src/transaction/transaction.controller.spec.ts

@@ -70,9 +70,9 @@ describe('TransactionController Unit Tests', () => {
   });
 
   it('calling applyRules method minimum result of applied rules should be got', async () => {
-    const mockTransactionInput: TransactionInput = {
+    const mockTransactionInput = {
       date: '2021-01-05',
-      amount: '1000.00',
+      base_amount: 1000.0,
       currency: 'EUR',
       client_id: 1,
     };

src/transaction/transaction.controller.ts

@@ -1,4 +1,5 @@
 import { Controller, Post, UsePipes, Body } from '@nestjs/common';
+import { ExchangeRateInput, ExchangeRateResponse } from 'src/exchange-rate/exchange-rate.dto';
 import { ExchangeRateService } from 'src/exchange-rate/exchange-rate.service';
 import { TransactionService } from './transaction.service';
 import { transactionBodySchema } from './transaction.validation';
@@ -11,6 +12,9 @@ import {
   DefaultCommissionAmount,
   HighTurnoverDiscount,
 } from './transaction.dto';
+import { Transaction } from './transaction.entity';
+
+type TransactionRuleData = Pick<Transaction, 'base_amount' | 'client_id'>;
 
 @Controller('transaction')
 export class TransactionController {
@@ -37,7 +41,7 @@ export class TransactionController {
     });
   }
 
-  getClientDeposit = async (transactionInput: TransactionInput) => {
+  getClientDeposit = async (transactionInput: TransactionRuleData) => {
     try {
       const deposit =
         await this.transactionService.findByClientIdWithinActualMonth(
@@ -60,7 +64,7 @@ export class TransactionController {
     return 0;
   };
 
-  turnoverRule = async (transactionInput: TransactionInput) => {
+  turnoverRule = async (transactionInput: TransactionRuleData) => {
     try {
       const clientDeposit = await this.getClientDeposit(transactionInput);
       if (clientDeposit) {
@@ -71,24 +75,26 @@ export class TransactionController {
     }
   };
 
-  discountRule(transactionInput: TransactionInput) {
+  discountRule(transactionInput: TransactionRuleData) {
     return transactionInput.client_id === 42
       ? DiscountRuleForClientById.client_42
       : false;
   }
 
-  defaultRule(transactionInput: TransactionInput) {
+  defaultRule(transactionInput: TransactionRuleData) {
     const commissionAmount =
-      (parseInt(transactionInput.amount) / 100) *
-      DefaultCommissionPercentage.percentage;
+      (transactionInput.base_amount * DefaultCommissionPercentage.percentage) /
+      100;
     return commissionAmount < DefaultCommissionAmount.amount
       ? DefaultCommissionAmount.amount
       : commissionAmount;
   }
 
   async applyRules(
-    rules: ((transactionInput: TransactionInput) => any)[],
-    transactionInput: TransactionInput,
+    rules: ((
+      transactionInput: TransactionRuleData,
+    ) => number | false | undefined | Promise<number | false | undefined>)[],
+    transactionInput: TransactionRuleData,
   ) {
     let commissionAmount;
     for (let i = 0; i < rules.length; i++) {
@@ -105,60 +111,71 @@ export class TransactionController {
       : this.defaultRule(transactionInput);
   }
 
-  getAmountWithExchange(transactionInput: TransactionInput) {
-    const commissionAmount = this.applyRules(
-      [this.turnoverRule, this.discountRule],
-      transactionInput,
-    );
+  getExchangeRate(exchangeRateInput: ExchangeRateInput) {
+    return new Promise<ExchangeRateResponse>((resolve, reject) => {
+      try {
+        this.exchangeRateService.convertCurrency(exchangeRateInput).subscribe({
+          next: resolve,
+          error: reject,
+        });
+      } catch (error) {
+        reject(error);
+      }
+    });
+  }
 
-    const exhangeRateInput = {
+  async getAmountWithExchange(transactionInput: TransactionInput) {
+    const exchangeRateResponse = await this.getExchangeRate({
       date: transactionInput.date,
-    };
+    });
 
-    try {
-      this.exchangeRateService.convertCurrency(exhangeRateInput).subscribe({
-        next: (exchangeRateResponse) =>
-          commissionAmount
-            .then((commission) =>
-              this.transactionService.insertOne({
+    const transactionAmount = parseInt(transactionInput.amount);
+    const transactionData = {
       date: transactionInput.date,
-                amount: parseInt(transactionInput.amount),
+      amount: transactionAmount,
       currency: transactionInput.currency,
       client_id: transactionInput.client_id,
-                commission,
       base_currency: Currency.EUR,
       base_amount:
-                  parseInt(transactionInput.amount) *
-                  exchangeRateResponse[transactionInput.currency],
+        transactionAmount / exchangeRateResponse[transactionInput.currency],
+    };
+
+    const commissionAmount = this.applyRules(
+      [this.turnoverRule, this.discountRule],
+      transactionData,
+    );
+
+    commissionAmount
+      .then((commission) =>
+        this.transactionService.insertOne({
+          ...transactionData,
+          commission,
         }),
       )
-            .catch((error) => console.log(error)),
-        error: (error) => {
-          console.log(error);
-        },
-      });
-    } catch (error) {
-      console.log(error);
-    }
+      .catch((error) => console.log(error));
 
     return commissionAmount;
   }
 
   async getAmountWithoutExchange(transactionInput: TransactionInput) {
+    const transactionData = {
+      date: transactionInput.date,
+      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(
       [this.turnoverRule, this.discountRule],
-      transactionInput,
+      transactionData,
     );
     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) {