Testing and Debugging

Question 1

How is test data designed?

Answer 1

Systematically

Question 2

What kind of process is debugging?

Answer 2

Lateral thinking

Question 3

What is testing?

Answer 3

Executing an implementation with dummy data

Question 4

What is a successful test?

Answer 4

One which shows an error

Question 5

A system has many...
A package has many...
A class has many ...

Answer 5

Packages
Classes
Methods

Question 6

What is top down testing?

Answer 6

Test each component before we test those it relies on. Write stubs for lower level components. Simultaneous with top down development. Design errors found early on

Question 7

What is bottom up testing?

Answer 7

Test each component before we test any that rely on it. We don’t have to write stubs. Cannot test incrementally with top down development

Question 8

What are test cases? What is test data?

Answer 8

Test cases are features we want to test. Test data is used to test them

Question 9

What is black box testing?

Answer 9

When we look only at the specification of the behaviour for the component in order to construct test cases and data

Question 10

What is white box testing? (Glass box testing)

Answer 10

When we also look at the implementation of the component when we construct the test data

Question 11

What is equivalence partitioning?

Answer 11

A technique for constructing test data from the specification (only) of the component. We partition the set of all possible input data into classifications with common properties. We do the same for output data. We identify these classifications as test cases. We choose representative values from the test cases to be used as test data

Question 12

What is structural testing?

Answer 12

A technique for constructing test data by looking at the implementation code
Choose data so that every combination of every path through the code is tried
Good technique for checking against many simple run time errors

Question 13

Which testing approach is best?

Answer 13

Equivalence partitioning at first adding extra cases from structural testing

Question 14

What is symbolic execution?

Answer 14

A symbolic execution covers an infinite number of sets of data. A finite number of symbolic executions is needed to cover all data

Question 15

What are the two parts of debugging?

Answer 15

Error location and error elimination

Question 16

What are some common errors?

Answer 16

Implicit type casting problems
starting a counter from 1 instead of 0
failing to update an array index
updating array index too early/late
failing to initialise a variable value
variable scope

Question 17

What is a workaround?

Answer 17

A quick fix

Anti-bug: fix the symptom not the cause