|
|
Definition of terms
|
|
|
===================
|
|
|
|
|
|
This section defines the terms used in this document and correlates them with
|
|
|
what is currently used on QEMU.
|
|
|
|
|
|
Automated tests
|
|
|
---------------
|
|
|
|
|
|
An automated test is written on a test framework using its generic test
|
|
|
functions/classes. The test framework can run the tests and report their
|
|
|
success or failure [1]_.
|
|
|
|
|
|
An automated test has essentially three parts:
|
|
|
|
|
|
1. The test initialization of the parameters, where the expected parameters,
|
|
|
like inputs and expected results, are set up;
|
|
|
2. The call to the code that should be tested;
|
|
|
3. An assertion, comparing the result from the previous call with the expected
|
|
|
result set during the initialization of the parameters. If the result
|
|
|
matches the expected result, the test has been successful; otherwise, it has
|
|
|
failed.
|
|
|
|
|
|
Unit testing
|
|
|
------------
|
|
|
|
|
|
A unit test is responsible for exercising individual software components as a
|
|
|
unit, like interfaces, data structures, and functionality, uncovering errors
|
|
|
within the boundaries of a component. The verification effort is in the
|
|
|
smallest software unit and focuses on the internal processing logic and data
|
|
|
structures. A test case of unit tests should be designed to uncover errors due
|
|
|
to erroneous computations, incorrect comparisons, or improper control flow [2]_.
|
|
|
|
|
|
On QEMU, unit testing is represented by the 'check-unit' target from 'make'.
|
|
|
|
|
|
Functional testing
|
|
|
------------------
|
|
|
|
|
|
A functional test focuses on the functional requirement of the software.
|
|
|
Deriving sets of input conditions, the functional tests should fully exercise
|
|
|
all the functional requirements for a program. Functional testing is
|
|
|
complementary to other testing techniques, attempting to find errors like
|
|
|
incorrect or missing functions, interface errors, behavior errors, and
|
|
|
initialization and termination errors [3]_.
|
|
|
|
|
|
On QEMU, functional testing is represented by the 'check-qtest' target from
|
|
|
'make'.
|
|
|
|
|
|
System testing
|
|
|
--------------
|
|
|
|
|
|
System tests ensure all application elements mesh properly while the overall
|
|
|
functionality and performance are achieved [4]_. Some or all system components
|
|
|
are integrated to create a complete system to be tested as a whole. System
|
|
|
testing ensures that components are compatible, interact correctly, and
|
|
|
transfer the right data at the right time across their interfaces. As system
|
|
|
testing focuses on interactions, use case-based testing is a practical approach
|
|
|
to system testing [5]_. Note that, in some cases, system testing may require
|
|
|
interaction with third-party software, like operating system images, databases,
|
|
|
networks, and so on.
|
|
|
|
|
|
On QEMU, system testing is represented by the 'check-avocado' target from
|
|
|
'make'.
|
|
|
|
|
|
Flaky tests
|
|
|
-----------
|
|
|
|
|
|
A flaky test is defined as a test that exhibits both a passing and a failing
|
|
|
result with the same code on different runs. Some usual reasons for an
|
|
|
intermittent/flaky test are async wait, concurrency, and test order dependency
|
|
|
[6]_.
|
|
|
|
|
|
Gating
|
|
|
------
|
|
|
|
|
|
A gate restricts the move of code from one stage to another on a
|
|
|
test/deployment pipeline. The step move is granted with approval. The approval
|
|
|
can be a manual intervention or a set of tests succeeding [7]_.
|
|
|
|
|
|
On QEMU, the gating process happens during the pull request. The approval is
|
|
|
done by the project leader running its own set of tests. The pull request gets
|
|
|
merged when the tests succeed.
|
|
|
|
|
|
Continuous Integration (CI)
|
|
|
---------------------------
|
|
|
|
|
|
Continuous integration (CI) requires the builds of the entire application and
|
|
|
the execution of a comprehensive set of automated tests every time there is a
|
|
|
need to commit any set of changes [8]_. The automated tests can be composed of
|
|
|
the unit, functional, system, and other tests.
|
|
|
|
|
|
Keynotes about continuous integration (CI) [9]_:
|
|
|
|
|
|
1. System tests may depend on external software (operating system images,
|
|
|
firmware, database, network).
|
|
|
2. It may take a long time to build and test. It may be impractical to build
|
|
|
the system being developed several times per day.
|
|
|
3. If the development platform is different from the target platform, it may
|
|
|
not be possible to run system tests in the developer’s private workspace.
|
|
|
There may be differences in hardware, operating system, or installed
|
|
|
software. Therefore, more time is required for testing the system.
|
|
|
|
|
|
References
|
|
|
----------
|
|
|
|
|
|
.. [1] Sommerville, Ian (2016). Software Engineering. p. 233.
|
|
|
.. [2] Pressman, Roger S. & Maxim, Bruce R. (2020). Software Engineering,
|
|
|
A Practitioner’s Approach. p. 48, 376, 378, 381.
|
|
|
.. [3] Pressman, Roger S. & Maxim, Bruce R. (2020). Software Engineering,
|
|
|
A Practitioner’s Approach. p. 388.
|
|
|
.. [4] Pressman, Roger S. & Maxim, Bruce R. (2020). Software Engineering,
|
|
|
A Practitioner’s Approach. Software Engineering, p. 377.
|
|
|
.. [5] Sommerville, Ian (2016). Software Engineering. p. 59, 232, 240.
|
|
|
.. [6] Luo, Qingzhou, et al. An empirical analysis of flaky tests.
|
|
|
Proceedings of the 22nd ACM SIGSOFT International Symposium on
|
|
|
Foundations of Software Engineering. 2014.
|
|
|
.. [7] Humble, Jez & Farley, David (2010). Continuous Delivery:
|
|
|
Reliable Software Releases Through Build, Test, and Deployment, p. 122.
|
|
|
.. [8] Humble, Jez & Farley, David (2010). Continuous Delivery:
|
|
|
Reliable Software Releases Through Build, Test, and Deployment, p. 55.
|
|
|
.. [9] Sommerville, Ian (2016). Software Engineering. p. 743.
|