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* [PATCH v3 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework
@ 2019-05-14  5:42 Brendan Higgins
  2019-05-14  5:42 ` [PATCH v3 01/18] kunit: test: add KUnit test runner core Brendan Higgins
                   ` (17 more replies)
  0 siblings, 18 replies; 28+ messages in thread
From: Brendan Higgins @ 2019-05-14  5:42 UTC (permalink / raw)
  To: frowand.list, gregkh, keescook, kieran.bingham, mcgrof, robh,
	sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	dan.j.williams, daniel, jdike, joel, julia.lawall, khilman,
	knut.omang, logang, mpe, pmladek, rdunlap, richard, rientjes,
	rostedt, wfg, Brendan Higgins

## TLDR

I mostly wanted to incorporate feedback I got over the last week and a
half.

Biggest things to look out for:

- KUnit core now outputs results in TAP14.
- Heavily reworked tools/testing/kunit/kunit.py
  - Changed how parsing works.
  - Added testing.
  - Greg, Logan, you might want to re-review this.
- Added documentation on how to use KUnit on non-UML kernels. You can
  see the docs rendered here[1].

There is still some discussion going on on the [PATCH v2 00/17] thread,
but I wanted to get some of these updates out before they got too stale
(and too difficult for me to keep track of). I hope no one minds.

## 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) 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 under 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/v5.1/v3 branch.

## Changes Since Last Version

- Converted KUnit core to print test results in TAP14 format as
  suggested by Greg and Frank.
- Heavily reworked tools/testing/kunit/kunit.py
  - Changed how parsing works.
  - Added testing.
- Added documentation on how to use KUnit on non-UML kernels. You can
  see the docs rendered here[1].
- Added a new set of EXPECTs and ASSERTs for pointer comparison.
- Removed more function indirection as suggested by Logan.
- Added a new patch that adds `kunit_try_catch_throw` to objtool's
  noreturn list.
- Fixed a number of minorish issues pointed out by Shuah, Masahiro, and
  kbuild bot.

[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/v5.1/v3

-- 
2.21.0.1020.gf2820cf01a-goog


^ permalink raw reply	[flat|nested] 28+ messages in thread

end of thread, other threads:[~2019-05-15 13:45 UTC | newest]

Thread overview: 28+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-14  5:42 [PATCH v3 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 01/18] kunit: test: add KUnit test runner core Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 02/18] kunit: test: add test resource management API Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 03/18] kunit: test: add string_stream a std::stream like string builder Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 04/18] kunit: test: add kunit_stream a std::stream like logger Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 05/18] kunit: test: add the concept of expectations Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 06/18] kbuild: enable building KUnit Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 07/18] kunit: test: add initial tests Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 08/18] objtool: add kunit_try_catch_throw to the noreturn list Brendan Higgins
2019-05-14  6:56   ` Peter Zijlstra
2019-05-14  8:12     ` Brendan Higgins
2019-05-14  8:46       ` Peter Zijlstra
2019-05-14 18:12         ` Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 09/18] kunit: test: add support for test abort Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 10/18] kunit: test: add tests for kunit " Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 11/18] kunit: test: add the concept of assertions Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 12/18] kunit: test: add tests for KUnit managed resources Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 13/18] kunit: tool: add Python wrappers for running KUnit tests Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 14/18] kunit: defconfig: add defconfigs for building " Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 15/18] Documentation: kunit: add documentation for KUnit Brendan Higgins
2019-05-14 13:34   ` Jonathan Corbet
2019-05-14 18:08     ` Brendan Higgins
2019-05-14 18:16       ` Jonathan Corbet
2019-05-14 23:19         ` Brendan Higgins
2019-05-15 13:45           ` Jonathan Corbet
2019-05-14  5:42 ` [PATCH v3 16/18] MAINTAINERS: add entry for KUnit the unit testing framework Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() Brendan Higgins
2019-05-14  5:42 ` [PATCH v3 18/18] MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section Brendan Higgins

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