express by default, or @nestjs/platform-fastify. See What is NestJS.
Module
A class with @Module() that declares its controllers and providers, the modules it imports, and the providers it exports. See Modules in NestJS.
Root module
The module passed to NestFactory.create(), usually AppModule. Only modules reachable from it are loaded. See Modules in NestJS.
Feature module
A module that groups the controller, service, and DTOs of one business area. See Modules in NestJS.
Global module
A module marked @Global() whose exports are injectable everywhere without an import. See Modules in NestJS.
Dynamic module
A module configured by a static method such as forRoot(), forFeature(), or register() that returns module metadata built from options. See Dynamic modules in NestJS.
Controller
A class with @Controller() whose methods handle routes and return the response body. See Controllers in NestJS.
Route handler
The controller method bound to one HTTP method and path, for example by @Get(':id'). See Controllers in NestJS.
DTO
Data transfer object: a class describing the shape of request data, usually with class-validator decorators. See Controllers in NestJS.
Provider
Anything Nest can inject: a service class, a value, or the result of a factory, registered in a module’s providers. See Providers and dependency injection in NestJS.
Injection token
The key a provider is registered and looked up under: the class itself, a string, or a symbol used with @Inject(). See Providers and dependency injection in NestJS.
Custom provider
A provider registered in long form with useClass, useValue, useFactory, or useExisting. See Providers and dependency injection in NestJS.
Injection scope
How long a provider instance lives: once per application (DEFAULT), per request (REQUEST), or per consumer (TRANSIENT). See Providers and dependency injection in NestJS.
Request lifecycle
The fixed order in which middleware, guards, interceptors, pipes, the handler, and exception filters process a request. See The NestJS request lifecycle.
Binding scope
The level a guard, interceptor, pipe, or filter is attached at: global, controller, route, or, for pipes, parameter. See The NestJS request lifecycle.
ExecutionContext
The object passed to guards and interceptors that exposes the request, the handler, and the controller class. See Guards in NestJS.
Middleware
A function or class that runs before routing and can change the request or end the response. See Middleware in NestJS.
Guard
A class implementing CanActivate that decides whether a request may reach the handler. See Guards in NestJS.
Reflector
The helper that reads metadata set by decorators such as @Roles() from a handler or controller class. See Guards in NestJS.
Interceptor
A class implementing NestInterceptor that wraps the handler call and can act on the request before it and on the result after it. See Interceptors in NestJS.
Pipe
A class implementing PipeTransform that transforms or validates one handler argument. See Pipes and validation in NestJS.
ValidationPipe
The built-in pipe that validates request data against a DTO’s class-validator decorators. See Pipes and validation in NestJS.
Exception filter
A class implementing ExceptionFilter that turns a thrown exception into a response. See Exception filters in NestJS.
HttpException
The base class for exceptions that carry an HTTP status, such as NotFoundException. See Exception filters in NestJS.
ConfigService
The injectable service from @nestjs/config that reads environment variables and loaded configuration. See Configuration in NestJS.
Lifecycle hook
A method such as onModuleInit() or onApplicationShutdown() that Nest calls at a fixed point during startup or shutdown. See Application lifecycle hooks in NestJS.
Passport strategy
A class extending PassportStrategy() that checks one kind of credential, such as a password or a JWT, and returns the user. See Authentication in NestJS.
Testing module
A module built with Test.createTestingModule() that resolves dependencies like the real app but lets a test override any provider. See Testing NestJS applications.