Nest.js is a framework designed for building scalable server-side applications. In many ways, Nest is familiar to Angular developers:
- It has excellent TypeScript support.
- Its dependency injection system is similar to the one in Angular.
- It emphasises testability.
- Its configuration APIs are similar to Angular as well.
Many conventions and best practices used in Angular applications can be also be used in Nest.
Setting Up @nx/nest
Generating a new workspace
To create a new workspace with Nest, run the following command:
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npx create-nx-workspace my-workspace --preset=nest
Yarn users can use the following command instead:
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yarn create nx-workspace my-workspace --preset=nest
Installation
Make sure to install the @nx/nest
version that matches the version of nx
in your repository. If the version numbers get out of sync, you can encounter some difficult to debug errors. You can fix Nx version mismatches with this recipe.
In any Nx workspace, you can install @nx/nest
by running the following command:
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nx add @nx/nest
This will install the correct version of @nx/nest
.
Create Applications
You can add a new Nest application with the following command:
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nx g @nx/nest:app apps/my-nest-app
Application Proxies
Generating Nest applications has an option to configure other projects in the workspace to proxy API requests. This can be done by passing the --frontendProject
with the project name you wish to enable proxy support for.
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nx g @nx/nest:app apps/my-nest-app --frontendProject my-angular-app
Create Libraries
You can add a new Nest library with the following command:
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nx g @nx/nest:lib libs/my-nest-lib
To make the library buildable
, use the following command:
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nx g @nx/nest:lib libs/my-nest-lib --buildable
To make the library publishable
, use the following command:
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nx g @nx/nest:lib libs/my-nest-lib --publishable --importPath=@my-workspace/my-nest-lib
Read more about building and publishing libraries here.
Nest Generators
The Nest plugin for Nx extends the generators provided by Nest. Any commands that can be used with the Nest CLI can also be used with the nx
command. The --project
flag should be used for all Nest generators.
--project
is used to infer the root of the project where the generators will generate the files.
Using Nest
Build
You can build an application with the following command:
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nx build my-nest-app
This applies to buildable
libraries as well
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nx build my-nest-lib
Waiting for other builds
Setting the waitUntilTargets
option with an array of projects (with the following format: "project:target"
) will execute those commands before serving the Nest application.
Serve
You can serve an application with the following command:
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nx serve my-nest-app
The serve
command runs the build
target, and executes the application.
By default, the serve command will run in watch
mode. This allows code to be changed, and the Nest application to be rebuilt automatically.
Debugging
Nest applications also have the inspect
flag set, so you can attach your debugger to the running instance.
Debugging is set to use a random port that is available on the system. The port can be changed by setting the port option in the serve
target in the project.json
. Or by running the serve command with --port <number>
.
For additional information on how to debug Node applications, see the Node.js debugging getting started guide.
Lint
You can lint an application with the following command:
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nx lint my-nest-app
You can lint a library with the following command:
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nx lint my-nest-lib
Unit Test
You can run unit test for an application with the following command:
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nx test my-nest-app
You can run unit test for a library with the following command:
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nx test my-nest-lib
Using CLI Plugins
Nest supports the use of various CLI plugins to enhance the development experience. Plugins can be configured via transformers property in NxWebpackPlugin. As an example, to set up a Swagger plugin, modify the Nest application's Webpack configuration as follows:
1const { NxWebpackPlugin } = require('@nx/webpack');
2
3module.exports = {
4 // ...
5 plugins: [
6 new NxWebpackPlugin({
7 // ...
8 transformers: [
9 {
10 name: '@nestjs/swagger/plugin',
11 options: {
12 dtoFileNameSuffix: ['.dto.ts', '.entity.ts'],
13 },
14 },
15 ],
16 }),
17 ],
18};
19
Deployment
Ensuring a smooth and reliable deployment of a Nest.js application in a production environment requires careful planning and the right strategy. Depending on your specific needs and infrastructure, you can choose from several deployment approaches. Below are four commonly used methods:
Using Docker: Create a Dockerfile that specifies the application's environment and dependencies. Build a Docker image and optionally push it to a container registry. Deploy and run the Docker container on the server. Utilize the
@nx/node:setup-docker
generator to streamline the Docker setup process.Installing Dependencies on the Server: Transfer the build artifacts to the server, install all dependencies using the package manager of your choice, and start the application. Ensure that NxAppWebpackPlugin is configured with
generatePackageJson: true
so that the build artifacts directory includespackage.json
andpackage-lock.json
(or the equivalent files for other package managers).Transferring Pre-installed Dependencies: Install dependencies during the build process, and transfer the build artifacts along with the
node_modules
directory to the server. Typically, the artifacts are archived for faster transfer and then unarchived on the server.Bundling Dependencies: By default, Nx/Nest creates a setup that externalizes all dependencies, meaning they are not included in the bundle. This behavior can be adjusted using the
externalDependencies
parameter in the webpack configuration with NxAppWebpackPlugin. After bundling, transfer the package to the server and start the application.
Bundling dependencies is typically not recommended for Node applications.