Express.js JSON schema server middleware

Middleware for describing and validating your REST API routes using JSON schemas.

Automatic validation of both inputs and outputs using JSON schema.
Self-descriptive, includes automatic endpoints for all route descriptors.
Includes extensive example showing how to organize your code, perform authentication and use databases.
The route descriptors can be used to generate automatic documentation, testing user interface, TypeScript definitions etc.
Written in TypeScript.
Minimum boilerplate.
Every endpoint handler is in a separate file.
Easy to test with supertest.

Installation

This package is distributed via npm

npm install express-schema-server

Commands

npm run build to build the production version.
npm run test to run tests.
npm run lint to lint the codebase.
npm run start to start the example application.
npm run debug to start the example application in debug mode (--inspect).
npm run coverage to gather code coverage.
npm run prettier to run prettier.

Example

See src/example directory for a full working example code and run npm start to try it out for yourself.

Following is an example route for creating a new user.

import { normalizeType } from "normalize-type";
import { buildResponseSchema, ICustomValidator, IRouteDefinition, JSONSchema4, validateJsonSchema } from "../../../";
import { IServerContext } from "../../app";
import validateUniqueEmail from "../../validators/validateUniqueEmail";
import { IUser, transformUser, userSchema } from "./users";

export interface CreateUserRequest {
  name: string;
  email: string;
}

export const requestSchema: JSONSchema4 = {
  title: "Create user",
  description: "Create a new user account",
  type: "object",
  properties: {
    name: {
      type: "string",
      title: "Name",
      description: "User name",
      minLength: 3,
      maxLength: 100,
    },
    email: {
      type: "string",
      title: "Email",
      description: "Email address",
      minLength: 3,
      maxLength: 256,
      allOf: [
        {
          format: "email",
        },
        {
          format: "unique-email",
        },
      ],
    },
  },
  required: ["name", "email"],
};

export const responseSchema: JSONSchema4 = buildResponseSchema(userSchema);

export default (): IRouteDefinition<IServerContext> => ({
  path: "",
  method: "post",
  metadata: {
    title: "Register user",
    description: "Register a new user account",
    sinceVersion: "1.0.0",
    isDeprecated: false,
  },
  requestSchema,
  responseSchema,
  handler: async (request, response, _next) => {
    const requestData = normalizeType<CreateUserRequest>(request.body);
    const validators: ICustomValidator[] = [validateUniqueEmail(request.db.user)];
    const validationResult = await validateJsonSchema(requestData, requestSchema, validators);

    if (!validationResult.isValid) {
      response.fail(validationResult.errors, responseSchema, validators);

      return;
    }

    const user = await request.db.user.save(requestData);

    response.success<IUser>(transformUser(user), responseSchema, validators);
  },
});

kallaspriit/express-schema-server

Express.js JSON schema server middleware

Installation

Commands

Example