From patchwork Wed Nov 28 19:36:17 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Higgins X-Patchwork-Id: 10703209 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E39015A8 for ; Wed, 28 Nov 2018 19:37:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B9312B182 for ; Wed, 28 Nov 2018 19:37:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7D8AB2B6BD; Wed, 28 Nov 2018 19:37:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 041C92DC56 for ; Wed, 28 Nov 2018 19:37:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726737AbeK2Gj4 (ORCPT ); Thu, 29 Nov 2018 01:39:56 -0500 Received: from mail-qk1-f201.google.com ([209.85.222.201]:47978 "EHLO mail-qk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726283AbeK2Gj4 (ORCPT ); Thu, 29 Nov 2018 01:39:56 -0500 Received: by mail-qk1-f201.google.com with SMTP id z68so27679990qkb.14 for ; Wed, 28 Nov 2018 11:37:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=99nVbqfKL8VgOyeZOYLd9fGPS1EwErpNGV1fQd8c1qI=; b=sY3yGXUB7UeexaSMFHiqXwQqWJc1kjASLGdzGosIcyV73/cIl5rC3ujnaaFiogt+qr 3UE0kqZrHe4N0ZtFk/g86WTYoPDbzISqGuduMrCxPQwcp5oXsOu032M3QYhSlkD2IzRM TnlBclywIp4pcV6BZG0eZh1pFbgKpOhPIVc6DS8FUrhoeCIJFCt8JEPCwtviX2ht06z/ 9+mzN2WmSwCSedYDp3xYEWab6D3TeVKlxQSvba8+nnsvOP5NYDb3usBmFA4lHcOxbI2b uFGVzNcSo+M+swI0AtqlEZDDIHixe4xlolsVlF1r81+Naprqiegt/QdNILlqOCQoHtDn JNkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=99nVbqfKL8VgOyeZOYLd9fGPS1EwErpNGV1fQd8c1qI=; b=I1BVMy4ruRmaam95EqjRuf0d1RXo/oCcoMmyHSqNAPrzYGJpssXevMXYGJtNYOPI9P 8OqEXsdVEXqtNzIL+PaK31YvQsIPrF31TcqMwwKVWoD6NydeV2CNTqrunzB6/7LNkxzG KlxsY9WBihCBav05rGIhXHUbAFYtLvEFu2Rl5xe9qGHi+pJBMzufdQEuXIBiDJzQqQLg iaDftS2VnWF9w5q0DDZ5RgsW2CjB57ngY+i4xKxgTnUom4wkXJt4+s2o0AtZuDgo2Sem uwzCelYv2P7uF3C4djmGZRWSP2czfZKf8gHeq4ZTm9BeOodCF5xdceQicKUDFniDZ7PN MnJw== X-Gm-Message-State: AA+aEWYM2ZaozpfNMh9c9trDQHEae23tGStb15iyT3rpQVpyqduvSaO/ tBqlPTYmv27sccpbKngKmfGPef4YgNRTvLWg6cS4dA== X-Google-Smtp-Source: AFSGD/VCWycCbDmFp6Z5qNxzgmexxk1/jZS8YbUaoMOmSU6YkTfkM2zG1R/OjWIDtfLq/fQe62iAC1tOjqPaVFw87UApQA== X-Received: by 2002:ac8:7244:: with SMTP id l4mr4486112qtp.21.1543433831218; Wed, 28 Nov 2018 11:37:11 -0800 (PST) Date: Wed, 28 Nov 2018 11:36:17 -0800 Message-Id: <20181128193636.254378-1-brendanhiggins@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.20.0.rc0.387.gc7a69e6b6c-goog Subject: [RFC v3 00/19] kunit: introduce KUnit, the Linux kernel unit testing framework From: Brendan Higgins To: gregkh@linuxfoundation.org, keescook@google.com, mcgrof@kernel.org, shuah@kernel.org Cc: joel@jms.id.au, mpe@ellerman.id.au, joe@perches.com, brakmo@fb.com, rostedt@goodmis.org, Tim.Bird@sony.com, khilman@baylibre.com, julia.lawall@lip6.fr, linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, jdike@addtoit.com, richard@nod.at, linux-um@lists.infradead.org, daniel@ffwll.ch, dri-devel@lists.freedesktop.org, robh@kernel.org, dan.j.williams@intel.com, linux-nvdimm@lists.01.org, kieran.bingham@ideasonboard.com, frowand.list@gmail.com, knut.omang@oracle.com, Brendan Higgins Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 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: https://google.github.io/kunit-docs/third_party/kernel/docs/ Additionally for convenience, I have applied these patches to a branch: https://kunit.googlesource.com/linux/+/kunit/rfc/4.19/v3 The repo may be cloned with: git clone https://kunit.googlesource.com/linux This patchset is on the kunit/rfc/4.19/v3 branch. ## Changes Since Last Version - Changed namespace prefix from `test_*` to `kunit_*` as requested by Shuah. - Started converting/cleaning up the device tree unittest to use KUnit. - Started adding KUnit expectations with custom messages.