README.md

Hexagonal Architecture using Express

Note: This is a basic example to demonstrate ArchUnitTS capabilities. Real-world hexagonal architecture applications may have more complex architectural patterns and requirements.

This example demonstrates enforcing ports and adapters pattern, core isolation, and dependency inversion in Express applications using ArchUnitTS.

import { projectFiles, projectSlices, metrics } from 'archunit';

describe('Express Hexagonal Architecture Rules', () => {
  it('core should not depend on adapters', async () => {
    const rule = projectFiles()
      .inFolder('src/core/**')
      .shouldNot()
      .dependOnFiles()
      .inFolder('src/adapters/**');
    await expect(rule).toPassAsync();
  });

  it('core should not depend on infrastructure', async () => {
    const rule = projectFiles()
      .inFolder('src/core/**')
      .shouldNot()
      .dependOnFiles()
      .inFolder('src/infrastructure/**');
    await expect(rule).toPassAsync();
  });

  it('adapters should implement ports', async () => {
    const rule = projectFiles()
      .inFolder('src/adapters/**')
      .should()
      .dependOnFiles()
      .inFolder('src/ports/**');
    await expect(rule).toPassAsync();
  });

  it('should maintain focused business logic', async () => {
    const rule = metrics()
      .inFolder('src/core/**')
      .count()
      .methodCount()
      .shouldBeBelow(12);
    await expect(rule).toPassAsync();
  });

  it('ports should be simple interfaces', async () => {
    const rule = metrics()
      .inFolder('src/ports/**')
      .count()
      .linesOfCode()
      .shouldBeBelow(100);
    await expect(rule).toPassAsync();
  });

  it('adapters should have good cohesion', async () => {
    const rule = metrics()
      .inFolder('src/adapters/**')
      .lcom()
      .lcom96b()
      .shouldBeBelow(0.6);
    await expect(rule).toPassAsync();
  });
});