NestJS-Spelunker

Description

This module does a bit of a dive through the provided module and reads through the dependency tree from the point of entry given. It will find what a module imports, provides, has controllers for, and exports and will recursively search through the dependency tree until all modules have been scanned. For providers if there is a custom provider, the Spelunker will do its best to determine if Nest is to use a value, a class/standard, or a factory, and if a factory, what value is to be injected.

Options

As of now, the module expects two values in its static explore method: an INestApplication, obtained by using NestFactory.create(), and an optional LoggerService. If no logger is provided, a Nest Logger with the context "SpelunkerModule" will be created.

Usage

Much like the SwaggerModule, the SpelunkerModule is not a module that you register within Nest's DI system, but rather use after the DI system has done all of the heavy lifting. Simple usage of the Spelunker could be like:

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  SpelunkerModule.explore(app);
  app.listen(3000);
}

The SpelunkerModule will not get in the way of application bootstrapping, and will still allow for the server to listen.

Sample Output

Currently, the SpelunkerModule only logs to the terminal, though this is temporary and will eventually be to a file so that everything can be stylized. For now, this is a sample of the output:

{
  "AppModule": {
    "imports": [
      "AnimalsModule"
    ],
    "providers": {
      "AppService": {
        "method": "standard"
      }
    },
    "controllers": [
      "AppController"
    ],
    "exports": []
  },
  "AnimalsModule": {
    "imports": [
      "DogsModule",
      "CatsModule",
      "HamstersModule"
    ],
    "providers": {},
    "controllers": [],
    "exports": []
  },
  "DogsModule": {
    "imports": [],
    "providers": {
      "DogsService": {
        "method": "standard"
      }
    },
    "controllers": [
      "DogsController"
    ],
    "exports": []
  },
  "CatsModule": {
    "imports": [],
    "providers": {
      "CatsService": {
        "method": "standard"
      }
    },
    "controllers": [
      "CatsController"
    ],
    "exports": []
  },
  "HamstersModule": {
    "imports": [],
    "providers": {
      "HamstersService": {
        "method": "factory",
        "injections": []
      }
    },
    "controllers": [
      "HamstersController"
    ],
    "exports": []
  }
}

In this example, AppModule imports AnimalsModule, and AnimalsModule imports CatsModule, DogsModule, and HamstersModule and each of those has its own set of providers and controllers.

Caution

This package is in early development, and any bugs found or improvements that can be thought of would be amazingly helpful. You can log a bug here, and you can reach out to me on Discord at PerfectOrphan#6003.

fjodor-rybakov / nestjs-spelunker