test containers blog

_posts/2024-08-20-testcontainers-with-github-actions.markdown

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+---
+layout: post
+title: '[node] Testcontainers with github actions'
+date: 2024-08-20 00:00:00 +0100
+---
+
+I tried running testcontainers on github actions, the trick to running them was increasing the default timeout for your tests.
+Github has out of the box support for docker, there is a delay with startup though, so you need to account for that
+I thought this was a hack, but the official testcontainers repo uses this approach as well.
+
+```json
+{
+  // jest config
+  "testEnvironment": "node",
+  "preset": "ts-jest",
+  "testTimeout": 60000
+}
+```
+
+## About testcontainers
+
+In case you're wondering what testcontainers are; it's a library that provides lightweight containers for your tests.
+It allows you to easily set up dependencies, so you can run your tests against in a "real" environment.
+You can E2E test a CRUD backend with a real database, or test against an actual message queue.
+It adds a lot of reliability since the dependencies are very close to the real deal, and it makes E2E/integration test set up a breeze.
+
+Here's an example test using nestjs with drizzle as an ORM:
+
+```typescript
+import request from 'supertest';
+import { runMigrations } from '@db/migrate';
+import { schema } from '@db/schema';
+import { DrizzlePostgresModule } from '@knaadh/nestjs-drizzle-postgres';
+import { INestApplication } from '@nestjs/common';
+import { PostgreSqlContainer } from '@testcontainers/postgresql';
+import { StartedPostgreSqlContainer } from '@testcontainers/postgresql/build/postgresql-container';
+import { UserModule } from '../src/user/user.module';
+
+describe('users e2e', () => {
+  let app: INestApplication;
+  let postgresContainer: StartedPostgreSqlContainer;
+
+  beforeAll(async () => {
+    postgresContainer = await new PostgreSqlContainer().start();
+
+    // add DATABASE_URL to env so we can use it for our migrations
+    process.env.DATABASE_URL = postgresContainer.getConnectionUri();
+
+    const moduleFixture = await Test.createTestingModule({
+      imports: [
+          DrizzlePostgresModule.registerAsync({
+              tag: 'DB',
+              useFactory() {
+                  return {
+                      postgres: {
+                          url: postgresContainer.getConnectionUri(),
+                      },
+                      config: { schema },
+                  };
+              },
+          }),
+          UserModule
+      ],
+    }).compile();
+
+    // this also runs a seed method for testdata in non dev environments  
+    await runMigrations();
+
+    app = moduleFixture.createNestApplication();
+    await app.init();
+  });
+
+  afterAll(async () => {
+    await app.close();
+    await postgresContainer.stop();
+  });
+
+  it('Get users', () => {
+    // Run actual http request against server with postgres database 
+    return request(app.getHttpServer())
+      .get('/users')
+      .expect(200)
+      .expect([
+        { id: 1, name: 'Marijn' },
+      ]);
+  });
+});
+```