What is The purpose of a test design technique
to identify test condition, test case, and test data
Why is A testing Technique important?
Effective
- Find more faults
- Focus attention on specific types of faults
- Know you are testing the right thing
Efficient
- Find faults with less efforts
- Avoid duplication
- Systematic techniques are measurable
What are the Categories of Test Design Techniques
- Specification-based
- Structure-based
- Experience based
… is Specification-based while … is Structure-based
Black Box , White Box
What are the Advantages of black-box testing
- focus on the functional behavior
- Independent from the internal code
- Can catch logic defects early
- Applicable at all levels of granularity
- allows for early test design
What are the Black-box testing process
Analyze requirements
Choose valid and invalid inputs
Determine expected outputs for those inputs
List the Black box testing techniques
Equivalence Partitioning
Boundary Value Analysis
Decision tables testing
State transition testing
Use case testing
What is Equivalence Partitioning (EP)
is a black-box testing technique that divides the input domain of a software system into different equivalence classes or partitions.
EP divides the possible inputs into groups called …
equivalence classes.
The rule for EP is to select one representative value from each equivalence class as a test case.
t
This ensures that each class is adequately tested, covering both valid and invalid inputs.
In EC, The partitioning is based on …
requirements of the software system
What is Challenging for the tester when using EC Testing?
- Different testers find different equivalence classes
- Finding an appropriate partition not knowing how the program looks inside.
How does Ep test invalid inputs
- For invalid equivalence classes, boundary values are often tested to ensure the system behaves as expected.
… is used only for valid inputs
Testing by contract
… and … weaken the need to
use defensive testing
- GUIs &
- Strong typed programming languages
how do GUIs and strong typed programming languages weaken the need to use defensive testing
- GUI elements often enforce certain constraints on user input and can prevent users from entering invalid data.
- GUI frameworks include built-in validation mechanisms
- Strongly typed programming languages enforce strict type checking at compile-time
- So they type-related errors before runtime
Given this Req : Age field can take the values in the range of 20 to 50. What is the best EP approach to test it?
Include these partitions :
- Below range - 10
- Within Range 20 to 50 - 40
- Above range - 60
- Whole numbers - 40
- Real numbers - 30.4
- Numbers - 40
- Characters - xyz
- +ve numbers - 40
- -ve numbers - -30
- 0-0
What is Failure Masking in Equivalence Partitioning
Failures can be masked when several failures occur at the same time but only one is visible, causing the other failures to undetected
What must be done To achieve 100% coverage with Equivalence Partitioning?
Test cases must cover all identified partitions (including invalid partitions) by using a minimum of one value from each partition
How do we calculate Equivalence Partitioning Coverage %
Total Number of Tested EP
/
Total Number of EP
How does Equivalence Partitioning work with Discrete Values?
- equivalence classes are formed based on the distinct values
Example : if a field accepts colors as input, the equivalence classes could be “Red,” “Blue,” “Green,” etc.
How does Equivalence Partitioning Multiple Conditions work given :
Age : (< 20),(20 >= and <=50), ( >50)
Country: (Egypt), (Canada), (USA), (India)
3 partitions + 4 partitions = 7 Partitions
Test cases
TC1:(10,Egypt)
TC2: (40,Canda)
TC3:(60,USA)
TC4:(45,India)
How did Boundary values testing (BV) come about?
a surprising nr. of faults turned out to be boundary value faults
BVT is most applicable when …
- inputs are constrained and fall within certain minimum and maximum limits.
- For boolean values has no sense.
