[Linux-kernel-mentees] [RFC v2 1/2] kunit: Support for Parameterized Testing

[Arpitha Raghunandan]

This patch has a basic implementation for adding support for
parameterized testing in KUnit. The macro KUNIT_CASE_PARAM takes
in a function pointer to a function that returns the test case
parameters, the number of test cases and the size of each test 
case parameter. The get_test_case_parameters() acts as an iterator
and returns one test case parameter each time it is called.


Signed-off-by: Arpitha Raghunandan <98.arpi at gmail.com>
---
Changes v1->v2:
- Parameterized input stored in a void* array
- An iterator method to access the different parameters

 include/kunit/test.h | 17 +++++++++++++++++
 lib/kunit/test.c     | 27 +++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 59f3144f009a..d037ba8c3002 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -140,10 +140,14 @@ struct kunit;
 struct kunit_case {
 	void (*run_case)(struct kunit *test);
 	const char *name;
+	void* (*get_params)(void);
+	int max_parameters_count;
+	int parameter_size;
 
 	/* private: internal use only. */
 	bool success;
 	char *log;
+	bool parameterized;
 };
 
 static inline char *kunit_status_to_string(bool status)
@@ -162,6 +166,11 @@ static inline char *kunit_status_to_string(bool status)
  */
 #define KUNIT_CASE(test_name) { .run_case = test_name, .name = #test_name }
 
+#define KUNIT_CASE_PARAM(test_name, getparams, count, size) {	.run_case = test_name,						\
+								.name = #test_name, .parameterized = true,			\
+								.get_params = (void* (*)(void))getparams,			\
+								.max_parameters_count = count, .parameter_size = size }
+
 /**
  * struct kunit_suite - describes a related collection of &struct kunit_case
  *
@@ -206,6 +215,11 @@ struct kunit {
 	/* private: internal use only. */
 	const char *name; /* Read only after initialization! */
 	char *log; /* Points at case log after initialization */
+	bool parameterized; /* True for parameterized tests */
+	void *param_values; /* Stores the test parameters for parameterized tests */
+	int max_parameters_count; /* Indicates maximum number of parameters for parameterized tests */
+	int iterator_count; /* Used by the iterator method for parameterized tests */
+	int parameter_size; /* Indicates size of a single test case for parameterized tests */
 	struct kunit_try_catch try_catch;
 	/*
 	 * success starts as true, and may only be set to false during a
@@ -225,6 +239,7 @@ struct kunit {
 };
 
 void kunit_init_test(struct kunit *test, const char *name, char *log);
+void kunit_init_param_test(struct kunit *test, struct kunit_case *test_case);
 
 int kunit_run_tests(struct kunit_suite *suite);
 
@@ -237,6 +252,8 @@ int __kunit_test_suites_init(struct kunit_suite **suites);
 
 void __kunit_test_suites_exit(struct kunit_suite **suites);
 
+void *get_test_case_parameters(struct kunit *test);
+
 /**
  * kunit_test_suites() - used to register one or more &struct kunit_suite
  *			 with KUnit.
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index c36037200310..c4fd8f729e96 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -236,6 +236,18 @@ void kunit_init_test(struct kunit *test, const char *name, char *log)
 }
 EXPORT_SYMBOL_GPL(kunit_init_test);
 
+void kunit_init_param_test(struct kunit *test, struct kunit_case *test_case)
+{
+	spin_lock_init(&test->lock);
+	INIT_LIST_HEAD(&test->resources);
+	test->parameterized = true;
+	test->param_values = (void *)(test_case->get_params());
+	test->max_parameters_count = test_case->max_parameters_count;
+	test->parameter_size = test_case->parameter_size;
+	test->iterator_count = 0;
+}
+EXPORT_SYMBOL_GPL(kunit_init_param_test);
+
 /*
  * Initializes and runs test case. Does not clean up or do post validations.
  */
@@ -343,6 +355,8 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite,
 	struct kunit test;
 
 	kunit_init_test(&test, test_case->name, test_case->log);
+	if (test_case->parameterized)
+		kunit_init_param_test(&test, test_case);
 	try_catch = &test.try_catch;
 
 	kunit_try_catch_init(try_catch,
@@ -407,6 +421,19 @@ void __kunit_test_suites_exit(struct kunit_suite **suites)
 }
 EXPORT_SYMBOL_GPL(__kunit_test_suites_exit);
 
+/*
+ * Iterator method for the parameterized test cases
+ */
+void *get_test_case_parameters(struct kunit *test)
+{
+	int index = test->iterator_count * test->parameter_size;
+
+	if (test->iterator_count != test->max_parameters_count)
+		test->iterator_count++;
+	return (test->param_values + index);
+}
+EXPORT_SYMBOL_GPL(get_test_case_parameters);
+
 /*
  * Used for static resources and when a kunit_resource * has been created by
  * kunit_alloc_resource().  When an init function is supplied, @data is passed
-- 
2.25.1