ts-generate-schema

Generate json-schema files from your typescript definitions

Features

• Generate json-schema files from one single command :

  • Run npx ts-generate-schema src/**/*-response.dto.ts in your root folder.
  • After writing the following TypeScript definition :

    src/types/login-user-response.dto.ts

  export type LoginUserResponseDTO = {
    user: {
      id: string;
      email: string;
      username: string;
      firstname: string;
    };
    token: {
      expiresIn: number;
      accessToken: string;
    };
  };

  • Get this file in return :

  src/types/schema/login-user-response-dto.jsc.ts

  export default {
    type: 'object',
    properties: {
      user: {
        type: 'object',
        properties: {
          id: {
            type: 'string',
          },
          email: {
            type: 'string',
          },
          username: {
            type: 'string',
          },
          firstname: {
            type: 'string',
          },
        },
        required: ['email', 'firstname', 'id', 'username'],
      },
      token: {
        type: 'object',
        properties: {
          expiresIn: {
            type: 'number',
          },
          accessToken: {
            type: 'string',
          },
        },
        required: ['accessToken', 'expiresIn'],
      },
    },
    required: ['token', 'user'],
    $schema: 'http://json-schema.org/draft-07/schema#',
  };

Usage

• Install with npm i -D ts-generate-schema or yarn add -D ts-generate-schema
• Add the following scripts in your package.json.

"schema": "ts-generate-schema <pattern>"

• You can also use it globally:
  • With npm i -g ts-generate-schema and simply running ts-generate-schema <pattern> anywhere
  • with npx, npx ts-generate-schema <pattern>

Command Line

<pattern> is a glob pattern to find files to handle.

I would recommand giving those files a special extension (such as -response.dto.ts for request) and use ts-generate-schema src/**/*-response.dto.ts

Usage: ts-generate-schema <pattern>
Options:
  --help     Show help                                                 [boolean]
  --version  Show version number                                       [boolean]
  --to       Extension of generated json-schema     [string] [default: "jsc.ts"]
  --export   How to export generated json-schema from file
                                            [string] [default: "export default"]
  --out       Path to the generated schema directory     [string] [default: "schema"]

Motivation

I'm passionate about software architecture, quality and scaling.

I've recently been working on a web and mobile project where I made tons of API calls. I came to the conlusion that my way of handling API calls was ... not good enough.

And, at some point in every project I worked on, we had a server getting an update without the front-end team being perfectly notified about it.

My aim was to be able to know when a request we received was different from our primary API. As I'm a TypeScript lover and user, I quickly found some way to use TS definitions as json-schemas with a validator such as AJV.

Nevertheless, libraries providing us with TypeScript to JSON Schema functionalities were too low level to be used as they are.

I had axios and interceptors to setup my strategies, AJV to handle validation and now this library to quickly generate my JSON-schemas from my TypeScript definitions.

License

MIT