EnhancerMetadataCacheEntry

Kind: Interface

Source: packages/core/inspector/interfaces/enhancer-metadata-cache-entry.interface.ts

Part of: Core

EnhancerMetadataCacheEntry describes a cached metadata record for an enhancer discovered by the NestJS inspector. It links an enhancer—such as a guard, interceptor, pipe, or filter—to its target node, owning module, class or method, and resolved instance wrapper. The inspector uses these entries to efficiently associate enhancer metadata with the serialized dependency graph.

Properties

Diagram

mermaid
graph LR
  Target[Target Node<br/>targetNodeId] --> Entry[EnhancerMetadataCacheEntry]
  Module[Module<br/>moduleToken] --> Entry
  Class[Controller or Provider<br/>classRef] --> Entry
  Method[Optional Method<br/>methodKey] --> Entry
  Enhancer[Enhancer Metadata<br/>enhancerRef] --> Entry
  Wrapper[InstanceWrapper<br/>enhancerInstanceWrapper] --> Entry
  Subtype[EnhancerSubtype<br/>Guard / Pipe / Filter / Interceptor] --> Entry

Usage

ts
import { Type } from '@nestjs/common';
import { InstanceWrapper } from '../../injector/instance-wrapper';
import { EnhancerSubtype } from '../enums/enhancer-subtype.enum';
import { EnhancerMetadataCacheEntry } from '../interfaces/enhancer-metadata-cache-entry.interface';

function cacheEnhancer(
  entry: EnhancerMetadataCacheEntry,
  cache: Map<string, EnhancerMetadataCacheEntry[]>,
) {
  const entries = cache.get(entry.targetNodeId) ?? [];

  entries.push(entry);
  cache.set(entry.targetNodeId, entries);
}

const entry: EnhancerMetadataCacheEntry = {
  targetNodeId: 'controller:users',
  moduleToken: 'UsersModule',
  classRef: UsersController as Type,
  methodKey: 'findAll',
  enhancerRef: AuthGuard,
  enhancerInstanceWrapper: authGuardWrapper as InstanceWrapper,
  subtype: EnhancerSubtype.GUARD,
};

cacheEnhancer(entry, enhancerMetadataCache);

AI Coding Instructions

• Preserve the relationship between targetNodeId, moduleToken, and enhancerInstanceWrapper; these values identify where an enhancer belongs in the inspected graph.
• Treat methodKey as optional: undefined indicates a class-level enhancer rather than a method-level enhancer.
• Use subtype to distinguish enhancer categories when serializing or grouping metadata; do not infer the category solely from enhancerRef.
• Keep enhancerRef typed as unknown unless the consuming code has safely narrowed its runtime shape.
• When adding cache entries, avoid replacing existing entries for the same target node because multiple enhancers may apply to one controller or method.

Relationships

• IMPORTS → Type
• IMPORTS → EnhancerSubtype