code-flexing · Gezziy · May 30, 2026
diff --git a/harvest-finance/backend/src/insurance/insurance.service.ts b/harvest-finance/backend/src/insurance/insurance.service.ts
@@ -16,7 +16,7 @@ import {
 } from '../database/entities/insurance-subscription.entity';
 import { FarmVault } from '../database/entities/farm-vault.entity';
 import { NotificationsService } from '../notifications/notifications.service';
-import { NotificationType } from '../database/entities/notification.entity';
+import { NotificationHelper } from '../notifications/notification.helper';
 import { RiskAssessmentDto, SubscribeInsuranceDto } from './dto/insurance.dto';
 
 /** ---------- Types returned to controllers ---------- */
@@ -283,13 +283,15 @@ export class InsuranceService {
 
     const saved = await this.subscriptionRepo.save(subscription);
 
-    // Notify the farmer
-    await this.notificationsService.create({
-      userId,
-      title: 'Insurance Plan Activated',
-      message: `Your "${plan.name}" crop insurance is now active. Monthly premium: $${monthlyPremium.toFixed(2)}. Coverage period: ${coverageStart.toLocaleDateString()} – ${coverageEnd.toLocaleDateString()}.`,
-      type: NotificationType.INSURANCE,
-    });
+    await this.notificationsService.create(
+      NotificationHelper.insuranceActivated({
+        userId,
+        planName: plan.name,
+        monthlyPremium,
+        coverageStart,
+        coverageEnd,
+      }),
+    );
 
     return saved;
   }
@@ -326,12 +328,14 @@ export class InsuranceService {
       .getMany();
 
     for (const sub of expiring) {
-      await this.notificationsService.create({
-        userId: sub.userId,
-        title: 'Insurance Renewal Reminder',
-        message: `Your "${sub.plan.name}" insurance coverage expires on ${new Date(sub.coverageEnd).toLocaleDateString()}. Renew now to maintain protection for your ${sub.cropType} crop.`,
-        type: NotificationType.INSURANCE,
-      });
+      await this.notificationsService.create(
+        NotificationHelper.insuranceRenewalReminder({
+          userId: sub.userId,
+          planName: sub.plan.name,
+          coverageEnd: sub.coverageEnd,
+          cropType: sub.cropType,
+        }),
+      );
     }
 
     return expiring.length;

diff --git a/harvest-finance/backend/src/notifications/notification.helper.spec.ts b/harvest-finance/backend/src/notifications/notification.helper.spec.ts
@@ -0,0 +1,87 @@
+import { NotificationType } from '../database/entities/notification.entity';
+import { NotificationHelper } from './notification.helper';
+
+describe('NotificationHelper', () => {
+  it('builds large deposit admin alerts', () => {
+    expect(
+      NotificationHelper.largeDepositAlert({
+        amount: 12000,
+        vaultName: 'Maize Vault',
+      }),
+    ).toEqual({
+      title: 'Large Deposit Alert',
+      message:
+        'A large deposit of 12000 has been initiated for vault Maize Vault.',
+      type: NotificationType.LARGE_TRANSACTION,
+      adminOnly: true,
+    });
+  });
+
+  it('builds user deposit confirmation notifications', () => {
+    expect(
+      NotificationHelper.depositConfirmed({
+        userId: 'user-1',
+        amount: '500.25',
+        vaultId: 'vault-1',
+      }),
+    ).toEqual({
+      userId: 'user-1',
+      title: 'Deposit Confirmed',
+      message: 'Your deposit of 500.25 into vault vault-1 has been confirmed.',
+      type: NotificationType.DEPOSIT,
+    });
+  });
+
+  it('builds user withdrawal confirmation notifications', () => {
+    expect(
+      NotificationHelper.withdrawalConfirmed({
+        userId: 'user-1',
+        amount: 250,
+        vaultName: 'Cassava Vault',
+      }),
+    ).toEqual({
+      userId: 'user-1',
+      title: 'Withdrawal Confirmed',
+      message:
+        'Your withdrawal of 250 from vault Cassava Vault has been confirmed.',
+      type: NotificationType.WITHDRAWAL,
+    });
+  });
+
+  it('builds insurance activation notifications', () => {
+    const coverageStart = new Date('2026-01-01T00:00:00.000Z');
+    const coverageEnd = new Date('2026-12-31T00:00:00.000Z');
+
+    expect(
+      NotificationHelper.insuranceActivated({
+        userId: 'user-1',
+        planName: 'Basic Cover',
+        monthlyPremium: 18.5,
+        coverageStart,
+        coverageEnd,
+      }),
+    ).toEqual({
+      userId: 'user-1',
+      title: 'Insurance Plan Activated',
+      message: `Your "Basic Cover" crop insurance is now active. Monthly premium: $18.50. Coverage period: ${coverageStart.toLocaleDateString()} - ${coverageEnd.toLocaleDateString()}.`,
+      type: NotificationType.INSURANCE,
+    });
+  });
+
+  it('builds reward claim notifications', () => {
+    expect(
+      NotificationHelper.rewardsClaimed({
+        userId: 'user-1',
+        claimedAmount: 1.234567891,
+        vaultId: 'vault-1',
+        vaultName: 'Rice Vault',
+      }),
+    ).toEqual({
+      userId: 'user-1',
+      title: 'Rewards Claimed',
+      message:
+        'You have successfully claimed 1.23456789 in rewards from vault Rice Vault.',
+      type: NotificationType.REWARD,
+    });
+  });
+});
diff --git a/harvest-finance/backend/src/notifications/notification.helper.ts b/harvest-finance/backend/src/notifications/notification.helper.ts
@@ -0,0 +1,111 @@
+import { NotificationType } from '../database/entities/notification.entity';
+import { CreateNotificationDto } from './dto/create-notification.dto';
+
+export interface LargeDepositNotificationParams {
+  amount: number;
+  vaultName: string;
+}
+
+export interface DepositConfirmedNotificationParams {
+  userId: string;
+  amount: number | string;
+  vaultId: string;
+}
+
+export interface WithdrawalConfirmedNotificationParams {
+  userId: string;
+  amount: number;
+  vaultName: string;
+}
+
+export interface InsuranceActivatedNotificationParams {
+  userId: string;
+  planName: string;
+  monthlyPremium: number;
+  coverageStart: Date;
+  coverageEnd: Date;
+}
+
+export interface InsuranceRenewalNotificationParams {
+  userId: string;
+  planName: string;
+  coverageEnd: Date | string;
+  cropType: string;
+}
+
+export interface RewardsClaimedNotificationParams {
+  userId: string;
+  claimedAmount: number;
+  vaultId?: string;
+  vaultName: string;
+}
+
+export class NotificationHelper {
+  static largeDepositAlert(
+    params: LargeDepositNotificationParams,
+  ): CreateNotificationDto {
+    return {
+      title: 'Large Deposit Alert',
+      message: `A large deposit of ${params.amount} has been initiated for vault ${params.vaultName}.`,
+      type: NotificationType.LARGE_TRANSACTION,
+      adminOnly: true,
+    };
+  }
+
+  static depositConfirmed(
+    params: DepositConfirmedNotificationParams,
+  ): CreateNotificationDto {
+    return {
+      userId: params.userId,
+      title: 'Deposit Confirmed',
+      message: `Your deposit of ${params.amount} into vault ${params.vaultId} has been confirmed.`,
+      type: NotificationType.DEPOSIT,
+    };
+  }
+
+  static withdrawalConfirmed(
+    params: WithdrawalConfirmedNotificationParams,
+  ): CreateNotificationDto {
+    return {
+      userId: params.userId,
+      title: 'Withdrawal Confirmed',
+      message: `Your withdrawal of ${params.amount} from vault ${params.vaultName} has been confirmed.`,
+      type: NotificationType.WITHDRAWAL,
+    };
+  }
+
+  static insuranceActivated(
+    params: InsuranceActivatedNotificationParams,
+  ): CreateNotificationDto {
+    return {
+      userId: params.userId,
+      title: 'Insurance Plan Activated',
+      message: `Your "${params.planName}" crop insurance is now active. Monthly premium: $${params.monthlyPremium.toFixed(2)}. Coverage period: ${params.coverageStart.toLocaleDateString()} - ${params.coverageEnd.toLocaleDateString()}.`,
+      type: NotificationType.INSURANCE,
+    };
+  }
+
+  static insuranceRenewalReminder(
+    params: InsuranceRenewalNotificationParams,
+  ): CreateNotificationDto {
+    return {
+      userId: params.userId,
+      title: 'Insurance Renewal Reminder',
+      message: `Your "${params.planName}" insurance coverage expires on ${new Date(params.coverageEnd).toLocaleDateString()}. Renew now to maintain protection for your ${params.cropType} crop.`,
+      type: NotificationType.INSURANCE,
+    };
+  }
+
+  static rewardsClaimed(
+    params: RewardsClaimedNotificationParams,
+  ): CreateNotificationDto {
+    const source = params.vaultId ? `vault ${params.vaultName}` : 'all vaults';
+
+    return {
+      userId: params.userId,
+      title: 'Rewards Claimed',
+      message: `You have successfully claimed ${params.claimedAmount.toFixed(8)} in rewards from ${source}.`,
+      type: NotificationType.REWARD,
+    };
+  }
+}
diff --git a/harvest-finance/backend/src/notifications/notifications.service.ts b/harvest-finance/backend/src/notifications/notifications.service.ts
@@ -1,10 +1,7 @@
 import { Injectable, NotFoundException } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
-import {
-  Notification,
-  NotificationType,
-} from '../database/entities/notification.entity';
+import { Notification } from '../database/entities/notification.entity';
 import { CreateNotificationDto } from './dto/create-notification.dto';
 import { NotificationResponseDto } from './dto/notification-response.dto';
 

diff --git a/harvest-finance/backend/src/rewards/rewards.service.ts b/harvest-finance/backend/src/rewards/rewards.service.ts
@@ -11,7 +11,7 @@ import {
   ClaimRewardsResponseDto,
 } from './dto/reward-response.dto';
 import { NotificationsService } from '../notifications/notifications.service';
-import { NotificationType } from '../database/entities/notification.entity';
+import { NotificationHelper } from '../notifications/notification.helper';
 import { VaultGateway } from '../realtime/vault.gateway';
 
 @Injectable()
@@ -113,13 +113,14 @@ export class RewardsService {
     });
     await this.rewardRepo.save(claimRecord);
 
-    // Trigger notification for user
-    await this.notificationsService.create({
-      userId,
-      title: 'Rewards Claimed',
-      message: `You have successfully claimed ${claimedAmount.toFixed(8)} in rewards from ${vaultId ? 'vault ' + vaultName : 'all vaults'}.`,
-      type: NotificationType.REWARD,
-    });
+    await this.notificationsService.create(
+      NotificationHelper.rewardsClaimed({
+        userId,
+        claimedAmount,
+        vaultId,
+        vaultName,
+      }),
+    );
 
     // Emit real-time event
     this.vaultGateway.emitHarvest({

diff --git a/harvest-finance/backend/src/vaults/vaults.service.ts b/harvest-finance/backend/src/vaults/vaults.service.ts
@@ -18,7 +18,7 @@ import {
   DepositResponseDto,
 } from './dto/vault-response.dto';
 import { NotificationsService } from '../notifications/notifications.service';
-import { NotificationType } from '../database/entities/notification.entity';
+import { NotificationHelper } from '../notifications/notification.helper';
 import { CustomLoggerService } from '../logger/custom-logger.service';
 import { VaultGateway } from '../realtime/vault.gateway';
 import { ContractCacheService } from '../common/cache/contract-cache.service';
@@ -150,12 +150,12 @@ export class VaultsService {
     });
 
     if (amount >= LARGE_DEPOSIT_THRESHOLD) {
-      await this.notificationsService.create({
-        title: 'Large Deposit Alert',
-        message: `A large deposit of ${amount} has been initiated for vault ${vault.vaultName}.`,
-        type: NotificationType.LARGE_TRANSACTION,
-        adminOnly: true,
-      });
+      await this.notificationsService.create(
+        NotificationHelper.largeDepositAlert({
+          amount,
+          vaultName: vault.vaultName,
+        }),
+      );
     }
 
     const confirmedDeposit = await this.confirmDeposit(result.deposit.id);
@@ -209,12 +209,13 @@ export class VaultsService {
       throw new NotFoundException('Deposit not found after confirmation');
     }
 
-    await this.notificationsService.create({
-      userId: updatedDeposit.userId,
-      title: 'Deposit Confirmed',
-      message: `Your deposit of ${updatedDeposit.amount} into vault ${updatedDeposit.vaultId} has been confirmed.`,
-      type: NotificationType.DEPOSIT,
-    });
+    await this.notificationsService.create(
+      NotificationHelper.depositConfirmed({
+        userId: updatedDeposit.userId,
+        amount: updatedDeposit.amount,
+        vaultId: updatedDeposit.vaultId,
+      }),
+    );
 
     return updatedDeposit;
   }
@@ -350,12 +351,13 @@ export class VaultsService {
       throw new NotFoundException('Withdrawal not found after confirmation');
     }
 
-    await this.notificationsService.create({
-      userId,
-      title: 'Withdrawal Confirmed',
-      message: `Your withdrawal of ${amount} from vault ${vault.vaultName} has been confirmed.`,
-      type: NotificationType.DEPOSIT,
-    });
+    await this.notificationsService.create(
+      NotificationHelper.withdrawalConfirmed({
+        userId,
+        amount,
+        vaultName: vault.vaultName,
+      }),
+    );
 
     this.logger.log(
       `Withdrawal of ${amount} confirmed from vault ${vaultId} by user ${userId}`,