CRUD operation verification in Testing Fundamentals - Test Execution Trace

Test Overview

This test checks the basic Create, Read, Update, and Delete (CRUD) operations on a simple user record system. It verifies that each operation works correctly by asserting expected results after each step.

Test Code - unittest

Testing Fundamentals

import unittest

class TestCRUDOperations(unittest.TestCase):
    def setUp(self):
        # Simulate a simple in-memory user database as a dictionary
        self.users = {}

    def test_crud_operations(self):
        # Create operation
        self.users['user1'] = {'name': 'Alice', 'age': 30}
        self.assertIn('user1', self.users)
        self.assertEqual(self.users['user1']['name'], 'Alice')

        # Read operation
        user = self.users.get('user1')
        self.assertIsNotNone(user)
        self.assertEqual(user['age'], 30)

        # Update operation
        self.users['user1']['age'] = 31
        self.assertEqual(self.users['user1']['age'], 31)

        # Delete operation
        del self.users['user1']
        self.assertNotIn('user1', self.users)

if __name__ == '__main__':
    unittest.main()

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts and sets up an empty user dictionary	Empty dictionary for users initialized	—	PASS
2	Create operation: Adds user1 with name 'Alice' and age 30	users = {'user1': {'name': 'Alice', 'age': 30}}	Check user1 exists and name is 'Alice'	PASS
3	Read operation: Retrieves user1 data	users unchanged	Check user1 data is not None and age is 30	PASS
4	Update operation: Changes user1 age to 31	users = {'user1': {'name': 'Alice', 'age': 31}}	Check user1 age is updated to 31	PASS
5	Delete operation: Removes user1 from users	users = {}	Check user1 no longer exists in users	PASS

Failure Scenario

Failing Condition: If any CRUD operation does not perform as expected, such as missing user after creation or user still present after deletion

Execution Trace Quiz - 3 Questions

What does the test verify after the Create operation?

A User1 age is updated to 31

B User1 exists and has name 'Alice'

C User1 is deleted

D User1 data is None

Key Result

Always verify each CRUD operation separately with clear assertions to catch errors early and ensure data integrity.

Practice

1. Which CRUD operation is responsible for adding new data to a system?

easy

A. Delete

B. Read

C. Update

D. Create

Solution

1. Step 1: Understand CRUD operations

   CRUD stands for Create, Read, Update, and Delete, each representing a basic data operation.

2. Step 2: Identify the operation for adding data

   The 'Create' operation is used to add new data entries into the system.

3. Final Answer:

   Create -> Option D

4. Quick Check:

   Adding new data = Create [OK]

Hint: Create means add new data to the system [OK]

Common Mistakes:

• Confusing 'Create' with 'Update'
• Thinking 'Read' adds data
• Mixing 'Delete' with adding data

2. Which of the following is the correct syntax to verify a Delete operation in a test case?

easy

A. assert data.exists() == True

B. assert data.is_deleted() == True

C. assert data.count() > 0

D. assert data.is_present() == True

Solution

1. Step 1: Understand Delete verification

   To verify deletion, the test must confirm the data no longer exists or is marked deleted.

2. Step 2: Choose assertion that confirms deletion

   assert data.is_deleted() == True correctly checks that the data was deleted.

3. Final Answer:

   assert data.is_deleted() == True -> Option B

4. Quick Check:

   Delete check uses is_deleted() == True [OK]

Hint: Check deletion with is_deleted() == True [OK]

Common Mistakes:

• Using exists() == True after deletion
• Checking count() > 0 which means data exists
• Confusing is_present() with deletion status

3. Consider this test code snippet verifying an Update operation:

original_value = record.get('name')
record.update({'name': 'Alice'})
updated_value = record.get('name')
assert updated_value == 'Alice'

What will be the result of this test if the update works correctly?

medium

A. Test passes because updated_value matches 'Alice'

B. Test fails because original_value is not checked

C. Test fails due to syntax error in update method

D. Test passes but updated_value remains original_value

Solution

1. Step 1: Analyze the update operation

   The code updates the 'name' field to 'Alice' and retrieves it again.

2. Step 2: Check the assertion logic

   The assertion checks if updated_value equals 'Alice', which should be true if update works.

3. Final Answer:

   Test passes because updated_value matches 'Alice' -> Option A

4. Quick Check:

   Updated value == 'Alice' means test passes [OK]

Hint: Assert updated value equals new data after update [OK]

Common Mistakes:

• Assuming original_value must be checked in this test
• Thinking update method has syntax error
• Believing updated_value stays unchanged after update

4. A tester wrote this code to verify a Create operation:

new_record = db.create({'id': 1, 'value': 100})
assert new_record.id == 1
assert new_record.value == 100
assert db.find(1) == None

What is the error in this test?

medium

A. The assertion db.find(1) == None is incorrect after creation

B. The new_record object does not have id attribute

C. The create method should not return a record

D. The value 100 is not valid for creation

Solution

1. Step 1: Understand Create operation verification

   After creating a record, it should be found in the database.

2. Step 2: Analyze the assertion db.find(1) == None

   This assertion expects no record found, which contradicts the creation.

3. Final Answer:

   The assertion db.find(1) == None is incorrect after creation -> Option A

4. Quick Check:

   Created record must be found, so find(1) != None [OK]

Hint: After create, find should return the record, not None [OK]

Common Mistakes:

• Expecting find to return None after creation
• Assuming create returns nothing
• Confusing attribute existence on new_record

5. You want to verify all CRUD operations on a user profile. Which sequence of test steps is best to ensure data integrity?

hard

A. Create user, Update user, Delete user, Read user

B. Read user, Create user, Update user, Delete user

C. Create user, Read user, Update user, Delete user

D. Delete user, Create user, Read user, Update user

Solution

1. Step 1: Understand logical CRUD test order

   First, create data to have something to work with, then read to verify creation.

2. Step 2: Follow with update and delete

   Update tests changes, and delete confirms removal, maintaining data integrity.

3. Final Answer:

   Create user, Read user, Update user, Delete user -> Option C

4. Quick Check:

   CRUD order: Create, Read, Update, Delete [OK]

Hint: Test CRUD in order: Create, Read, Update, Delete [OK]

Common Mistakes:

• Deleting before creating data
• Reading before data exists
• Updating before creation