feat: add healthcheck to be used by Dockerfile

src/healthcheck/__tests__/healthcheck.spec.ts

@@ -0,0 +1,54 @@
+import http, { ClientRequest, IncomingMessage } from 'http';
+
+jest.mock('http');
+jest.mock('form-data');
+
+const mockHttp = http as jest.Mocked<typeof http>;
+
+interface KeyValue {
+  [key: string]: (response: IncomingMessage | Error) => void;
+}
+
+describe('healthcheck', () => {
+  const map: KeyValue = {};
+
+  const request = ({
+    on: (key: string, cb: (response: IncomingMessage | Error) => void) => {
+      map[key] = cb;
+    },
+    end: jest.fn()
+  } as unknown) as ClientRequest;
+
+  beforeEach(() => {
+    mockHttp.request.mockImplementationOnce(() => request);
+  });
+
+  it('should exit with error code 1 if an error occurs', () => {
+    const exitSpy = jest.spyOn(process, 'exit').mockImplementation();
+
+    require('../index');
+
+    map['error'](new Error());
+
+    expect(request.end).toHaveBeenCalled();
+    expect(exitSpy).toHaveBeenCalledWith(1);
+  });
+
+  it.each([
+    [1, 404],
+    [1, 422],
+    [1, 500],
+    [0, 200]
+  ])('should exit with error code %s if the response has status code %s', (exitCode, statusCode) => {
+    const exitSpy = jest.spyOn(process, 'exit').mockImplementation();
+
+    require('../index');
+
+    const response = {
+      statusCode
+    } as Partial<IncomingMessage>;
+
+    map['response'](response as IncomingMessage);
+    expect(exitSpy).toHaveBeenCalledWith(exitCode);
+  });
+});

src/healthcheck/index.ts

@@ -0,0 +1,37 @@
+import http from 'http';
+import path from 'path';
+import fs from 'fs';
+import FormData from 'form-data';
+import { info, trace } from '../logger';
+
+const form = new FormData();
+form.append('data', fs.createReadStream(path.resolve('src/healthcheck/rosterFile.rosz')));
+
+const options = {
+  host: 'localhost',
+  port: '8000',
+  path: '/conversion',
+  timeout: 2000,
+  method: 'POST',
+  headers: form.getHeaders()
+};
+
+const request = http.request(options);
+form.pipe(request);
+
+request.on('response', (res) => {
+  info(`HEALTH CHECK STATUS: ${res.statusCode}`);
+  if (res.statusCode == 200) {
+    process.exit(0);
+  } else {
+    process.exit(1);
+  }
+});
+
+request.on('error', function (err) {
+  trace(err);
+  request.end();
+  process.exit(1);
+});
+
+export default {};