Initial commit

express/models/db.js

@@ -0,0 +1,65 @@
+const { Pool, Client } = require('pg')
+const debug = require('debug')('termPortal:models/db')
+
+const pool = new Pool()
+
+pool.on('error', (err, client) => {
+  debug('Error on DB pool idle client:')
+  debug({ err, client })
+})
+
+exports.query = (text, params) => pool.query(text, params)
+
+exports.getClient = () => pool.connect()
+
+// Returns a new client from outside the pool.
+exports.getExtraClient = () => {
+  const client = new Client()
+  client.connect()
+  return client
+}
+
+exports.transaction = async queriesFn => {
+  const client = await pool.connect()
+  try {
+    await client.query('BEGIN')
+    await queriesFn(client)
+    await client.query('COMMIT')
+  } catch (error) {
+    await client.query('ROLLBACK')
+    throw error
+  } finally {
+    client.release()
+  }
+}
+
+exports.genParamStr = paramArr => {
+  const paramPlaceholderString = paramArr.reduce((str, param, index) => {
+    if (index) str += ', '
+    str += `$${index + 1}`
+
+    return str
+  }, '')
+
+  return paramPlaceholderString
+}
+
+exports.waitForConnection = () => {
+  return new Promise(resolve => {
+    async function testConnection() {
+      try {
+        // eslint-disable-next-line no-console
+        console.log('Verifying connection to DB server')
+        await pool.query('SELECT 1')
+        // eslint-disable-next-line no-console
+        console.log('Connection to DB server verified')
+        resolve()
+      } catch {
+        // eslint-disable-next-line no-console
+        console.error('Could not connect to DB server')
+        setTimeout(testConnection, 1000)
+      }
+    }
+    testConnection()
+  })
+}