C代码的打桩框架 - FFF （Fake Function Framework）
我只是IT圈的搬运工，项目原址https://github.com/meekrosoft/fff
FFF是一个用宏实现的小框架，只需要一个头文件fff.h，没有任何其他依赖，非常简洁。
FFF的核心就是三个宏：
FAKE_VOID_FUNC(fn [,arg_types*]);
定义一个名为fn的桩函数，返回值为空，有n个参数。
FAKE_VALUE_FUNC(return_type, fn [,arg_types*]);
定义一个名为fn的桩函数，返回值类型为return_type，有n个参数。
RESET_FAKE(fn);
重置桩函数fn的调用信息。
实现上，FFF为桩生成了一系列变量。以带有返回值并且有一个参数的桩函数为例：
#define DECLARE_FAKE_VALUE_FUNC1(RETURN_TYPE, FUNCNAME, ARG0_TYPE) \
EXTERN_C \
typedef struct FUNCNAME##_Fake { \
DECLARE_ARG(ARG0_TYPE, 0, FUNCNAME) \
DECLARE_ALL_FUNC_COMMON \
DECLARE_VALUE_FUNCTION_VARIABLES(RETURN_TYPE) \
RETURN_TYPE(*custom_fake)(ARG0_TYPE arg0); \
} FUNCNAME##_Fake;\
extern FUNCNAME##_Fake FUNCNAME##_fake;\
void FUNCNAME##_reset(); \
END_EXTERN_C \
DECLARE_ARG生成了存储当前参数值的变量和存储历史参数值的数组。
#define DECLARE_ARG(type, n, FUNCNAME) \ type arg##n##_val; \ type arg##n##_history[FFF_ARG_HISTORY_LEN];
DECLARE_ALL_FUNC_COMMON定义了桩被调用的次数，参数历史数组的长度以及调用HISTORY_DROPPED的次数。
#define DECLARE_ALL_FUNC_COMMON \ unsigned int call_count; \ unsigned int arg_history_len;\ unsigned int arg_histories_dropped; \
DECLARE_VALUE_FUNCTION_VARIABLES定义了桩函数返回值相关的数据。
custom_fake提供了一个回调接口，可以用自己的函数来构造返回值。
实例：
#include "UI.h"
#include "../../fff.h"
#include "SYSTEM.h"
#include "DISPLAY.h"
#include <assert.h>
#include <stdio.h>
#include <string.h>
/* Test Framework :-) */
void setup();
#define TEST_F(SUITE, NAME) void NAME()
#define RUN_TEST(SUITE, TESTNAME) printf(" Running %s.%s: \n", #SUITE, #TESTNAME); setup(); TESTNAME(); printf(" SUCCESS\n");
DEFINE_FFF_GLOBALS;
/* SYSTEM.h */
FAKE_VOID_FUNC2(SYSTEM_register_irq, irq_func_t, unsigned int);
/* DISPLAY.h */
FAKE_VOID_FUNC(DISPLAY_init);
FAKE_VOID_FUNC(DISPLAY_clear);
FAKE_VOID_FUNC(DISPLAY_output, char *);
FAKE_VALUE_FUNC(unsigned int, DISPLAY_get_line_capacity);
FAKE_VALUE_FUNC(unsigned int, DISPLAY_get_line_insert_index);
FAKE_VOID_FUNC0(button_press_cbk);
/* Initialializers called for every test */
void setup()
{
RESET_FAKE(SYSTEM_register_irq);
RESET_FAKE(DISPLAY_init)
RESET_FAKE(DISPLAY_clear)
RESET_FAKE(DISPLAY_output)
RESET_FAKE(DISPLAY_get_line_capacity)
RESET_FAKE(DISPLAY_get_line_insert_index);
RESET_FAKE(button_press_cbk);
FFF_RESET_HISTORY();
DISPLAY_get_line_capacity_fake.return_val = 2;
}
/* Tests go here */
TEST_F(UITests, init_will_initialise_display)
{
UI_init();
assert(DISPLAY_init_fake.call_count == 1);
}
TEST_F(UITests, init_will_register_interrupt_gpio2)
{
UI_init();
assert(SYSTEM_register_irq_fake.call_count == 1);
assert(SYSTEM_register_irq_fake.arg0_val == UI_button_irq_handler);
assert(SYSTEM_register_irq_fake.arg1_val == IRQ_GPIO_2);
}
TEST_F(UITests, when_no_irq_then_missed_irq_counter_zero)
{
assert(UI_get_missed_irqs() == 0);
}
TEST_F(UITests, when_one_irq_and_no_handler_then_missed_irq_counter_one)
{
UI_button_irq_handler();
assert(UI_get_missed_irqs() == 1);
}
TEST_F(UITests, when_one_irq_and_valid_callback_then_missed_irq_counter_zero)
{
UI_init();
UI_register_button_cbk(button_press_cbk);
UI_button_irq_handler();
assert(UI_get_missed_irqs() == 0);
}
TEST_F(UITests, when_one_irq_and_valid_callback_then_callback_called)
{
UI_register_button_cbk(button_press_cbk);
UI_button_irq_handler();
assert(button_press_cbk_fake.call_count == 1);
}
TEST_F(UITests, write_line_outputs_lines_to_display)
{
char msg[] = "helloworld";
UI_write_line(msg);
assert(DISPLAY_output_fake.call_count == 1);
assert(strncmp(DISPLAY_output_fake.arg0_val, msg, 26) == 0);
}
TEST_F(UITests, when_no_empty_lines_write_line_clears_screen_and_outputs_lines_to_display)
{
DISPLAY_get_line_insert_index_fake.return_val = 2;
char msg[] = "helloworld";
UI_write_line(msg);
assert(DISPLAY_clear_fake.call_count == 1);
assert(DISPLAY_output_fake.call_count == 1);
// Check the order of the calls: Don't care about the first two:
// DISPLAY_get_line_capacity and DISPLAY_get_line_insert_index
assert(fff.call_history_idx == 4);
assert(fff.call_history[2] == (void *) DISPLAY_clear);
assert(fff.call_history[3] == (void *) DISPLAY_output);
}
TEST_F(UITests, when_empty_lines_write_line_doesnt_clear_screen)
{
// given
DISPLAY_get_line_insert_index_fake.return_val = 1;
char msg[] = "helloworld";
// when
UI_write_line(msg);
// then
assert(DISPLAY_clear_fake.call_count == 0);
}
TEST_F(UITests, when_string_longer_than_26_then_truncated_string_output)
{
// given
char input[] = "abcdefghijklmnopqrstuvwxyz0123456789";
char expected[] = "abcdefghijklmnopqrstuvwxyz";
// when
UI_write_line(input);
// then
assert(strncmp(expected, DISPLAY_output_fake.arg0_val, 37) == 0);
}
TEST_F(UITests, when_outputting_to_full_display_then_previous_inserted)
{
// given
DISPLAY_get_line_insert_index_fake.return_val = 1;
char oldest[] = "oldest";
char newest[] = "newest";
// when
UI_write_line(oldest);
UI_write_line(newest);
// then
assert(DISPLAY_output_fake.call_count == 2);
// fills last line
assert(strncmp(oldest, DISPLAY_output_fake.arg0_history[0], 37) == 0);
//clears
assert(DISPLAY_clear_fake.call_count == 1);
// inserts old line at first
assert(strncmp(oldest, DISPLAY_output_fake.arg0_history[1], 37) == 0);
// then inserts new line
assert(strncmp(newest, DISPLAY_output_fake.arg0_history[2], 37) == 0);
}
int main()
{
setbuf(stdout, NULL);
fprintf(stdout, "-------------\n");
fprintf(stdout, "Running Tests\n");
fprintf(stdout, "-------------\n\n");
fflush(0);
/* Run tests */
RUN_TEST(UITests, init_will_initialise_display);
RUN_TEST(UITests, init_will_register_interrupt_gpio2);
RUN_TEST(UITests, when_no_irq_then_missed_irq_counter_zero);
RUN_TEST(UITests, when_one_irq_and_no_handler_then_missed_irq_counter_one);
RUN_TEST(UITests, when_one_irq_and_valid_callback_then_missed_irq_counter_zero);
RUN_TEST(UITests, when_one_irq_and_valid_callback_then_callback_called);
RUN_TEST(UITests, write_line_outputs_lines_to_display);
RUN_TEST(UITests, when_no_empty_lines_write_line_clears_screen_and_outputs_lines_to_display);
RUN_TEST(UITests, when_empty_lines_write_line_doesnt_clear_screen);
RUN_TEST(UITests, when_string_longer_than_26_then_truncated_string_output);
printf("\n-------------\n");
printf("Complete\n");
printf("-------------\n\n");
return 0;
}