package-lock.json

@@ -17,6 +17,7 @@
         "axios": "0.26.1",
         "chai-as-promised": "^7.1.1",
         "joi": "17.6.0",
+        "lodash": "^4.17.21",
         "reflect-metadata": "0.1.13",
         "rimraf": "3.0.2",
         "rxjs": "7.5.5",
@@ -29,6 +30,7 @@
         "@types/express": "4.17.13",
         "@types/jest": "27.4.1",
         "@types/joi": "17.2.3",
+        "@types/lodash": "^4.14.202",
         "@types/node": "16.0.0",
         "@types/supertest": "2.0.11",
         "@typescript-eslint/eslint-plugin": "5.0.0",
@@ -2157,6 +2159,12 @@
       "integrity": "sha512-wOuvG1SN4Us4rez+tylwwwCV1psiNVOkJeM3AUWUNWg/jDQY2+HE/444y5gc+jBmRqASOm2Oeh5c1axHobwRKQ==",
       "dev": true
     },
+    "node_modules/@types/lodash": {
+      "version": "4.14.202",
+      "resolved": "https://registry.npmjs.org/@types/lodash/-/lodash-4.14.202.tgz",
+      "integrity": "sha512-OvlIYQK9tNneDlS0VN54LLd5uiPCBOp7gS5Z0f1mjoJYBrtStzgmJBxONW3U6OZqdtNzZPmn9BS/7WI7BFFcFQ==",
+      "dev": true
+    },
     "node_modules/@types/mime": {
       "version": "1.3.2",
       "resolved": "https://registry.npmjs.org/@types/mime/-/mime-1.3.2.tgz",
@@ -7032,8 +7040,7 @@
     "node_modules/lodash": {
       "version": "4.17.21",
       "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
-      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
-      "dev": true
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
     },
     "node_modules/lodash.merge": {
       "version": "4.6.2",
@@ -12381,6 +12388,12 @@
       "integrity": "sha512-wOuvG1SN4Us4rez+tylwwwCV1psiNVOkJeM3AUWUNWg/jDQY2+HE/444y5gc+jBmRqASOm2Oeh5c1axHobwRKQ==",
       "dev": true
     },
+    "@types/lodash": {
+      "version": "4.14.202",
+      "resolved": "https://registry.npmjs.org/@types/lodash/-/lodash-4.14.202.tgz",
+      "integrity": "sha512-OvlIYQK9tNneDlS0VN54LLd5uiPCBOp7gS5Z0f1mjoJYBrtStzgmJBxONW3U6OZqdtNzZPmn9BS/7WI7BFFcFQ==",
+      "dev": true
+    },
     "@types/mime": {
       "version": "1.3.2",
       "resolved": "https://registry.npmjs.org/@types/mime/-/mime-1.3.2.tgz",
@@ -16120,8 +16133,7 @@
     "lodash": {
       "version": "4.17.21",
       "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
-      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
-      "dev": true
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
     },
     "lodash.merge": {
       "version": "4.6.2",

package.json

@@ -30,6 +30,7 @@
     "axios": "0.26.1",
     "chai-as-promised": "^7.1.1",
     "joi": "17.6.0",
+    "lodash": "^4.17.21",
     "reflect-metadata": "0.1.13",
     "rimraf": "3.0.2",
     "rxjs": "7.5.5",
@@ -42,6 +43,7 @@
     "@types/express": "4.17.13",
     "@types/jest": "27.4.1",
     "@types/joi": "17.2.3",
+    "@types/lodash": "^4.14.202",
     "@types/node": "16.0.0",
     "@types/supertest": "2.0.11",
     "@typescript-eslint/eslint-plugin": "5.0.0",

src/transaction/transaction.controller.spec.ts

@@ -20,7 +20,7 @@ describe('TransactionController Unit Tests', () => {
           Promise.reject(new Error('DatabaseNotReachable')),
         ),
         findByClientIdWithinActualMonth: jest.fn((clientId) => {
-          if (clientId === 42) {
+          if (clientId === 42 || clientId === 99) {
             return [{ base_amount: 1500 }];
           }
           return [];
@@ -70,19 +70,95 @@ describe('TransactionController Unit Tests', () => {
   });
 
   it('calling applyRules method minimum result of applied rules should be got', async () => {
-    const mockTransactionInput = {
-      date: '2021-01-05',
-      base_amount: 1000.0,
-      currency: 'EUR',
+    {
+      const result = await transactionController.applyRules(
+        [
+          transactionController.discountRule,
+          transactionController.turnoverRule,
+        ],
+        {
+          base_amount: 1000,
           client_id: 1,
-    };
+        },
+      );
 
+      expect(result).to.eql(5);
+    }
+
+    {
       const result = await transactionController.applyRules(
-      [transactionController.discountRule, transactionController.turnoverRule],
-      mockTransactionInput,
+        [
+          transactionController.discountRule,
+          transactionController.turnoverRule,
+        ],
+        {
+          base_amount: 1,
+          client_id: 1,
+        },
       );
 
-    expect(result).to.eql(5);
+      expect(result).to.eql(0.05);
+    }
+
+    {
+      const result = await transactionController.applyRules(
+        [
+          transactionController.discountRule,
+          transactionController.turnoverRule,
+        ],
+        {
+          base_amount: 1000,
+          client_id: 42,
+        },
+      );
+
+      expect(result).to.eql(0.03);
+    }
+
+    {
+      const result = await transactionController.applyRules(
+        [
+          transactionController.discountRule,
+          transactionController.turnoverRule,
+        ],
+        {
+          base_amount: 1,
+          client_id: 42,
+        },
+      );
+
+      expect(result).to.eql(0.03);
+    }
+
+    {
+      const result = await transactionController.applyRules(
+        [
+          transactionController.discountRule,
+          transactionController.turnoverRule,
+        ],
+        {
+          base_amount: 1000,
+          client_id: 99,
+        },
+      );
+
+      expect(result).to.eql(0.03);
+    }
+
+    {
+      const result = await transactionController.applyRules(
+        [
+          transactionController.discountRule,
+          transactionController.turnoverRule,
+        ],
+        {
+          base_amount: 1,
+          client_id: 99,
+        },
+      );
+
+      expect(result).to.eql(0.03);
+    }
   });
 
   it('calling commission method correct commission should be got', async () => {

src/transaction/transaction.controller.ts

@@ -1,5 +1,9 @@
 import { Controller, Post, UsePipes, Body } from '@nestjs/common';
-import { ExchangeRateInput, ExchangeRateResponse } from 'src/exchange-rate/exchange-rate.dto';
+import _ from 'lodash';
+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';
@@ -31,12 +35,8 @@ export class TransactionController {
     return JSON.stringify({
       amount:
         transactionInput.currency !== Currency.EUR
-          ? parseFloat(
-              await this.getAmountWithExchange(transactionInput),
-            ).toFixed(2)
-          : parseFloat(
-              await this.getAmountWithoutExchange(transactionInput),
-            ).toFixed(2),
+          ? (await this.getAmountWithExchange(transactionInput)).toFixed(2)
+          : (await this.getAmountWithoutExchange(transactionInput)).toFixed(2),
       currency: Currency.EUR,
     });
   }
@@ -96,19 +96,10 @@ export class TransactionController {
     ) => number | false | undefined | Promise<number | false | undefined>)[],
     transactionInput: TransactionRuleData,
   ) {
-    let commissionAmount;
-    for (let i = 0; i < rules.length; i++) {
-      const ruleResult = await rules[i](transactionInput);
-      if (ruleResult) {
-        commissionAmount = ruleResult;
-        break;
-      } else {
-        continue;
-      }
-    }
-    return commissionAmount
-      ? commissionAmount
-      : this.defaultRule(transactionInput);
+    const commissions = await Promise.all(
+      [...rules, this.defaultRule].map((rule) => rule(transactionInput)),
+    );
+    return Math.min(..._.compact(commissions));
   }
 
   getExchangeRate(exchangeRateInput: ExchangeRateInput) {