fix: use base_amount to calculate commission

src/transaction/transaction.controller.spec.ts

@@ -72,7 +72,7 @@ describe('TransactionController Unit Tests', () => {
   it('calling applyRules method minimum result of applied rules should be got', async () => {
     const mockTransactionInput = {
       date: '2021-01-05',
-      amount: 1000.0,
+      base_amount: 1000.0,
       currency: 'EUR',
       client_id: 1,
     };

src/transaction/transaction.controller.ts

@@ -14,7 +14,7 @@ import {
 } from './transaction.dto';
 import { Transaction } from './transaction.entity';
 
-type TransactionRuleData = Pick<Transaction, 'amount' | 'client_id'>;
+type TransactionRuleData = Pick<Transaction, 'base_amount' | 'client_id'>;
 
 @Controller('transaction')
 export class TransactionController {
@@ -83,7 +83,8 @@ export class TransactionController {
 
   defaultRule(transactionInput: TransactionRuleData) {
     const commissionAmount =
-      (transactionInput.amount * DefaultCommissionPercentage.percentage) / 100;
+      (transactionInput.base_amount * DefaultCommissionPercentage.percentage) /
+      100;
     return commissionAmount < DefaultCommissionAmount.amount
       ? DefaultCommissionAmount.amount
       : commissionAmount;
@@ -123,12 +124,20 @@ export class TransactionController {
     });
   }
 
-  getAmountWithExchange(transactionInput: TransactionInput) {
+  async getAmountWithExchange(transactionInput: TransactionInput) {
+    const exchangeRateResponse = await this.getExchangeRate({
+      date: transactionInput.date,
+    });
+
+    const transactionAmount = parseInt(transactionInput.amount);
     const transactionData = {
       date: transactionInput.date,
-      amount: parseInt(transactionInput.amount),
+      amount: transactionAmount,
       currency: transactionInput.currency,
       client_id: transactionInput.client_id,
+      base_currency: Currency.EUR,
+      base_amount:
+        transactionAmount * exchangeRateResponse[transactionInput.currency],
     };
 
     const commissionAmount = this.applyRules(
@@ -136,22 +145,12 @@ export class TransactionController {
       transactionData,
     );
 
-    const exhangeRateInput = {
-      date: transactionInput.date,
-    };
-
-    this.getExchangeRate(exhangeRateInput)
-      .then((exchangeRateResponse) =>
-        commissionAmount.then((commission) =>
-          this.transactionService.insertOne({
-            ...transactionData,
-            commission,
-            base_currency: Currency.EUR,
-            base_amount:
-              parseInt(transactionInput.amount) *
-              exchangeRateResponse[transactionInput.currency],
-          }),
-        ),
+    commissionAmount
+      .then((commission) =>
+        this.transactionService.insertOne({
+          ...transactionData,
+          commission,
+        }),
       )
       .catch((error) => console.log(error));
 
@@ -164,6 +163,8 @@ export class TransactionController {
       amount: parseInt(transactionInput.amount),
       currency: transactionInput.currency,
       client_id: transactionInput.client_id,
+      base_currency: Currency.EUR,
+      base_amount: parseInt(transactionInput.amount),
     };
 
     const commissionAmount = await this.applyRules(
@@ -173,13 +174,8 @@ export class TransactionController {
     try {
       this.transactionService
         .insertOne({
-          date: transactionInput.date,
-          amount: parseInt(transactionInput.amount),
-          currency: transactionInput.currency,
-          client_id: transactionInput.client_id,
+          ...transactionData,
           commission: commissionAmount,
-          base_currency: Currency.EUR,
-          base_amount: parseInt(transactionInput.amount),
         })
         .catch((error) => console.log(error));
     } catch (error) {