RoutesMapper

Kind: Class

Source: packages/core/middleware/routes-mapper.ts

Part of: Core

RoutesMapper resolves route declarations into normalized RouteInfo objects that middleware can consume consistently. It bridges controller metadata, literal path definitions, and application routing configuration so middleware registration can target the correct HTTP paths and methods.

Methods

Where it refuses work

• RoutesMapper stops the work with an early return when !metatype, in 2 places.
• RoutesMapper stops the work with an early return when isString(controllerOrRoute).
• RoutesMapper stops the work with an early return when this.isRouteInfo(routePathOrPaths, controllerOrRoute).
• RoutesMapper stops the work with an early return when typeof version !== 'string' && Array.isArray(version).
• RoutesMapper stops the work with an early return when !moduleRefsSet.
• RoutesMapper stops the work with an early return when versioningConfig.

Diagram

mermaid
graph LR
  A[Route declaration] --> B[RoutesMapper]
  B --> C[Controller metadata]
  B --> D[Application route configuration]
  C --> E[Normalized RouteInfo[]]
  D --> E
  E --> F[Middleware registration]

Usage

ts
import { RoutesMapper } from '@nestjs/core/middleware/routes-mapper';
import { UsersController } from './users.controller';

// RoutesMapper is typically created and used internally by Nest's
// middleware subsystem with container and application configuration.
const mapper = new RoutesMapper(container, appConfig, routePathFactory);

// Resolve a controller's route metadata into middleware-ready route info.
const routes = mapper.mapRouteToRouteInfo(UsersController);

for (const route of routes) {
  console.log(route.path, route.method);
}

AI Coding Instructions

• Keep route normalization centralized in RoutesMapper; middleware code should consume RouteInfo rather than reimplementing controller metadata lookup.
• Preserve support for controller classes, path strings, and explicit route objects when changing route-resolution behavior.
• Return an empty RouteInfo[] for route declarations that cannot be resolved instead of throwing during middleware configuration.
• Ensure changes remain compatible with application global prefixes, versioning, and controller path metadata.
• Treat this class as middleware infrastructure; instantiate it through framework wiring where possible rather than constructing it ad hoc in application code.