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/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.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*
 * @allocation: for the user to store arbitrary data.
 * @free: a user supplied function to free the resource. Populated by
 * kunit_alloc_resource().
 *
 * Represents a *test managed resource*, a resource which will automatically be
 * cleaned up at the end of a test case.
 *
 * 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->allocation = kmalloc(params->size, params->gfp);
 *
 *		if (!res->allocation)
 *			return -ENOMEM;
 *
 *		return 0;
 *	}
 *
 *	static void kunit_kmalloc_free(struct kunit_resource *res)
 *	{
 *		kfree(res->allocation);
 *	}
 *
 *	void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
 *	{
 *		struct kunit_kmalloc_params params;
 *		struct kunit_resource *res;
 *
 *		params.size = size;
 *		params.gfp = gfp;
 *
 *		res = kunit_alloc_resource(test, kunit_kmalloc_init,
 *			kunit_kmalloc_free, &params);
 *		if (res)
 *			return res->allocation;
 *
 *		return NULL;
 *	}
 */
struct kunit_resource {
	void *allocation;
	kunit_resource_free_t free;

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

struct kunit;

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

/*
 * 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		"        "

/**
 * struct kunit_case - represents an individual test case.
 *
 * @run_case: the function representing the actual test case.
 * @name:     the name of the test case.
 *
 * 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;

	/* private: internal use only. */
	bool success;
	char *log;
};

static inline char *kunit_status_to_string(bool status)
{
	return status ? "ok" : "not ok";
}

/**
 * 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 }

/**
 * 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 */
	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 running. Most of this data is private and should only be accessed
 * indirectly via public functions; the one exception is @priv which can be
 * used by the test writer to store arbitrary data.
 */
struct kunit {
	void *priv;

	/* private: internal use only. */
	const char *name; /* Read only after initialization! */
	char *log; /* Points at case log after initialization */
	struct kunit_try_catch try_catch;
	/*
	 * success starts as true, and may only be set to false during a
	 * test case; thus, it is safe to update this across multiple
	 * threads using WRITE_ONCE; however, as a consequence, it may only
	 * be read after the test case finishes once all threads associated
	 * with the test case have terminated.
	 */
	bool success; /* Read only after test_case finishes! */
	spinlock_t lock; /* Guards all mutable test state. */
	/*
	 * Because resources is a list that may be updated multiple times (with
	 * new resources) from any thread associated with a test case, we must
	 * protect it with some type of lock.
	 */
	struct list_head resources; /* Protected by lock. */
};

void kunit_init_test(struct kunit *test, const char *name, char *log);

int kunit_run_tests(struct kunit_suite *suite);

size_t kunit_suite_num_test_cases(struct kunit_suite *suite);

unsigned int kunit_test_case_num(struct kunit_suite *suite,
				 struct kunit_case *test_case);

int __kunit_test_suites_init(struct kunit_suite **suites);

void __kunit_test_suites_exit(struct kunit_suite **suites);

/**
 * kunit_test_suites() - used to register one or more &