Data validation rules in Testing Fundamentals - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are data validation rules in software testing?

Data validation rules are checks that ensure the data entered into a system is correct, complete, and useful before processing.

beginner

Why is data validation important in software applications?

It prevents errors, protects data integrity, and improves user experience by catching mistakes early.

beginner

Name three common types of data validation rules.

1. Format checks (e.g., email format)
2. Range checks (e.g., age between 1 and 120)
3. Presence checks (e.g., mandatory fields not empty)

beginner

What is a range check in data validation?

A range check ensures that a numeric or date value falls within a specified minimum and maximum limit.

beginner

How does a format check help in data validation?

It verifies that data matches a required pattern, like checking if a phone number has the right number of digits.

Which of the following is NOT a common data validation rule?

A Presence check

B Color check

C Range check

D Format check

Color check is not a standard data validation rule; presence, range, and format checks are common.

What does a presence check validate?

A Data is not empty

B Data is unique

C Data matches a pattern

D Data is within a range

Presence check ensures that a required field is not left empty.

Why should data validation be done before processing data?

A To slow down the system

B To make the user enter data twice

C To delete all data

D To prevent invalid data from causing errors

Validating data early prevents errors and protects system integrity.

Which validation rule would check if an email address contains '@'?

A Format check

B Presence check

C Range check

D Uniqueness check

Format check verifies that data matches a required pattern, like an email format.

If a field requires a number between 1 and 100, which validation rule applies?

A Presence check

B Format check

C Range check

D Length check

Range check ensures the number falls within the specified limits.

Explain what data validation rules are and why they matter in software testing.

Think about how checking data before use helps avoid problems.

List and describe three common types of data validation rules with examples.

Consider mandatory fields, numeric limits, and pattern matching.

Practice

1. What is the main purpose of data validation rules in software testing?

easy

A. To check if input data is correct and useful

B. To improve the speed of the software

C. To change the data format automatically

D. To delete old data from the system

Solution

1. Step 1: Understand the role of data validation

   Data validation rules are designed to check input data for correctness and usefulness before processing.

2. Step 2: Compare options with the definition

   Only To check if input data is correct and useful correctly states this purpose; others describe unrelated tasks.

3. Final Answer:

   To check if input data is correct and useful -> Option A

4. Quick Check:

   Data validation = Check correctness [OK]

Hint: Validation means checking data correctness early [OK]

Common Mistakes:

• Confusing validation with data transformation
• Thinking validation improves software speed
• Assuming validation deletes data

2. Which of the following is a correct example of a data validation rule for an email field?

easy

A. The field must contain only numbers

B. The field must not be empty and must contain '@' symbol

C. The field must be exactly 5 characters long

D. The field must be left blank

Solution

1. Step 1: Identify common email validation rules

   Email fields require non-empty input and must include '@' to be valid.

2. Step 2: Evaluate each option

   The field must not be empty and must contain '@' symbol matches these rules; A, B, and D do not fit email validation.

3. Final Answer:

   The field must not be empty and must contain '@' symbol -> Option B

4. Quick Check:

   Email validation = Non-empty + '@' [OK]

Hint: Emails always need '@' and something before/after [OK]

Common Mistakes:

• Checking length without '@' for emails
• Allowing empty email fields
• Restricting emails to numbers only

3. Consider this validation rule in a test script:

assert age >= 18 and age <= 65

What will happen if age = 70 during test execution?

medium

A. Test will ignore the age value

B. Test will pass because 70 is a valid age

C. Test will raise a syntax error

D. Test will fail because 70 is outside the valid range

Solution

1. Step 1: Understand the validation condition

   The rule requires age to be between 18 and 65 inclusive.

2. Step 2: Check the given age value

   Age 70 is greater than 65, so the condition fails and assertion fails.

3. Final Answer:

   Test will fail because 70 is outside the valid range -> Option D

4. Quick Check:

   Age 70 > 65 = Fail [OK]

Hint: Check if value fits the range in assertion [OK]

Common Mistakes:

• Assuming test passes if value is above max
• Confusing syntax error with assertion failure
• Ignoring assertion conditions

4. A tester wrote this validation rule:

assert len(username) > 0 and len(username) < 15

What is the problem with this rule if the username length is exactly 15?

medium

A. The test will fail because 15 is not less than 15

B. The test will pass because 15 is allowed

C. The test will cause a runtime error

D. The test will ignore the username length

Solution

1. Step 1: Analyze the length condition

   The rule requires username length to be greater than 0 and less than 15.

2. Step 2: Check the boundary value 15

   Length 15 is not less than 15, so assertion fails.

3. Final Answer:

   The test will fail because 15 is not less than 15 -> Option A

4. Quick Check:

   Length 15 < 15? No = Fail [OK]

Hint: Check if boundary values are included or excluded [OK]

Common Mistakes:

• Assuming less than includes the number itself
• Ignoring boundary conditions
• Thinking test causes error instead of fail

5. You need to validate a form field that accepts only positive integers less than 1000 and not empty. Which combined validation rule is correct?

hard

A. assert value.isalpha() and int(value) > 0

B. assert value != '' and int(value) >= 1000

C. assert value.isdigit() and 0 < int(value) < 1000

D. assert value == '' or int(value) < 0

Solution

1. Step 1: Understand the requirements

   Value must be non-empty, only digits, positive, and less than 1000.

2. Step 2: Evaluate each option

   assert value.isdigit() and 0 < int(value) < 1000 checks digits only, converts to int, and tests range correctly. Others fail one or more conditions.

3. Final Answer:

   assert value.isdigit() and 0 < int(value) < 1000 -> Option C

4. Quick Check:

   Digits + positive + <1000 = assert value.isdigit() and 0 < int(value) < 1000 [OK]

Hint: Check digits, non-empty, and range in one assertion [OK]

Common Mistakes:

• Using isalpha() instead of isdigit()
• Allowing empty strings
• Checking wrong numeric ranges