Week 3 & 4

Question 1

What is software testing

Answer 1

process of evaluating a software solution to ensure it behaves as expected

Question 2

What is a bug

Answer 2

a bug or defect is a fault of either errors in software or hardware causing a system to fail

Question 3

why do we test

Answer 3

Finding defects
ensuring quality
validating requirements
improving user experience

Question 4

With proper testing can we ensure no bugs

Answer 4

Nah bro, shit isn’t that simple
can never be 100% but using proper testing methodology we can get close.

Question 5

What is Test Driven Development

Answer 5

TDD is a development approach where test are written before any implementation of code.

First plan how you can verify you results meets a goal before any UML , source code etc.

Question 6

what is the cycle involved in TDD

Answer 6

Red green refactor cycle

red = write a failing test, it will fail initially because of no code.

green = implement minimal code to pass the test

refactor = improve design, readability, maintainability etc while making tests cases still pass.

Question 7

Which methodology does TDD fall under

Answer 7

It is iterative
after code is refactored, cycle repeats adding more test cases

Question 8

TDD pros

Answer 8

improved code quality - write modular and readable code

reduced bugs - continuously testing and catching early

faster feedback - rapid feedback and address issues faster

better documentation - tests serve as documentation by showing intended behaviour and examples of usage

Question 9

wie se testcase

Answer 9

particular choice of input and expected output

Question 10

whats a test

Answer 10

finite collection of test cases

Question 11

What is white box testing

Answer 11

Testing the internal structure, design and code
done by dev team - need to understand the code and algorithms

Question 12

What is black box testing

Answer 12

testing the system from perspective of end users
done by end users

Question 13

so we cannot completely test systems, so how do we test.

Answer 13

basically that correct behaviour on critical parts represent correct behaviour on untested parts.

Question 14

is acceptance tests white or black? hehe

Answer 14

its black box
don’t need to understand working of code

Question 15

What are the broad testing seen in a logical organisation of testing

Answer 15

Unit testing
Integration testing
system testing

Question 16

Unit testing?

Answer 16

smallest possible parts of a system are tested individually and independently

white

Question 17

what is integration testing

Answer 17

Testing how components of a system interact with each other

white

Question 18

what is system testing and its 4 applications

Answer 18

System testing involves testing the entire system

white
Functional testing
Quality testing - non functional stuff

black
Acceptance testing
Installation testing - works when deployed

Question 19

what is coverage

Answer 19

helps us measure the degree of which the software program is tested

Test coverage - specification testing like acceptance tests

Code coverage - testing code like unit tests

Question 20

Do all tests weigh the same

Answer 20

No, testing can be prioritised because some tests can likely reveal more faults than others

Question 21

What are some testing techniques to achieving high coverage

Answer 21

Black
equivalence testing
boundary testing

white
control flow testing
state based testing

Question 22

what is equivalence testing

Answer 22

dividing possible inputs into equivalence groups such that the program is expected to behave the same with inputs from the same group

we can do this because we assume we dont have shit programmers like muzzi that hard code for inputs. So mistakes likely affect a whole class of input values

e,g. input must be a 4 digit so we split < > = 4
we have valid and invalid groups

Question 23

what is boundary testing

Answer 23

special case of equivalence testing where we test the boundary values of ranges.
e.g we code for mark between 0 and 100 but input like 101 cooks us.

Question 24

what is control flow testing

Answer 24

we draw flow graphs representing the logic of the code

nodes = statements
edges = transitions between statements

these graphs help us measure coverage

Question 25

what types of coverage can we measure with control flow testing

Answer 25

Statement coverage - every statement run at least once Edge coverage - every branch is traversed at least once Condition coverage - every condition tested with true or false at least once Path coverage - every distinct path through the program traversed at least once NB 100% statement coverage does not mean 100% edge coverage as we might have if statement. with it always true you get statement coverage but since not tested when false its not full edge coverage.

Question 26

What is state based testing

Answer 26

testing software by defining a set of abstract states and checking if it behaves as expected when changing between states components include: States - condition of object attributes Events - input given to system Actions - the output following an event Transitions - change in states Guard - condition associated with a even which determines if a transition is triggered or not

Question 27

types of state based coverage

Answer 27

event coverage - every event tested state coverage - every state visited action coverage - every action triggered

Question 28

what are control faults

Answer 28

refers to errors in control flow logic missing or incorrect transitions missing or incorrect actions sneak path - event is accepted when it shouldn't trap door - accepting undefined events deadlocks - permanent blocking of system

Question 29

How do we unit testing with regards to testing it in isolation

Answer 29

This is done by creating mock objects Test driver - simulates part of a system to invoke operation on the unit such as calling the function Test stub - simulates parts of the system that the unit needs to interact with.

Question 30

what's the convention for naming test cases

Answer 30

method name _ starting state _ expected result e.g. checkKey_anyState_invalidKeyRejected()

Question 31

what are assert statments

Answer 31

using in unit testing assertTrue(4 == (2 * 2)); assertEquals(expected, actual);

Question 32

What are the different types of Integration testing

Answer 32

Big bang Top down Bottom up Sandwich

Question 33

What is big bang integration testing and why we shouldn't dala

Answer 33

Where all units are linked at once and test Faults only identified after whole system is implemented might miss bugs and hard to isolate them hard to ensure all cases are tested

Question 34

What is bottom up testing

Answer 34

lowest level subsystems tested first and integrated components only tested once what it relies on is tested.

Question 35

Bottom up pros and cons

Answer 35

Pros: dont need stubs disjoint systems can be tested simultaneously lower level operations are usually critical to higher level ones so testing that first is usually a priority Cons: Drivers are needed Some higher level components like UI can be the source of many bugs and thus found late. if you have alot of lower level components, bottom up can almost seem like big bang

Question 36

what is top down testing

Answer 36

highest levels are tested first and work it way down

Question 37

Top down Pros and Cons

Answer 37

Pros: no need for drivers easier to write functional requirement test cases can deal with major design flaws earlier Cons: alot of stubs needed low level can only be tested once higher level are implemented

Question 38

What is sandwich testing

Answer 38

combination of top down and bottom up

Question 39

Sandwich Pros and Cons

Answer 39

Pros: low and high level tested simultaneously easier to test larger systems Cons: Can be expensive Need more devs, drivers and stubs Not suitable for systems with highly independent subsystems as this approach may force these parts to be tested together even tho they are not relevant to each other

Question 40

What is front end component testing

Answer 40

Involves testing components of UI like buttons, drop downs and other elements in ISOLATION.

Question 41

what type of testing does front-end component testing encompass

Answer 41

Unit Integration Snapshot - comparing rendered component output to detect UI changes End-to-End - testing whole app from user view Accessibility - people with disabilities Visual regression - detecting unintended visual changes Performance testing- responsiveness and efficiency Component Storybook - way to render and test UI features in isolation

Question 42

What is horizontal integration testing

Answer 42

focuses on testing layers of a system with new layers incrementally added to the last e.g. top down, bottom up, sandwich

Question 43

what is vertical integration testing

Answer 43

focuses on testing user stories, so testing components needs for a particular user story

Question 44

What is continuous integration

Answer 44

Continuous Integration (CI) is a software development practice where developers frequently integrate or add their code changes to a shared repository (usually multiple times a day). Builds and tests are automated to ensure it works

Question 45

what are types of quality testing

Answer 45

stress testing - bots to moer servers load volume testing - big data compatibility testing - older versions of software Timing testing - response time Security testing - attempt to hack recovery testing - responding to erros, lack of data, handling restarts and loadshedding cut offs etc.

Question 46

alpha vs beta testing

Answer 46

alpha is acceptance testing done in developer environment where beta is done in target environment.