| Message ID | 20190824013425.175645-1-brendanhiggins@google.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | kunit: introduce KUnit, the Linux kernel unit testing framework | expand |
On 8/23/19 7:34 PM, Brendan Higgins wrote: > ## TL;DR > > This revision addresses comments from Shuah by fixing a couple > checkpatch warnings and fixing some comment readability issues. No API > or major structual changes have been made since v13. > > ## Background > > This patch set proposes KUnit, a lightweight unit testing and mocking > framework for the Linux kernel. > > Unlike Autotest and kselftest, KUnit is a true unit testing framework; > it does not require installing the kernel on a test machine or in a VM > (however, KUnit still allows you to run tests on test machines or in VMs > if you want[1]) and does not require tests to be written in userspace > running on a host kernel. Additionally, KUnit is fast: From invocation > to completion KUnit can run several dozen tests in about a second. > Currently, the entire KUnit test suite for KUnit runs in under a second > from the initial invocation (build time excluded). > > KUnit is heavily inspired by JUnit, Python's unittest.mock, and > Googletest/Googlemock for C++. KUnit provides facilities for defining > unit test cases, grouping related test cases into test suites, providing > common infrastructure for running tests, mocking, spying, and much more. > > ### What's so special about unit testing? > > A unit test is supposed to test a single unit of code in isolation, > hence the name. There should be no dependencies outside the control of > the test; this means no external dependencies, which makes tests orders > of magnitudes faster. Likewise, since there are no external dependencies, > there are no hoops to jump through to run the tests. Additionally, this > makes unit tests deterministic: a failing unit test always indicates a > problem. Finally, because unit tests necessarily have finer granularity, > they are able to test all code paths easily solving the classic problem > of difficulty in exercising error handling code. > > ### Is KUnit trying to replace other testing frameworks for the kernel? > > No. Most existing tests for the Linux kernel are end-to-end tests, which > have their place. A well tested system has lots of unit tests, a > reasonable number of integration tests, and some end-to-end tests. KUnit > is just trying to address the unit test space which is currently not > being addressed. > > ### More information on KUnit > > There is a bunch of documentation near the end of this patch set that > describes how to use KUnit and best practices for writing unit tests. > For convenience I am hosting the compiled docs here[2]. > > Additionally for convenience, I have applied these patches to a > branch[3]. The repo may be cloned with: > git clone https://kunit.googlesource.com/linux > This patchset is on the kunit/rfc/v5.3/v15 branch. > > ## Changes Since Last Version > > - Moved comment from inline in macro to kernel-doc to address checkpatch > warning. > - Demoted BUG() to WARN_ON. > - Formatted some kernel-doc comments to make them more readible. > > [1] https://google.github.io/kunit-docs/third_party/kernel/docs/usage.html#kunit-on-non-uml-architectures > [2] https://google.github.io/kunit-docs/third_party/kernel/docs/ > [3] https://kunit.googlesource.com/linux/+/kunit/rfc/v5.3/v15 > Hi Brendan, Thanks for doing this work. Thanks for accommodating my request to improve the document/comment blocks in patch 01 and removing BUG() from patch 09. The comment block reads well now. Applied the series to linux-kselftest next for 5.4-rc1. thanks, -- Shuah