Test API¶

This file documents all of the standard testing API excluding mocking or mocking related features.

struct KUNIT_RESOURCE_T¶: represents a test managed resource

Definition

struct KUNIT_RESOURCE_T {
  void *allocation;
  void (*free)(struct KUNIT_RESOURCE_T *res);
};

Members

allocation: for the user to store arbitrary data.
free: a user supplied function to free the resource. Populated by test_alloc_resource().

Description

Represents a test managed resource, a resource which will automatically be cleaned up at the end of a test case.

struct test_kmalloc_params {
        size_t size;
        gfp_t gfp;
};

static int test_kmalloc_init(struct KUNIT_RESOURCE_T *res, void *context)
{
        struct test_kmalloc_params *params = context;
        res->allocation = kmalloc(params->size, params->gfp);

        if (!res->allocation)
                return -ENOMEM;

        return 0;
}

static void test_kmalloc_free(struct KUNIT_RESOURCE_T *res)
{
        kfree(res->allocation);
}

void *test_kmalloc(struct KUNIT_T *test, size_t size, gfp_t gfp)
{
        struct test_kmalloc_params params;
        struct KUNIT_RESOURCE_T *res;

        params.size = size;
        params.gfp = gfp;

        // TODO(felixguo@google.com): The & gets interpreted via
        // Kerneldoc but we don't want that.
        res = test_alloc_resource(test, test_kmalloc_init,
                test_kmalloc_free, & params);
        if (res)
                return res->allocation;
        else
                return NULL;
}

Example

struct KUNIT_CASE_T¶: represents an individual test case.

Definition

struct KUNIT_CASE_T {
  void (*run_case)(struct KUNIT_T *test);
  const char name[256];
};

Members

run_case: the function representing the actual test case.
name: the name of the test case.

Description

A test case is a function with the signature, void (*)(struct KUNIT_T *) that makes expectations and assertions (see EXPECT_TRUE() and ASSERT_TRUE()) about code under test. Each test case is associated with a struct KUNIT_SUITE_T and will be run after the module’s init function and followed by the module’s exit function.

A test case should be static and should only be created with the TEST_CASE() macro; additionally, every array of test cases should be terminated with an empty test case.

void add_test_basic(struct KUNIT_T *test)
{
        EXPECT_EQ(test, 1, add(1, 0));
        EXPECT_EQ(test, 2, add(1, 1));
        EXPECT_EQ(test, 0, add(-1, 1));
        EXPECT_EQ(test, INT_MAX, add(0, INT_MAX));
        EXPECT_EQ(test, -1, add(INT_MAX, INT_MIN));
}

static struct KUNIT_CASE_T example_test_cases[] = {
        TEST_CASE(add_test_basic),
        {},
};

Example

TEST_CASE¶

TEST_CASE (test_name)

A helper for creating a struct KUNIT_CASE_T

Parameters

test_name: a reference to a test case function.

Description

Takes a symbol for a function representing a test case and creates a struct test_case object from it. See the documentation for struct KUNIT_CASE_T for an example on how to use it.

struct KUNIT_SUITE_T¶: describes a related collection of struct KUNIT_CASE_T s.

Definition

struct KUNIT_SUITE_T {
  const char name[256];
  int (*init)(struct KUNIT_T *test);
  void (*exit)(struct KUNIT_T *test);
  struct KUNIT_CASE_T *test_cases;
};

Members

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.

Description

A test_module is a collection of related struct KUNIT_CASE_T 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_T must be associated with a test_module for KUnit to run it.

struct KUNIT_T¶: represents a running instance of a test.

Definition

struct KUNIT_T {
  void *priv;
};

Members

priv: for user to store arbitrary data. Commonly used to pass data created in the init function (see struct KUNIT_SUITE_T).

Description

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.

module_test¶

module_test (module)

used to register a struct KUNIT_SUITE_T with KUnit.

Parameters

module: a statically allocated struct KUNIT_SUITE_T.

Description

Registers module with the test framework. See struct KUNIT_SUITE_T for more information. Hardcoding the alignment to 8 was chosen as the most likely to remain between the compiler laying out the test module pointers in the custom section and the linker script placing the custom section in the output binary. There must be no gap between the section start and the first (test_module *) entry nor between any (test_module *) entries because the test executor views the .test_modules section as an array of (test_module *) starting at __test_modules_start.

struct KUNIT_RESOURCE_T *test_alloc_resource(struct KUNIT_T *test, int (*init)(struct KUNIT_RESOURCE_T*, void*), void (*free)(struct KUNIT_RESOURCE_T*), void *context)¶: Allocates a test managed resource.

Parameters

struct KUNIT_T *test: The test context object.
int (*init)(struct KUNIT_RESOURCE_T *, void *): a user supplied function to initialize the resource.
void (*free)(struct KUNIT_RESOURCE_T *): a user supplied function to free the resource.
void *context: for the user to pass in arbitrary data.

Description

Allocates a test managed resource, a resource which will automatically be cleaned up at the end of a test case. See struct KUNIT_RESOURCE_T for an example.

void *test_kmalloc(struct KUNIT_T *test, size_t size, gfp_t gfp)¶: Just like kmalloc() except the allocation is test managed.

Parameters

struct KUNIT_T *test: The test context object.
size_t size: The size in bytes of the desired memory.
gfp_t gfp: flags passed to underlying kmalloc().

Description

Just like kmalloc(…), except the allocation is managed by the test case and is automatically cleaned up after the test case concludes. See struct KUNIT_RESOURCE_T for more information.

void *test_kzalloc(struct KUNIT_T *test, size_t size, gfp_t gfp)¶: Just like test_kmalloc(), but zeroes the allocation.

Parameters

struct KUNIT_T *test: The test context object.
size_t size: The size in bytes of the desired memory.
gfp_t gfp: flags passed to underlying kmalloc().

Description

See kzalloc() and test_kmalloc() for more information.

test_info¶

test_info (test, fmt, ...)

Prints an INFO level message associated with the current test.

Parameters

test: The test context object.
fmt: A printk() style format string.
...: variable arguments

Description

Prints an info level message associated with the test module being run. Takes a variable number of format parameters just like printk().

test_warn¶

test_warn (test, fmt, ...)

Prints a WARN level message associated with the current test.

Parameters

test: The test context object.
fmt: A printk() style format string.
...: variable arguments

Description

See test_info().

test_err¶

test_err (test, fmt, ...)

Prints an ERROR level message associated with the current test.

Parameters

test: The test context object.
fmt: A printk() style format string.
...: variable arguments

Description

See test_info().

SUCCEED¶

SUCCEED (test)

A no-op expectation. Only exists for code clarity.

Parameters

test: The test context object.

Description

The opposite of FAIL(), it is an expectation that cannot fail. In other words, it does nothing and only exists for code clarity. See EXPECT_TRUE() for more information.

FAIL¶

FAIL (test, message)

Always causes a test to fail when evaluated.

Parameters

test: The test context object.
message: an informational message to be printed when the assertion is made.

Description

The opposite of SUCCEED(), it is an expectation that always fails. In other words, it always results in a failed expectation, and consequently always causes the test case to fail when evaluated. See EXPECT_TRUE() for more information.

EXPECT_TRUE¶

EXPECT_TRUE (test, condition)

Causes a test failure when the given expression is not true.

Parameters

test: The test context object.
condition: an arbitrary boolean expression. The test fails when this does not evaluate to true.

Description

This and expectations of the form EXPECT_* will cause the test case to fail when the specified condition is not met; however, it will not prevent the test case from continuing to run; this is otherwise known as an expectation failure.

EXPECT_FALSE¶

EXPECT_FALSE (test, condition)

Causes a test failure when the expression is not false.

Parameters

test: The test context object.
condition: an arbitrary boolean expression. The test fails when this does not evaluate to false.

Description

Sets an expectation that condition evaluates to false. See EXPECT_TRUE() for more information.

EXPECT_NOT_NULL¶

EXPECT_NOT_NULL (test, expression)

Causes a test failure when expression is NULL.

Parameters

test: The test context object.
expression: an arbitrary pointer expression. The test fails when this evaluates to NULL.

Description

Sets an expectation that expression does not evaluate to NULL. Similar to EXPECT_TRUE() but supposed to be used with pointer expressions.

EXPECT_NULL¶

EXPECT_NULL (test, expression)

Causes a test failure when expression is not NULL.

Parameters

test: The test context object.
expression: an arbitrary pointer expression. The test fails when this does not evaluate to NULL.

Description

Sets an expectation that expression evaluates to NULL. Similar to EXPECT_FALSE() but supposed to be used with pointer expressions.

EXPECT_SUCCESS¶

EXPECT_SUCCESS (test, expression)

Causes a test failure if expression does not evaluate to 0.

Parameters

test: The test context object.
expression: an arbitrary expression evaluating to an int error code. The test fails when this does not evaluate to 0.

Description

Sets an expectation that expression evaluates to 0. Implementation assumes that error codes are represented as negative values and if expression evaluates to a negative value failure message will contain a mnemonic representation of the error code (for example, for -1 it will contain EPERM).

EXPECT_ERROR¶

EXPECT_ERROR (test, expression, errno)

Causes a test failure when expression evaluates to errno.

Parameters

test: The test context object.
expression: an arbitrary expression evaluating to an int error code. The test fails when this does not evaluate to errno.
errno: expected error value, error values are expected to be negative.

Description

Sets an expectation that expression evaluates to errno, so as opposed to EXPECT_SUCCESS it verifies that expression evaluates to an error.

EXPECT_EQ¶

EXPECT_EQ (test, left, right)

Sets an expectation that left and right are equal.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an expectation that the values that left and right evaluate to are equal. This is semantically equivalent to EXPECT_TRUE(test, (left) == (right)). See EXPECT_TRUE() for more information.

EXPECT_NE¶

EXPECT_NE (test, left, right)

An expectation that left and right are not equal.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an expectation that the values that left and right evaluate to are not equal. This is semantically equivalent to EXPECT_TRUE(test, (left) != (right)). See EXPECT_TRUE() for more information.

EXPECT_LT¶

EXPECT_LT (test, left, right)

An expectation that left is less than right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an expectation that the value that left evaluates to is less than the value that right evaluates to. This is semantically equivalent to EXPECT_TRUE(test, (left) < (right)). See EXPECT_TRUE() for more information.

EXPECT_LE¶

EXPECT_LE (test, left, right)

An expectation that left is less than or equal to right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an expectation that the value that left evaluates to is less than or equal to the value that right evaluates to. Semantically this is equivalent to EXPECT_TRUE(test, (left) <= (right)). See EXPECT_TRUE() for more information.

EXPECT_GT¶

EXPECT_GT (test, left, right)

An expectation that left is greater than right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an expectation that the value that left evaluates to is greater than the value that right evaluates to. This is semantically equivalent to EXPECT_TRUE(test, (left) > (right)). See EXPECT_TRUE() for more information.

EXPECT_GE¶

EXPECT_GE (test, left, right)

An expectation that left is greater than or equal to right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an expectation that the value that left evaluates to is greater than the value that right evaluates to. This is semantically equivalent to EXPECT_TRUE(test, (left) >= (right)). See EXPECT_TRUE() for more information.

EXPECT_STREQ¶

EXPECT_STREQ (test, left, right)

An expectation that strings left and right are equal.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a null terminated string.
right: an arbitrary expression that evaluates to a null terminated string.

Description

Sets an expectation that the values that left and right evaluate to are equal. This is semantically equivalent to EXPECT_TRUE(test, !strcmp((left), (right))). See EXPECT_TRUE() for more information.

EXPECT_NOT_ERR_OR_NULL¶

EXPECT_NOT_ERR_OR_NULL (test, ptr)

An expectation that ptr is not null and not err.

Parameters

test: The test context object.
ptr: an arbitrary pointer.

Description

Sets an expectation that the value that ptr evaluates to is not null and not an errno stored in a pointer. This is semantically equivalent to EXPECT_TRUE(test, !IS_ERR_OR_NULL(ptr)). See EXPECT_TRUE() for more information.

ASSERT_TRUE¶

ASSERT_TRUE (test, condition)

Causes an assertion failure when the expression is not true.

Parameters

test: The test context object.
condition: an arbitrary boolean expression. The test fails and aborts when this does not evaluate to true.

Description

This and assertions of the form ASSERT_* will cause the test case to fail and immediately abort when the specified condition is not met. Unlike an expectation failure, it will prevent the test case from continuing to run; this is otherwise known as an assertion failure.

ASSERT_FALSE¶

ASSERT_FALSE (test, condition)

Sets an assertion that condition is false.

Parameters

test: The test context object.
condition: an arbitrary boolean expression.

Description

Sets an assertion that the value that condition evaluates to is false. This is the same as EXPECT_FALSE(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_NOT_NULL¶

ASSERT_NOT_NULL (test, expression)

Asserts that expression does not evaluate to NULL.

Parameters

test: The test context object.
expression: an arbitrary pointer expression. The test fails when this evaluates to NULL.

Description

Asserts that expression does not evaluate to NULL, see EXPECT_NOT_NULL().

ASSERT_NULL¶

ASSERT_NULL (test, expression)

Asserts that expression evaluates to NULL.

Parameters

test: The test context object.
expression: an arbitrary pointer expression. The test fails when this does not evaluate to NULL.

Description

Asserts that expression evaluates to NULL, see EXPECT_NULL().

ASSERT_SUCCESS¶

ASSERT_SUCCESS (test, expression)

Asserts that expression is 0.

Parameters

test: The test context object.
expression: an arbitrary expression evaluating to an int error code.

Description

Asserts that expression evaluates to 0. It’s the same as EXPECT_SUCCESS.

ASSERT_ERROR¶

ASSERT_ERROR (test, expression, errno)

Causes a test failure when expression does not evaluate to errno.

Parameters

test: The test context object.
expression: an arbitrary expression evaluating to an int error code. The test fails when this does not evaluate to errno.
errno: expected error value, error values are expected to be negative.

Description

Asserts that expression evaluates to errno, similar to EXPECT_ERROR.

ASSERT_EQ¶

ASSERT_EQ (test, left, right)

Sets an assertion that left and right are equal.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an assertion that the values that left and right evaluate to are equal. This is the same as EXPECT_EQ(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_NE¶

ASSERT_NE (test, left, right)

An assertion that left and right are not equal.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an assertion that the values that left and right evaluate to are not equal. This is the same as EXPECT_NE(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_LT¶

ASSERT_LT (test, left, right)

An assertion that left is less than right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an assertion that the value that left evaluates to is less than the value that right evaluates to. This is the same as EXPECT_LT(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_LE¶

ASSERT_LE (test, left, right)

An assertion that left is less than or equal to right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an assertion that the value that left evaluates to is less than or equal to the value that right evaluates to. This is the same as EXPECT_LE(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_GT¶

ASSERT_GT (test, left, right)

An assertion that left is greater than right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an assertion that the value that left evaluates to is greater than the value that right evaluates to. This is the same as EXPECT_GT(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_GE¶

ASSERT_GE (test, left, right)

An assertion that left is greater than or equal to right.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a primitive C type.
right: an arbitrary expression that evaluates to a primitive C type.

Description

Sets an assertion that the value that left evaluates to is greater than the value that right evaluates to. This is the same as EXPECT_GE(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_STREQ¶

ASSERT_STREQ (test, left, right)

An assertion that strings left and right are equal.

Parameters

test: The test context object.
left: an arbitrary expression that evaluates to a null terminated string.
right: an arbitrary expression that evaluates to a null terminated string.

Description

Sets an assertion that the values that left and right evaluate to are equal. This is the same as EXPECT_STREQ(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_NOT_ERR_OR_NULL¶

ASSERT_NOT_ERR_OR_NULL (test, ptr)

An assertion that ptr is not null and not err.

Parameters

test: The test context object.
ptr: an arbitrary pointer.

Description

Sets an assertion that the value that ptr evaluates to is not null and not an errno stored in a pointer. This is the same as EXPECT_NOT_ERR_OR_NULL(), except it causes an assertion failure (see ASSERT_TRUE()) when the assertion is not met.

ASSERT_SIGSEGV¶

ASSERT_SIGSEGV (test, expr)

An assertion that expr will cause a segfault.

Parameters

test: The test context object.
expr: an arbitrary block of code.

Description

Sets an assertion that expr, when evaluated, will cause a segfault. Currently this assertion is only really useful for testing the KUnit framework, as a segmentation fault in normal kernel code is always incorrect. However, the plan is to replace this assertion with an arbitrary death assertion similar to https://github.com/google/googletest/blob/master/googletest/docs/advanced.md#death-tests which will probably be massaged to make sense in the context of the kernel (maybe assert that a panic occurred, or that BUG() was called).

NOTE

no code after this assertion will ever be executed.

struct test_stream¶: a std::stream style string builder.

Definition

struct test_stream {
  void (*set_level)(struct test_stream *this, const char *level);
  void (*add)(struct test_stream *this, const char *fmt, ...);
  void (*append)(struct test_stream *this, struct test_stream *other);
  void (*commit)(struct test_stream *this);
  void (*clear)(struct test_stream *this);
};

Members

set_level: sets the level that this string should be printed at.
add: adds the formatted input to the internal buffer.
commit: prints out the internal buffer to the user.
clear: clears the internal buffer.

Description

A std::stream style string builder. Allows messages to be built up and printed all at once.

struct test_stream *test_new_stream(struct KUNIT_T *test)¶: constructs a new struct test_stream.

Parameters

struct KUNIT_T *test: The test context object.

Description

Constructs a new test managed struct test_stream.