Merge pull request #6 from devzero-inc/feature/unit-test-05

#5 AS: refactored backend code, written unit tests for the app

backend/app.py

@@ -1,83 +1,14 @@
-from flask import Flask, jsonify, request
-import mysql.connector
-from mysql.connector import Error
-import os
+from flask import Flask
+from flask_cors import CORS
 from dotenv import load_dotenv
-from flask_cors import CORS 
-
-app = Flask(__name__)
-CORS(app)
+import routes
 
 load_dotenv()
 
-DATABASE_CONFIG = {
-    'host': os.getenv('DB_HOST'),
-    'database': os.getenv('DB_DATABASE'),
-    'user': os.getenv('DB_USER'),
-    'password': os.getenv('DB_PASSWORD')
-}
-
-def get_db_connection():
-    try:
-        conn = mysql.connector.connect(**DATABASE_CONFIG)
-        if conn.is_connected():
-            return conn
-    except Error as e:
-        print(f"Error connecting to MySQL Database: {e}")
-        return None
-
-@app.route('/accounts', methods=['GET'])
-def get_accounts():
-    conn = get_db_connection()
-    if conn:
-        cursor = conn.cursor(dictionary=True)
-        cursor.execute('SELECT * FROM accounts')
-        accounts = cursor.fetchall()
-        cursor.close()
-        conn.close()
-        return jsonify({"data": accounts})
-    else:
-        return jsonify({"error": "Database connection failed"}), 500
+app = Flask(__name__)
+CORS(app)
 
-@app.route('/transactions', methods=['GET'])
-def get_transactions():
-    conn = get_db_connection()
-    if conn:
-        cursor = conn.cursor(dictionary=True)
-        cursor.execute('SELECT * FROM transactions')
-        transactions = cursor.fetchall()
-        cursor.close()
-        conn.close()
-        return jsonify({"data": transactions})
-    else:
-        return jsonify({"error": "Database connection failed"}), 500
-
-@app.route('/transactions', methods=['POST'])
-def add_transaction():
-    transaction_data = request.json
-    conn = get_db_connection()
-    if conn:
-        cursor = conn.cursor()
-        cursor.execute(
-            'INSERT INTO transactions '
-            '(account_id, bank_name, date, type, payee, amount, category) '
-            'VALUES (%s, %s, %s, %s, %s, %s, %s)',
-            (
-                transaction_data['account_id'],
-                transaction_data['bank_name'],
-                transaction_data['date'],
-                transaction_data['type'],
-                transaction_data['payee'],
-                transaction_data['amount'],
-                transaction_data['category']
-            )
-        )
-        conn.commit()
-        cursor.close()
-        conn.close()
-        return jsonify({"message": "Transaction added successfully"}), 201
-    else:
-        return jsonify({"error": "Database connection failed"}), 500
+app.register_blueprint(routes.api)
 
 if __name__ == "__main__":
     app.run(debug=True)

backend/config.py

@@ -0,0 +1,8 @@
+import os
+
+DATABASE_CONFIG = {
+    'host': os.getenv('DB_HOST'),
+    'database': os.getenv('DB_DATABASE'),
+    'user': os.getenv('DB_USER'),
+    'password': os.getenv('DB_PASSWORD')
+}

backend/databaseService.py

@@ -0,0 +1,49 @@
+from db import get_db_connection
+
+def fetch_all_accounts():
+    conn = get_db_connection()
+    if conn:
+        cursor = conn.cursor(dictionary=True)
+        cursor.execute('SELECT * FROM accounts')
+        accounts = cursor.fetchall()
+        cursor.close()
+        conn.close()
+        return accounts, None
+    else:
+        return None, "Database connection failed"
+
+def fetch_all_transactions():
+    conn = get_db_connection()
+    if conn:
+        cursor = conn.cursor(dictionary=True)
+        cursor.execute('SELECT * FROM transactions')
+        transactions = cursor.fetchall()
+        cursor.close()
+        conn.close()
+        return transactions, None
+    else:
+        return None, "Database connection failed"
+
+def insert_transaction(transaction_data):
+    conn = get_db_connection()
+    if conn:
+        cursor = conn.cursor()
+        cursor.execute(
+            'INSERT INTO transactions (account_id, bank_name, date, type, payee, amount, category) '
+            'VALUES (%s, %s, %s, %s, %s, %s, %s)',
+            (
+                transaction_data['account_id'],
+                transaction_data['bank_name'],
+                transaction_data['date'],
+                transaction_data['type'],
+                transaction_data['payee'],
+                transaction_data['amount'],
+                transaction_data['category']
+            )
+        )
+        conn.commit()
+        cursor.close()
+        conn.close()
+        return "Transaction added successfully", None
+    else:
+        return None, "Database connection failed"

backend/db.py

@@ -0,0 +1,13 @@
+import mysql.connector
+from mysql.connector import Error
+from config import DATABASE_CONFIG
+
+def get_db_connection():
+    try:
+        conn = mysql.connector.connect(**DATABASE_CONFIG)
+        if conn.is_connected():
+            print("Connected to MySQL database")
+            return conn
+    except Error as e:
+        print(f"Error connecting to MySQL Database: {e}")
+    return None

backend/routes.py

@@ -0,0 +1,33 @@
+from flask import Blueprint, jsonify, request
+from databaseService import fetch_all_accounts, fetch_all_transactions, insert_transaction
+
+api = Blueprint('api', __name__)
+
+@api.route('/health', methods=['GET'])
+def health_check():
+    return jsonify({"message": "Server is running"})
+
+@api.route('/accounts', methods=['GET'])
+def get_accounts():
+    accounts, error = fetch_all_accounts()
+    if error:
+        return jsonify({"error": error}), 500
+    else:
+        return jsonify({"data": accounts})
+
+@api.route('/transactions', methods=['GET'])
+def get_transactions():
+    transactions, error = fetch_all_transactions()
+    if error:
+        return jsonify({"error": error}), 500
+    else:
+        return jsonify({"data": transactions})
+
+@api.route('/transactions', methods=['POST'])
+def add_transaction():
+    transaction_data = request.json
+    message, error = insert_transaction(transaction_data)
+    if error:
+        return jsonify({"error": error}), 500
+    else:
+        return jsonify({"message": message}), 201

backend/tests/test_db.py

@@ -0,0 +1,21 @@
+import unittest
+from unittest.mock import patch
+from db import get_db_connection
+import mysql.connector
+
+class TestDatabaseConnection(unittest.TestCase):
+
+    @patch('mysql.connector.connect')
+    def test_get_db_connection_success(self, mock_connect):
+        mock_connect.return_value.is_connected.return_value = True
+        conn = get_db_connection()
+        self.assertTrue(conn.is_connected())
+
+    @patch('mysql.connector.connect')
+    def test_get_db_connection_failure(self, mock_connect):
+        mock_connect.side_effect = mysql.connector.Error("Connection failed")
+        conn = get_db_connection()
+        self.assertIsNone(conn)
+
+if __name__ == '__main__':
+    unittest.main()

backend/tests/test_routes.py

@@ -0,0 +1,56 @@
+import unittest
+from unittest.mock import patch
+from app import app
+
+class TestFlaskRoutes(unittest.TestCase):
+    def setUp(self):
+        self.app = app.test_client()
+        self.app.testing = True
+
+    def test_health_check(self):
+        response = self.app.get('/health')
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json, {"message": "Server is running"})
+
+    @patch('routes.fetch_all_accounts')
+    def test_get_accounts(self, mock_fetch_all_accounts):
+        mock_fetch_all_accounts.return_value = ([
+            {"id": 1, "name": "Account 1", "balance": 1000},
+            {"id": 2, "name": "Account 2", "balance": 2000},
+        ], None)
+
+        response = self.app.get('/accounts')
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json, {"data": mock_fetch_all_accounts.return_value[0]})
+
+    @patch('routes.fetch_all_transactions')
+    def test_get_transactions(self, mock_fetch_all_transactions):
+        mock_fetch_all_transactions.return_value = ([
+            {"id": 1, "account_id": 1, "payee": "Netflix", "amount": -15, "category": "Entertainment"},
+            {"id": 2, "account_id": 2, "payee": "Grocery Store", "amount": -100, "category": "Groceries"},
+        ], None)
+
+        response = self.app.get('/transactions')
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json, {"data": mock_fetch_all_transactions.return_value[0]})
+
+    @patch('routes.insert_transaction')
+    def test_add_transaction(self, mock_insert_transaction):
+        mock_insert_transaction.return_value = ("Transaction added successfully", None)
+
+        transaction_data = {
+            "account_id": "1",
+            "bank_name": "Test Bank",
+            "date": "2022-01-01",
+            "type": "debit",
+            "payee": "New Payee",
+            "amount": 50,
+            "category": "Test Category",
+        }
+
+        response = self.app.post('/transactions', json=transaction_data)
+        self.assertEqual(response.status_code, 201)
+        self.assertEqual(response.json, {"message": "Transaction added successfully"})
+
+if __name__ == '__main__':
+    unittest.main()

frontend/jest.config.cjs

@@ -0,0 +1,18 @@
+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+  moduleNameMapper: {
+    "^@/(.*)$": "<rootDir>/src/$1",
+  },
+  transform: {
+    "^.+\\.ts$": "ts-jest",
+  },
+  globals: {
+    "ts-jest": {
+      useESM: true,
+      tsconfig: '<rootDir>/tsconfig.spec.json'
+    },
+  },
+  extensionsToTreatAsEsm: [".ts"],
+  testMatch: ["**/__tests__/**/*.ts?(x)", "**/?(*.)+(spec|test).ts?(x)"],
+};