feat: Replace express with native http module

* refactor: replace express with native http module

* fix: 404 when unhandled

* chore: removed express dependency

* chore: updated package-lock.json

* docs: added documentation for BaseHttpServerFactory

* chore: updated package-lock.json

Co-authored-by: Arthur Joppart <arthur@digita.ai>

test/unit/server/BaseHttpServerFactory.test.ts

@@ -0,0 +1,68 @@
+import type { Server } from 'http';
+import request from 'supertest';
+import { BaseHttpServerFactory } from '../../../src/server/BaseHttpServerFactory';
+import type { HttpHandler } from '../../../src/server/HttpHandler';
+import type { HttpResponse } from '../../../src/server/HttpResponse';
+
+const handler: jest.Mocked<HttpHandler> = {
+  handleSafe: jest.fn(async(input: { response: HttpResponse }): Promise<void> => {
+    input.response.writeHead(200);
+    input.response.end();
+  }),
+} as any;
+
+describe('BaseHttpServerFactory', (): void => {
+  let server: Server;
+
+  beforeAll(async(): Promise<void> => {
+    const factory = new BaseHttpServerFactory(handler);
+    server = factory.startServer(5555);
+  });
+
+  afterAll(async(): Promise<void> => {
+    server.close();
+  });
+
+  it('sends incoming requests to the handler.', async(): Promise<void> => {
+    await request(server).get('/').set('Host', 'test.com').expect(200);
+
+    expect(handler.handleSafe).toHaveBeenCalledTimes(1);
+    expect(handler.handleSafe).toHaveBeenLastCalledWith({
+      request: expect.objectContaining({
+        headers: expect.objectContaining({ host: 'test.com' }),
+      }),
+      response: expect.objectContaining({}),
+    });
+  });
+
+  it('returns a 404 when the handler does not do anything.', async(): Promise<void> => {
+    handler.handleSafe.mockResolvedValueOnce(undefined);
+
+    await expect(request(server).get('/').expect(404)).resolves.toBeDefined();
+  });
+
+  it('writes an error to the HTTP response.', async(): Promise<void> => {
+    handler.handleSafe.mockRejectedValueOnce(new Error('dummyError'));
+
+    const res = await request(server).get('/').expect(500);
+    expect(res.headers['content-type']).toBe('text/plain; charset=utf-8');
+    expect(res.text).toContain('dummyError');
+  });
+
+  it('does not write an error if the response had been started.', async(): Promise<void> => {
+    handler.handleSafe.mockImplementationOnce(async(input: { response: HttpResponse }): Promise<void> => {
+      input.response.write('content');
+      throw new Error('dummyError');
+    });
+
+    const res = await request(server).get('/');
+    expect(res.text).not.toContain('dummyError');
+  });
+
+  it('throws unknown errors if its handler throw non-Error objects.', async(): Promise<void> => {
+    handler.handleSafe.mockRejectedValueOnce('apple');
+
+    const res = await request(server).get('/').expect(500);
+    expect(res.text).toContain('Unknown error.');
+  });
+});