Simple Order Api

Simple Order API is a simple rest API created with the excellent NestJs Framework. This API server has only one functional endpoint [post] /api/order which, receives the order's JSON object and saves it in a database.

The purpose of this project is to demonstrate the followings:

• Development of an extensible backend service with TypeScript and NestJs framework.
• Using TypeORM to design data models and insert / query data.
• Application of the SOLID principles:
  • Single Responsibility
  • Open/Closed Principle
  • Liskov Substitution
  • Interface Segregation
  • Dependency Inversion
• Automatic software testing with jest and achieving almost 100% code coverage:
  • Unit Tests
  • End-to-End Tests
• Containerization with Docker and docker-compose
• Using CI/CD tools:
  • Travis CI to automatically run tests, build docker images and push to docker hub.
  • Coveralls to store test coverage reports.
• Usage of Swagger to document the API specifications

Project Structure

• src/ contains all typescript source files
  • dto/ contains data type definitions for api interfaces
  • models/ contains data models and entities
  • services/ contains services required for creating and validating Orders and Products
  • app.module.ts file is the main Nest module and contains the dependency injection configurations
  • order.controller.ts file is the controller class to handler api/order endpoint
  • *.spec.ts files are the unit tests files (for example order.controller.spec.ts)
• test/ directory contains e2e tests

Extensibility vs Simplicity

According to the KISS Principle (Keep It Stupid Simple), the complexity of this project seems too high for now. But there is a consideration for support new product and order types in the future with minimum changes:

1. Define new Product and Order types in the dto/ and models/ directories.
2. Implement their associated handlers in the services/ folder.
3. Register new handlers in the app.module.ts file.

Online Resources

• The project's Swagger documentation is under http://localhost:3000/docs path
• Docker Hub page containing the docker images
• Travis CI page to show test results and build status
• Coveralls page to show test coverage results

Requirements

• node.js
• yarn
• postgres databases:
  • simple_order for development
  • simple_order_test for e2e tests

Installation

$ yarn install

Running the app

# development
$ yarn start

# watch mode
$ yarn start:dev

# production build 
$ yarn build

# production mode
$ yarn start:prod

Test

# run all tests and calculate the coverage
$ yarn test

# unit tests only
$ yarn test:unit

# e2e tests only
$ yarn test:e2e

Deployment

$ docker-compose up 

Stay in touch

• Author: Emech En < [email protected] >