Run database setup and teardown via suite

Manually calling the DB setup / teardown within a test was verbose, but
more importantly it meant teardown wouldn't happen if a test failed.
That's no good!

By using Jest's suite functionality we ensure that setup and teardown
both run for each test regardless of test outcome.

Issue #43 Support integration tests

package.json

@@ -12,8 +12,8 @@
     "migrate": "node -r dotenv/config dist/scripts/migrate.js",
     "migrate:dev": "ts-node -r dotenv/config src/scripts/migrate.ts | pino-pretty",
     "test": "npm run test:unit && npm run test:integration",
-    "test:unit": "jest --config=jest.config.unit.js | pino-pretty",
-    "test:integration": "jest --config=jest.config.int.js --runInBand | pino-pretty",
+    "test:unit": "jest --config=jest.config.unit.js",
+    "test:integration": "jest --config=jest.config.int.js --runInBan",
     "start": "node dist/index.js",
     "start:dev": "ts-node src/index.ts | pino-pretty"
   },

src/__tests__/canonicalFields.int.test.ts

@@ -1,20 +1,14 @@
 import request from 'supertest';
 import { app } from '../app';
-import {
-  prepareDatabaseForCurrentWorker,
-  cleanupDatabaseForCurrentWorker,
-} from '../test/harnessFunctions';
 
 const agent = request.agent(app);
 
 describe('/canonicalFields', () => {
   describe('/', () => {
     it('should return HTTP Status Code 200 OK', async () => {
-      await prepareDatabaseForCurrentWorker();
       await agent
         .get('/canonicalFields')
         .expect(200);
-      await cleanupDatabaseForCurrentWorker();
     });
   });
 });

src/test/integrationSuiteSetup.ts

@@ -3,7 +3,19 @@
  * via `setupFilesAfterEnv`.
  */
 import { db } from '../database';
+import {
+  prepareDatabaseForCurrentWorker,
+  cleanupDatabaseForCurrentWorker,
+} from './harnessFunctions'
 
 afterAll(async () => {
   await db.close();
 });
+
+beforeEach(async () => {
+  await prepareDatabaseForCurrentWorker();
+})
+
+afterEach(async () => {
+  await cleanupDatabaseForCurrentWorker();
+})