NestJS + gRPC + step by step guide + e2e tests

What is RPC and how you can use it in NestJS is the question I had in mind to answer in this post. Sit tight for a short, concise, and precise intro to this world:

So RPC,

• Stands for Remote Procedure Call.
• It's a communication mechanism.
• It's almost the same as though we have access to the methods/function defined in another program.
• Can be used for inter-service communications.
• Supper efficient.

[!CAUTION]

This is still a network call. So do not call it like your codes who are living in the same codebase.

[!NOTE]

We can use any application level protocol for sending requests and receiving responses:

• TCP: HTTP1, HTTP2.
• UDP.
• Websockets.
• etc.

This means that it is like GraphQL transport layer agnostic. You can use whatever you like.

gRPC

Now let's demystify the gRPC. It's:

• An open-source rewrite of RPC used by Google.
• Why gRPC?
  1. It uses only HTTP2 as its transport layer.
  2. Protocol buffer as our data exchange format.
• No browser support yet, but a good thing to have for inter-service communication in a microservice architecture.

NestJS

I love NestJS and how good it is at giving you're code more structure. So here is how you can get up to speed with it.

1. Follow the official documentation opn how to bootstrap a NestJS app + gRPC.

   pnpx create-nx-workspace grpc --preset=nest --appName nestjs-client --bundler esbuild --packageManager pnpm --nxCloud skip

1. I also love perfectionist for a good reason and that is the tidiness it gives you for little conf, so I highly recommend you take a look at it in their official doc.

Or if you're looking for something on how to get up to speed I guess this commit can be a real quick intro to how to use it. BTW I appreciate it if you give my repo a star in case it was helpful 🙂.

   nx run-many -t lint --fix

1. Write you're protobuf file like what I did here at user.proto.
2. Use the ts-proto to auto generate the interfaces and decorators for your gRPC controller.

   {
     "scripts": {
       "grpc:gen": "npx protoc --plugin=./node_modules/.bin/protoc-gen-ts_proto --ts_proto_opt=fileSuffix=.interface --ts_proto_opt=nestJs=true --ts_proto_opt=addNestjsRestParameter=true --ts_proto_out={projectRoot}/src/assets/interfaces -I {projectRoot}/src/assets/ {projectRoot}/src/assets/*.proto"
     }
   }

For the complete solution look at this.

1. Now just run the npm run grpc:gen or if you're using Nx just run nx grpc:gen projectName.

2. Congrats, you have your types and decorators. So let's put them into use.

[!TIP]

For a complete example look at the nestjs-client.

Ref

BTW you can find a working example in this repo too, so if this post was useful to you consider sharing it, giving my repo a star and this post a like.

kasir-barati / nestjs-materials

NestJS tips, tricks, Notes, Things which are not in doc and I used to figure them out and use them

Important

Keep this file synchronized with index.md.

nestjs-materials

NestJS tips, tricks, Notes, Things which are not in doc and I used to figure them out and use them

• Microservices
  • gRPC.
  • Protobuf.
• How to debug your code and flaky tests.
  • A Crude Debug Mode For a Dockerized NestJS App.
• Designing and versioning RESTful APIs.
  • Pagination.
• MockServer and mocking 3rd-party HTTP/S calls.
• Kafka intro.
• RabbitMQ intro.
• NestJS and GraphQL with nestjs-query

View on GitHub

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