Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue,  8 Nov 2022 16:36:17 -0800
In-Reply-To: <20221109003618.3784591-1-dlatypov@google.com>
Mime-Version: 1.0
References: <20221109003618.3784591-1-dlatypov@google.com>
Message-ID: <20221109003618.3784591-2-dlatypov@google.com>
Subject: [PATCH v2 2/3] Documentation: KUnit: reword description of assertions
From:   Daniel Latypov <dlatypov@google.com>
To:     brendanhiggins@google.com, davidgow@google.com
Cc:     rmoar@google.com, linux-kernel@vger.kernel.org,
        kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org,
        linux-doc@vger.kernel.org, skhan@linuxfoundation.org,
        Daniel Latypov <dlatypov@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

The existing wording implies that kunit_kmalloc_array() is "the method
under test". We're actually testing the sort() function in that example.
This is because the example was changed in commit 953574390634
("Documentation: KUnit: Rework writing page to focus on writing tests"),
but the wording was not.

Also add a `note` telling people they can use the KUNIT_ASSERT_EQ()
macros from any function. Some users might be coming from a framework
like gUnit where that'll compile but silently do the wrong thing.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
---
 Documentation/dev-tools/kunit/usage.rst | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index b0a6c3bc0eeb..8060114e3aa6 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -112,11 +112,14 @@ terminates the test case if the condition is not satisfied. For example:
 			KUNIT_EXPECT_LE(test, a[i], a[i + 1]);
 	}
 
-In this example, the method under test should return pointer to a value. If the
-pointer returns null or an errno, we want to stop the test since the following
-expectation could crash the test case. `ASSERT_NOT_ERR_OR_NULL(...)` allows us
-to bail out of the test case if the appropriate conditions are not satisfied to
-complete the test.
+In this example, we need to be able to allocate an array to test the ``sort()``
+function. So we use ``KUNIT_ASSERT_NOT_ERR_OR_NULL()`` to abort the test if
+we there's an allocation error.
+
+.. note::
+   In other test frameworks, ``ASSERT`` macros are often implemented by calling
+   ``return`` so they only work from the test function. In KUnit, we stop the
+   current kthread on failure, so you can call them from anywhere.
 
 Customizing error messages
 --------------------------
-- 
2.38.1.431.g37b22c650d-goog