Currently, given something (fairly dystopian) like
KUNIT_EXPECT_EQ(test, 2 + 2, 5)
KUnit will prints a failure message like this.
Expected 2 + 2 == 5, but 2 + 2 == 4 5 == 5
With this patch, the output just becomes
Expected 2 + 2 == 5, but 2 + 2 == 4
This patch is slightly hacky, but it's quite common* to compare an expression to a literal integer value, so this can make KUnit less chatty in many cases. (This patch also fixes variants like KUNIT_EXPECT_GT, LE, et al.).
It also allocates an additional string briefly, but given this only happens on test failures, it doesn't seem too bad a tradeoff. Also, in most cases it'll realize the lengths are unequal and bail out before the allocation.
We could save the result of the formatted string to avoid wasting this extra work, but it felt cleaner to leave it as-is.
Edge case: for something silly and unrealistic like
KUNIT_EXPECT_EQ(test, 4, 5);
It'll generate this message with a trailing "but"
Expected 4 == 5, but
<next line of normal output>
It didn't feel worth adding a check up-front to see if both sides are literals to handle this better.
*A quick grep suggests 100+ comparisons to an integer literal as the right hand side.
Signed-off-by: Daniel Latypov dlatypov@google.com Tested-by: David Gow davidgow@google.com Reviewed-by: Brendan Higgins brendanhiggins@google.com --- lib/kunit/assert.c | 39 +++++++++++++++++++++++++++++++++------ 1 file changed, 33 insertions(+), 6 deletions(-)
diff --git a/lib/kunit/assert.c b/lib/kunit/assert.c index 33acdaa28a7d..e0ec7d6fed6f 100644 --- a/lib/kunit/assert.c +++ b/lib/kunit/assert.c @@ -85,6 +85,29 @@ void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert, } EXPORT_SYMBOL_GPL(kunit_ptr_not_err_assert_format);
+/* Checks if `text` is a literal representing `value`, e.g. "5" and 5 */ +static bool is_literal(struct kunit *test, const char *text, long long value, + gfp_t gfp) +{ + char *buffer; + int len; + bool ret; + + len = snprintf(NULL, 0, "%lld", value); + if (strlen(text) != len) + return false; + + buffer = kunit_kmalloc(test, len+1, gfp); + if (!buffer) + return false; + + snprintf(buffer, len+1, "%lld", value); + ret = strncmp(buffer, text, len) == 0; + + kunit_kfree(test, buffer); + return ret; +} + void kunit_binary_assert_format(const struct kunit_assert *assert, struct string_stream *stream) { @@ -97,12 +120,16 @@ void kunit_binary_assert_format(const struct kunit_assert *assert, binary_assert->left_text, binary_assert->operation, binary_assert->right_text); - string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld\n", - binary_assert->left_text, - binary_assert->left_value); - string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld", - binary_assert->right_text, - binary_assert->right_value); + if (!is_literal(stream->test, binary_assert->left_text, + binary_assert->left_value, stream->gfp)) + string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld\n", + binary_assert->left_text, + binary_assert->left_value); + if (!is_literal(stream->test, binary_assert->right_text, + binary_assert->right_value, stream->gfp)) + string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld", + binary_assert->right_text, + binary_assert->right_value); kunit_assert_print_msg(assert, stream); } EXPORT_SYMBOL_GPL(kunit_binary_assert_format);
base-commit: 1e0d27fce010b0a4a9e595506b6ede75934c31be