path: root/include/kunit/test.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Base unit test (KUnit) API.
 *
 * Copyright (C) 2019, Google LLC.
 * Author: Brendan Higgins <brendanhiggins@google.com>
 */

#ifndef _KUNIT_TEST_H
#define _KUNIT_TEST_H

#include <kunit/assert.h>
#include <kunit/try-catch.h>

#include <linux/compiler.h>
#include <linux/container_of.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kconfig.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>

#include <asm/rwonce.h>

struct kunit_resource;

typedef int (*kunit_resource_init_t)(struct kunit_resource *, void *);
typedef void (*kunit_resource_free_t)(struct kunit_resource *);

/**
 * struct kunit_resource - represents a *test managed resource*
 * @data: for the user to store arbitrary data.
 * @name: optional name
 * @free: a user supplied function to free the resource. Populated by
 * kunit_resource_alloc().
 *
 * Represents a *test managed resource*, a resource which will automatically be
 * cleaned up at the end of a test case.
 *
 * Resources are reference counted so if a resource is retrieved via
 * kunit_alloc_and_get_resource() or kunit_find_resource(), we need
 * to call kunit_put_resource() to reduce the resource reference count
 * when finished with it.  Note that kunit_alloc_resource() does not require a
 * kunit_resource_put() because it does not retrieve the resource itself.
 *
 * Example:
 *
 * .. code-block:: c
 *
 *	struct kunit_kmalloc_params {
 *		size_t size;
 *		gfp_t gfp;
 *	};
 *
 *	static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
 *	{
 *		struct kunit_kmalloc_params *params = context;
 *		res->data = kmalloc(params->size, params->gfp);
 *
 *		if (!res->data)
 *			return -ENOMEM;
 *
 *		return 0;
 *	}
 *
 *	static void kunit_kmalloc_free(struct kunit_resource *res)
 *	{
 *		kfree(res->data);
 *	}
 *
 *	void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
 *	{
 *		struct kunit_kmalloc_params params;
 *
 *		params.size = size;
 *		params.gfp = gfp;
 *
 *		return kunit_alloc_resource(test, kunit_kmalloc_init,
 *			kunit_kmalloc_free, &params);
 *	}
 *
 * Resources can also be named, with lookup/removal done on a name
 * basis also.  kunit_add_named_resource(), kunit_find_named_resource()
 * and kunit_destroy_named_resource().  Resource names must be
 * unique within the test instance.
 */
struct kunit_resource {
	void *data;
	const char *name;
	kunit_resource_free_t free;

	/* private: internal use only. */
	struct kref refcount;
	struct list_head node;
};

struct kunit;

/* Size of log associated with test. */
#define KUNIT_LOG_SIZE	512

/* Maximum size of parameter description string. */
#define KUNIT_PARAM_DESC_SIZE 128

/* Maximum size of a status comment. */
#define KUNIT_STATUS_COMMENT_SIZE 256

/*
 * TAP specifies subtest stream indentation of 4 spaces, 8 spaces for a
 * sub-subtest.  See the "Subtests" section in
 * https://node-tap.org/tap-protocol/
 */
#define KUNIT_SUBTEST_INDENT		"    "
#define KUNIT_SUBSUBTEST_INDENT		"        "

/**
 * enum kunit_status - Type of result for a test or test suite
 * @KUNIT_SUCCESS: Denotes the test suite has not failed nor been skipped
 * @KUNIT_FAILURE: Denotes the test has failed.
 * @KUNIT_SKIPPED: Denotes the test has been skipped.
 */
enum kunit_status {
	KUNIT_SUCCESS,
	KUNIT_FAILURE,
	KUNIT_SKIPPED,
};

/**
 * struct kunit_case - represents an individual test case.
 *
 * @run_case: the function representing the actual test case.
 * @name:     the name of the test case.
 * @generate_params: the generator function for parameterized tests.
 *
 * A test case is a function with the signature,
 * ``void (*)(struct kunit *)``
 * that makes expectations and assertions (see KUNIT_EXPECT_TRUE() and
 * KUNIT_ASSERT_TRUE()) about code under test. Each test case is associated
 * with a &struct kunit_suite and will be run after the suite's init
 * function and followed by the suite's exit function.
 *
 * A test case should be static and should only be created with the
 * KUNIT_CASE() macro; additionally, every array of test cases should be
 * terminated with an empty test case.
 *
 * Example:
 *
 * .. code-block:: c
 *
 *	void add_test_basic(struct kunit *test)
 *	{
 *		KUNIT_EXPECT_EQ(test, 1, add(1, 0));
 *		KUNIT_EXPECT_EQ(test, 2, add(1, 1));
 *		KUNIT_EXPECT_EQ(test, 0, add(-1, 1));
 *		KUNIT_EXPECT_EQ(test, INT_MAX, add(0, INT_MAX));
 *		KUNIT_EXPECT_EQ(test, -1, add(INT_MAX, INT_MIN));
 *	}
 *
 *	static struct kunit_case example_test_cases[] = {
 *		KUNIT_CASE(add_test_basic),
 *		{}
 *	};
 *
 */
struct kunit_case {
	void (*run_case)(struct kunit *test);
	const char *name;
	const void* (*generate_params)(const void *prev, char *desc);

	/* private: internal use only. */
	enum kunit_status status;
	char *log;
};

static inline char *kunit_status_to_ok_not_ok(enum kunit_status status)
{
	switch (status) {
	case KUNIT_SKIPPED:
	case KUNIT_SUCCESS:
		return "ok";
	case KUNIT_FAILURE:
		return "not ok";
	}
	return "invalid";
}

/**
 * KUNIT_CASE - A helper for creating a &struct kunit_case
 *
 * @test_name: a reference to a test case function.
 *
 * Takes a symbol for a function representing a test case and creates a
 * &struct kunit_case object from it. See the documentation for
 * &struct kunit_case for an example on how to use it.
 */
#define KUNIT_CASE(test_name) { .run_case = test_name, .name = #test_name }

/**
 * KUNIT_CASE_PARAM - A helper for creation a parameterized &struct kunit_case
 *
 * @test_name: a reference to a test case function.
 * @gen_params: a reference to a parameter generator function.
 *
 * The generator function::
 *
 *	const void* gen_params(const void *prev, char *desc)
 *
 * is used to lazily generate a series of arbitrarily typed values that fit into
 * a void*. The argument @prev is the previously returned value, which should be
 * used to derive the next value; @prev is set to NULL on the initial generator
 * call. When no more values are available, the generator must return NULL.
 * Optionally write a string into @desc (size of KUNIT_PARAM_DESC_SIZE)
 * describing the parameter.
 */
#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
 *
 * @name:	the name of the test. Purely informational.
 * @init:	called before every test case.
 * @exit:	called after every test case.
 * @test_cases:	a null terminated array of test cases.
 *
 * A kunit_suite is a collection of related &struct kunit_case s, such that
 * @init is called before every test case and @exit is called after every
 * test case, similar to the notion of a *test fixture* or a *test class*
 * in other unit testing frameworks like JUnit or Googletest.
 *
 * Every &struct kunit_case must be associated with a kunit_suite for KUnit
 * to run it.
 */
struct kunit_suite {
	const char name[256];
	int (*init)(struct kunit *test);
	void (*exit)(struct kunit *test);
	struct kunit_case *test_cases;

	/* private: internal use only */
	char status_comment[KUNIT_STATUS_COMMENT_SIZE];
	struct dentry *debugfs;
	char *log;
};

/**
 * struct kunit - represents a running instance of a test.
 *
 * @priv: for user to store arbitrary data. Commonly used to pass data
 *	  created in the init function (see &struct kunit_suite).
 *
 * Used to store information about the current context under which the test
 * is runni