Added db connection test to health check

package.json

@@ -186,6 +186,7 @@
     "test:bootstrap": "NODE_ENV=test mocha ./test/pre-test-scripts.ts  ./src/server/bootstrap.test.ts",
     "test:utils": "NODE_ENV=test mocha ./src/utils/utils.test.ts",
     "test:inverterScript": "NODE_ENV=test mocha ./test/pre-test-scripts.ts ./src/scripts/syncDataWithInverter.test.ts",
+    "test:healthCheck": "NODE_ENV=test mocha ./test/pre-test-scripts.ts ./src/server/bootstrap.test.ts",
     "start": "NODE_ENV=development ts-node-dev --project ./tsconfig.json --respawn ./src/index.ts",
     "start:test": "NODE_ENV=development ts-node-dev --project ./tsconfig.json --respawn ./test.ts",
     "serve": "pm2 startOrRestart ecosystem.config.js --node-args='--max-old-space-size=8192'",

src/server/bootstrap.test.ts

@@ -6,6 +6,6 @@ describe('health check test case', healthCheckTestCases);
 function healthCheckTestCases() {
   it('should return empty array for now startTimestamp', async () => {
     const result = await axios.get('http://localhost:4000/health');
-    assert.equal(result.data, 'Hi every thing seems ok');
+    assert.equal(result.data, 'OK');
   });
 }

src/server/bootstrap.ts

@@ -7,7 +7,7 @@ import { ApolloServer } from '@apollo/server';
 import { expressMiddleware } from '@apollo/server/express4';
 import { ApolloServerPluginSchemaReporting } from '@apollo/server/plugin/schemaReporting';
 import { ApolloServerPluginLandingPageGraphQLPlayground } from '@apollo/server-plugin-landing-page-graphql-playground';
-import express, { json, Request } from 'express';
+import express, { json, Request, RequestHandler } from 'express';
 import { Container } from 'typedi';
 import { Resource } from '@adminjs/typeorm';
 import { validate } from 'class-validator';
@@ -424,9 +424,7 @@ export async function bootstrap() {
       bodyParser.raw({ type: 'application/json' }),
       handleStripeWebhook,
     );
-    app.get('/health', (_req, res) => {
-      res.send('Hi every thing seems ok');
-    });
+    app.get('/health', healthCheck);
     app.post('/transak_webhook', webhookHandler);
 
     const httpServer = http.createServer(app);
@@ -472,3 +470,13 @@ async function setPgTrgmParameters(ds: DataSource) {
     `SET pg_trgm.word_similarity_threshold TO ${similarityThreshold};`,
   );
 }
+
+const healthCheck: RequestHandler = async (_req, res) => {
+  const ds = AppDataSource.getDataSource();
+  const result = (await ds.query('select version()')) || [];
+  const version = result[0]?.version || '';
+  if (!version.startsWith('PostgreSQL')) {
+    throw new Error('Unexpected db result');
+  }
+  res.sendStatus(200);
+};