06 Testability

Question 1

Developer

Answer 1

A person whose primary responsibility is to write source code

Question 2

Quality Assurance

Answer 2

To ensure that few, if any, defects remain in the software when it is delievered to its customers or released to the market.

Question 3

Testing (Operational)

Answer 3

The execution of software and the observation of its behavior or outcome demonstrated using controlled experiments

Question 4

Testing (Operational) Purpose

Answer 4

To demonstrate quality/ proper behavior.
To detect problems that need to be fixed.

Question 5

Defects/Bugs Types

Answer 5

Errors
Fault
Failure
Bugs

Question 6

Error:

Answer 6

A mistake made by a programmer or SE which caused the fault which in turn may cause a failure.
- Conceptual mistake.
- Human misunderstanding

Question 7

Fault

Answer 7

Condition/Internal characteristic that may cause a failure in the system.

Question 8

Failure

Answer 8

Inability of the system to perform a function according to its specification due to some fault.
- Deviation from expected behavior
- Something goes wrong at execution.

Question 9

Relationship of Defects

Answer 9

Errors can cause Faults.
Faults can cause Failures.

Question 10

Testability

Answer 10

The degree to which a system or component facilitates the establishment of test criteria and the performance of tests to determine whether those criteria have been met.

How hard it is to find faults

Question 11

Testability is dominated by two practical problems

Answer 11

How to provide the test values to the software
How to observe the results of tese execution.

Question 12

Testability is linked to our:

Answer 12

Prior experience.

Question 13

The more testable the software

Answer 13

The greater the chance that somebody will test it

Question 14

Testability Benefits

Answer 14

If the software is developed so that its behavior can be verified, it’s easy to confirm that it supports a certain features.

Fewer Suprises.

More easily changed (Fear results in duplication of defects)

Question 15

When a program element is testable, it means

Answer 15

That it can be put in a known state, acted on, and then observed.
Can be done without affecting or interfering any other program elements.

Question 16

What are hiding often at odds with each other?

Answer 16

Observability and Information

Question 17

Controllability :: Isolability

Answer 17

The ability to put something in a specific state.
Is important to testing because it leads to reproducibility.

The abiility to reproduce a given condition depends on the ability to isolate it and manipulate its internal state.

Components with lots of dependencies are diffcult to modify and test.

Question 18

Controllability :: Deployability

Answer 18

Is a measure of the amount of work needed to deploy the system into production.

Affects the developer’s ability to run their code in a production-like environment.

Question 19

Smallness

Answer 19

The smaller the software, the better the testability.

Broken up into:
1. Singularity
2. Efficiency
3. Level of Abstraction
4. Reuse.

Question 20

Correctness Definitions:

Answer 20

In Traditional Methods, correct behavior is defined completely at the beginning.

In Agile Methods, One way to redefine correctness is to be relative to a specific set of tests.

Question 21

Test Harnesses

Answer 21

Are automated.
Include a test oracle that can evaluate whether that test executed correctly.
Server as a specification of requirements.
Must be high quality and must run quickly
Run every time we make changes.

Question 22

Continuous Integration

Answer 22

A software engineering process where isolated code changes are immediately tested and reported on as they are added to a larger codebase.

Provide rapid feedback to identify and correct defects as soon as they are introduced.

Enable automation.