@wisemen/nestjs-provider-explorer

Shared provider discovery utilities for NestJS packages.

This package provides:

• ProviderExplorerModule to register the explorer with Nest
• ProviderExplorer to enumerate discovered providers lazily
• NestjsProvider metadata containing providerClass, providerInstance, and the underlying Nest instanceWrapper

Installation

pnpm add @wisemen/nestjs-provider-explorer

Peer dependencies

pnpm add @nestjs/common @nestjs/core

Register The Module

Import ProviderExplorerModule into the module that needs provider discovery. It wraps Nest's DiscoveryModule, so no extra discovery setup is required.

import { Module } from '@nestjs/common'
import { ProviderExplorerModule } from '@wisemen/nestjs-provider-explorer'
import { ProviderRegistry } from './provider.registry.js'

@Module({
  imports: [ProviderExplorerModule],
  providers: [ProviderRegistry]
})
export class ProviderRegistryModule {}

Explore Providers

Inject ProviderExplorer, then iterate over providers to inspect the discovered classes and instances.

import { Injectable, OnApplicationBootstrap } from '@nestjs/common'
import { ProviderExplorer } from '@wisemen/nestjs-provider-explorer'

@Injectable()
export class ProviderRegistry implements OnApplicationBootstrap {
  constructor (
    private readonly providerExplorer: ProviderExplorer
  ) {}

  onApplicationBootstrap (): void {
    for (const provider of this.providerExplorer.providers) {
      console.info(provider.providerClass.name)
    }
  }
}

Each NestjsProvider exposes:

• providerClass: the discovered provider metatype
• providerInstance: the instantiated provider object
• instanceWrapper: Nest's internal InstanceWrapper, useful when you need to resolve transient or request-scoped providers manually

Filter Providers

The explorer returns all discovered class-based providers. Consumers are expected to filter them with their own decorators or metadata checks.

import { Injectable } from '@nestjs/common'
import { ProviderExplorer } from '@wisemen/nestjs-provider-explorer'
import { isTypesenseCollector } from './typesense-collector.decorator.js'

@Injectable()
export class TypesenseCollectors {
  constructor (
    private readonly providerExplorer: ProviderExplorer
  ) {}

  collect (): void {
    for (const provider of this.providerExplorer.providers) {
      if (!isTypesenseCollector(provider.providerClass)) {
        continue
      }

      provider.providerInstance
    }
  }
}

Scoped Providers

For singleton providers, use providerInstance directly. For transient or request-scoped providers, inspect instanceWrapper and resolve through ModuleRef when needed. This is the pattern used by packages that must defer instantiation until runtime.