feat: implemented tests checking rules precedence (closes #13)

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 () => {