chore: Extract authentication logic of the apps to their own classes

packages/backend/src/apps/postgresql/authentication.ts

@@ -0,0 +1,38 @@
+import { Client } from 'pg';
+import App from '../../models/app';
+
+export default class Authentication {
+  client: any
+  connectionData: any
+  appData: any
+
+  constructor(connectionData: any) {
+    this.client = new Client({
+      host: connectionData.host,
+      port: connectionData.port,
+      database: connectionData.database,
+      user: connectionData.username,
+      password: connectionData.password,
+    })
+
+    this.connectionData = connectionData;
+    this.appData = App.findOneByKey('postgresql');
+  }
+
+  async verifyCredentials() {
+    await this.client.connect()
+
+    return {
+      screenName: this.connectionData.database
+    }
+  }
+
+  async isStillVerified() {
+    try {
+      await this.client.connect()
+      return true;
+    } catch(error) {
+      return false
+    }
+  }
+}

packages/backend/src/apps/postgresql/index.ts

@@ -1,38 +1,9 @@
-import { Client } from 'pg';
-import App from '../../models/app';
+import Authentication from './authentication'
 
 export default class PostgreSQL {
-  client: any
-  connectionData: any
-  appData: any
+  authenticationClient: any;
 
   constructor(connectionData: any) {
-    this.client = new Client({
-      host: connectionData.host,
-      port: connectionData.port,
-      database: connectionData.database,
-      user: connectionData.username,
-      password: connectionData.password,
-    })
-
-    this.connectionData = connectionData;
-    this.appData = App.findOneByKey('postgresql');
-  }
-
-  async verifyCredentials() {
-    await this.client.connect()
-
-    return {
-      screenName: this.connectionData.database
-    }
-  }
-
-  async isStillVerified() {
-    try {
-      await this.client.connect()
-      return true;
-    } catch(error) {
-      return false
-    }
+    this.authenticationClient = new Authentication(connectionData);
   }
 }