[PATCH v3 1/2] kunit: Support for Parameterized Testing

From: Arpitha Raghunandan
Date: Mon Oct 26 2020 - 14:36:15 EST


Implementation of support for parameterized testing in KUnit.
This approach requires the creation of a test case using the
KUNIT_CASE_PARAM macro that accepts a generator function as input.
This generator function should return the next parameter given the
previous parameter in parameterized tests. It also provides
a macro to generate common-case generators.

Signed-off-by: Arpitha Raghunandan <98.arpi@xxxxxxxxx>
Co-developed-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
---
Changes v2->v3:
- Modifictaion of generator macro and method
Changes v1->v2:
- Use of a generator method to access test case parameters

include/kunit/test.h | 32 ++++++++++++++++++++++++++++++++
lib/kunit/test.c | 20 +++++++++++++++++++-
2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index a423fffefea0..16bf9f334e2c 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -142,6 +142,12 @@ struct kunit_case {
void (*run_case)(struct kunit *test);
const char *name;

+ /*
+ * Pointer to test parameter generator function.
+ * Used only for parameterized tests.
+ */
+ void* (*generate_params)(void *prev);
+
/* private: internal use only. */
bool success;
char *log;
@@ -162,6 +168,9 @@ static inline char *kunit_status_to_string(bool status)
* &struct kunit_case for an example on how to use it.
*/
#define KUNIT_CASE(test_name) { .run_case = test_name, .name = #test_name }
+#define KUNIT_CASE_PARAM(test_name, gen_params) \
+ { .run_case = test_name, .name = #test_name, \
+ .generate_params = gen_params }

/**
* struct kunit_suite - describes a related collection of &struct kunit_case
@@ -208,6 +217,15 @@ struct kunit {
const char *name; /* Read only after initialization! */
char *log; /* Points at case log after initialization */
struct kunit_try_catch try_catch;
+ /* param_values points to test case parameters in parameterized tests */
+ void *param_values;
+ /*
+ * current_param stores the index of the parameter in
+ * the array of parameters in parameterized tests.
+ * current_param + 1 is printed to indicate the parameter
+ * that causes the test to fail in case of test failure.
+ */
+ int current_param;
/*
* success starts as true, and may only be set to false during a
* test case; thus, it is safe to update this across multiple
@@ -1742,4 +1760,18 @@ do { \
fmt, \
##__VA_ARGS__)

+/**
+ * KUNIT_PARAM_GENERATOR() - Helper method for test parameter generators
+ * required in parameterized tests.
+ * @name: prefix of the name for the test parameter generator function.
+ * @prev: a pointer to the previous test parameter, NULL for first parameter.
+ * @array: a user-supplied pointer to an array of test parameters.
+ */
+#define KUNIT_PARAM_GENERATOR(name, array) \
+ static void *name##_gen_params(void *prev) \
+ { \
+ typeof((array)[0]) * __next = prev ? ((typeof(__next)) prev) + 1 : (array); \
+ return __next - (array) < ARRAY_SIZE((array)) ? __next : NULL; \
+ }
+
#endif /* _KUNIT_TEST_H */
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 750704abe89a..b70ab9b12f3b 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -127,6 +127,11 @@ unsigned int kunit_test_case_num(struct kunit_suite *suite,
}
EXPORT_SYMBOL_GPL(kunit_test_case_num);

+static void kunit_print_failed_param(struct kunit *test)
+{
+ kunit_err(test, "\n\tTest failed at parameter: %d\n", test->current_param + 1);
+}
+
static void kunit_print_string_stream(struct kunit *test,
struct string_stream *stream)
{
@@ -168,6 +173,8 @@ static void kunit_fail(struct kunit *test, struct kunit_assert *assert)
assert->format(assert, stream);

kunit_print_string_stream(test, stream);
+ if (test->param_values)
+ kunit_print_failed_param(test);

WARN_ON(string_stream_destroy(stream));
}
@@ -239,7 +246,18 @@ static void kunit_run_case_internal(struct kunit *test,
}
}

- test_case->run_case(test);
+ if (!test_case->generate_params) {
+ test_case->run_case(test);
+ } else {
+ test->param_values = test_case->generate_params(NULL);
+ test->current_param = 0;
+
+ while (test->param_values) {
+ test_case->run_case(test);
+ test->param_values = test_case->generate_params(test->param_values);
+ test->current_param++;
+ }
+ }
}

static void kunit_case_internal_cleanup(struct kunit *test)
--
2.25.1