fix build error in job launcher server

packages/apps/job-launcher/server/src/common/constants/errors.ts

@@ -171,3 +171,10 @@ export enum ErrorQualification {
   FailedToFetchQualifications = 'Failed to fetch qualifications',
   InvalidQualification = `Invalid qualification`,
 }
+
+/**
+ * Represents error messages associated with encryption.
+ */
+export enum ErrorEncryption {
+  MissingPrivateKey = 'Encryption private key cannot be empty, when it is enabled',
+}

packages/apps/job-launcher/server/src/modules/encryption/encryption.module.ts

@@ -2,16 +2,20 @@ import { Module, Global, Provider } from '@nestjs/common';
 import { Encryption } from '@human-protocol/sdk';
 import { ConfigModule } from '@nestjs/config';
 import { PGPConfigService } from '../../common/config/pgp-config.service';
+import { ErrorEncryption } from '../../common/constants/errors';
 
 const encryptionProvider: Provider = {
   provide: Encryption,
   useFactory: async (pgpConfigService: PGPConfigService) => {
-    if (!pgpConfigService.encrypt) {
+    if (!pgpConfigService.encrypt && !pgpConfigService.privateKey) {
       return null;
     }
     const privateKey = pgpConfigService.privateKey;
     const passPhrase = pgpConfigService.passphrase;
-    return await Encryption.build(privateKey, passPhrase);
+
+    if (privateKey) return await Encryption.build(privateKey, passPhrase);
+
+    throw new Error(ErrorEncryption.MissingPrivateKey);
   },
   inject: [PGPConfigService],
 };