Backend-generator

A simple script to create a structured backend using layered architecture, in addition to the automatic creation of CRUD's based on pre-defined models.

The generated backend will use the postgres database, in addition to using express, and schema validations with joi. The use of the Prisma library is optional.

Backend-generator was created in order to facilitate the creation of new projects using NodeJs and following good practices.

As we develop our projects, some tasks may be repetitive:

• Structuring project folders;
• Creation of CRUD's for our database tables;
• Validation of data passing using middlewares;
• Between others...

These tasks become boring and end up taking a lot of time.

This library was developed to mitigate these problems. Through it, we were able to have a faster start to development, in addition to helping beginners developers to walk a path of good practices related to the architecture of a server.

Backend-generator will allow your development team to focus on business rules, not repetitive tasks.

Installation

Either through cloning with git or by using npm (the recommended way):

npm install -g backend-generator

And backend-generator will be installed globally to your system path.

You can also install backend-generator as a development dependency:

npm install -D backend-generator 

With a local installation, backend-generator will not be available in your system path or you can't use it directly from the command line. Instead, the local installation of backend-generator can be run by calling it from within an npm script (such as npm start) or using npx backend-generator.

Usage

backend-generator is a cli library, so just run the command to start the application.

backend-generator

This will launch the library displaying a series of options for you to choose and generate your project.

1 - First you must inform a path to the file that defines the models (tables) of your application. We'll talk about this file later.

"Enter the path to read the models.json file: "

2 - After that, you must inform a folder where your project will be saved:

"Enter the path to the folder where the project will be saved. The name of the last folder in the path indicates the name of the project. Ex: ./../my-project "

3 - Select the language you want to use. You can choose between Javascript and Typescript.

"Select a programming language to use in this project: "

4 - Choose if you want to use the Prisma library for migrations and database management:

"Do you want to use prism for better management of your db's migrations ?"

5 - Choose if you want to initialize the package.json in the destination folder of your project:

"Do you want to initialize package.json in the project's destination folder? Choose 'no' if a package.json already exists in the destination folder."

6 - Choose if you want to install the dependencies of your new project after creating the folders and files:

"Do you want to install the dependencies after the project is created ?"

This is enough to generate a new project in the destination folder specified in step 2 of this tutorial. Just run npm start in that folder and your newest server will be online. You can test dynamically generated CRUD routes by accessing http://localhost:[PORT]/MODEL/ using the GET, POST, PUT, DELETE methods.

Please note that some Typescript type errors may be generated if you chose that language.

Models.json what is this ?

The models.json file (not necessarily this name) serves to indicate the format of our database tables, in addition to informing the backend-generator which validations it needs to implement with the Joi library.

{
  "modelName": {
    "columnName": "Joi validations",
    "anotherColumn": "More Joi validations",
    ...
  }
}

Example

Let's create a news blog using the backend-generator library.

Our project will be very simple, it will have Users, Posts and Comments. Users make Posts, and Users can also make comments.

1 - Install the library globally:

npm install -g backend-generator

2 - Create a models.json file to store information from our tables:

{
  "user": {
    "name": ".string().required()",
    "email": ".string().email().required()",
    "password": ".string().required()"
  },
  "post": {
    "title": ".string().required()",
    "content": ".string().required()",
    "authorId": ".number().required()"
  },
  "comment": {
    "content": ".string().required()",
    "authorId": ".number().required()"
  }
}

3 - Run the library to start the cli:

backend-generator

4 - Enter the path to the models.json file you just created:

"Enter the path to read the models.json file: "

5 - Enter a folder where the project will be saved:

"Enter the path to the folder where the project will be saved. The name of the last folder in the path indicates the name of the project. Ex: ./../my-project "

6 - Select the Javascript language for this example.

"Select a programming language to use in this project: "

7 - Choose no to the Prisma library option for this example:

"Do you want to use prism for better management of your db's migrations ?"

8 - Choose yes to initialize the package.json in the destination folder of your project:

"Do you want to initialize package.json in the project's destination folder? Choose 'no' if a package.json already exists in the destination folder."

9 - Choose yes to install the dependencies of your new project after creating the folders and files:

"Do you want to install the dependencies after the project is created ?"

10 - That's it! The project was created in the folder you specified as the destination, and the project's dependencies are already installed. You can test the following routes:

• GET /users
• GET /users/:userId
• POST /users
• PUT /users/:userId
• DELETE /users/:userId

• GET /posts
• GET /posts/:postId
• POST /posts
• PUT /posts/:postId
• DELETE /posts/:postId

• GET /comments
• GET /comments/:commentId
• POST /comments
• PUT /comments/:commentId
• DELETE /comments/:commentId

Just remember that the creation and update routes (POST and PUT) expect to receive a body with the fields informed in our models.json and defined as ".required()".

{
  "user": {
    "name": ".string().required()",
    "email": ".string().email().required()",
    "password": ".string().required()"
  },
  "post": {
    "title": ".string().required()",
    "content": ".string().required()",
    "authorId": ".number().required()"
  },
  "comment": {
    "content": ".string().required()",
    "authorId": ".number().required()"
  }
}

Considerations

Backend-generator is far from reaching its full potential. There are still many bugs to be fixed, features and improvements to be implemented.

This little lib was created in a few hours and is in constant development and improvement process (when the dev has some time '-'). Feel free to contribute to this project.

License

Licensed under the MIT License, Copyright © 2022-present Alex Souza.

See LICENSE for more information.