add error handling using python multiverseweb#201

software/ErrorHandling.py

@@ -0,0 +1,98 @@
+import tkinter as tk
+from tkinter import messagebox
+import unittest
+import sqlite3
+
+# Database connection function
+def connect_to_db():
+    try:
+        conn = sqlite3.connect('database.sql')
+        return conn
+    except sqlite3.Error as e:
+        messagebox.showerror("Database Error", f"Failed to connect to database: {e}")
+        return None
+
+# Function to check credentials
+def check_credentials(username, password):
+    if not username or not password:
+        messagebox.showerror("Invalid Input", "Username and password cannot be empty")
+        return False
+
+    conn = connect_to_db()
+    if conn is None:
+        return False
+
+    try:
+        cursor = conn.cursor()
+        cursor.execute("SELECT * FROM users WHERE username=? AND password=?", (username, password))
+        result = cursor.fetchone()
+        conn.close()
+        if result:
+            return True
+        else:
+            messagebox.showerror("Invalid Credentials", "Username or password is incorrect")
+            return False
+    except sqlite3.Error as e:
+        messagebox.showerror("Database Error", f"Failed to check credentials: {e}")
+        return False
+
+# Function to fetch data
+def fetch_data(u_id):
+    if not isinstance(u_id, int) or u_id <= 0:
+        messagebox.showerror("Invalid Input", "User ID must be a positive integer")
+        return None
+
+    conn = connect_to_db()
+    if conn is None:
+        return None
+
+    try:
+        cursor = conn.cursor()
+        cursor.execute("SELECT * FROM data WHERE u_id=?", (u_id,))
+        result = cursor.fetchone()
+        conn.close()
+        if result:
+            return result
+        else:
+            messagebox.showerror("No Data Found", "No data found for the given user ID")
+            return None
+    except sqlite3.Error as e:
+        messagebox.showerror("Database Error", f"Failed to fetch data: {e}")
+        return None
+
+# Function to decrypt data
+def decrypt(data):
+    if not data or len(data) % 2 != 0:
+        messagebox.showerror("Invalid Input", "Data must be a non-empty string with even length")
+        return None
+
+    # Decrypt logic here
+    return data
+
+class TestErrorHandling(unittest.TestCase):
+
+    def test_check_credentials_valid_input(self):
+        self.assertTrue(check_credentials("test_user", "test_password"))
+
+    def test_check_credentials_invalid_input(self):
+        self.assertFalse(check_credentials("", "test_password"))
+        self.assertFalse(check_credentials("test_user", ""))
+        self.assertFalse(check_credentials("", ""))
+
+    def test_fetch_data_valid_input(self):
+        self.assertIsNotNone(fetch_data(1))
+
+    def test_fetch_data_invalid_input(self):
+        self.assertIsNone(fetch_data(0))
+        self.assertIsNone(fetch_data(-1))
+        self.assertIsNone(fetch_data("test"))
+
+    def test_decrypt_valid_input(self):
+        self.assertIsNotNone(decrypt("test_data"))
+
+    def test_decrypt_invalid_input(self):
+        self.assertIsNone(decrypt(""))
+        self.assertIsNone(decrypt("test"))
+
+if __name__ == "__main__":
+    unittest.main()