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- # bdd-for-c-mocks
-
- ## Usage
-
- Suppose you have a library `lib` and an application `app` that uses `lib`. You want to test `app` and you want to mock
- `lib`'s functions. You can do this by creating a mock header file for `lib` and including it in `app`'s test file.
-
- ### `lib.h`
-
- This is a reference header file for `lib`. The implementation should be abstracted from us, and we want to be able to
- mock its behavior.
-
- ```c
- #ifndef LIB_H
- #define LIB_H
-
- int add(int a, int b);
-
- void alert();
-
- #endif
- ```
-
- ### `lib.mock.h`
-
- We define mocked behavior for `lib`. `bdd-for-c-mocks` offers a capability to force mock behavior through modes. Note
- that all mode behaviors should be implemented already.
-
- ```c
- #ifndef LIB_MOCK_H
- #define LIB_MOCK_H
-
- #include <bdd-for-c-mocks.h>
-
- mock_modes(add) {
- ADD_RETURNS_SUM = 0,
- ADD_RETURNS_CONSTANT_VALUE,
- };
-
- mock(add) int add(int a, int b) {
- mock_mode_if(add, ADD_RETURNS_SUM) {
- // suppose we want to test normal behavior
- mock_return(add) a + b;
- } else mock_mode_if(add, ADD_RETURNS_CONSTANT_VALUE) {
- // maybe an edge case?
- mock_return(add) 5;
- }
- }
-
- mock(alert) void alert() {
- mock_return(alert);
- }
-
- #endif
- ```
-
- ### `app.h`
- ```c
- #ifndef APP_H
- #define APP_H
-
- void math();
-
- #endif
- ```
-
- ### `app.c`
-
- This is a reference implementation of `app`. We want to test the invocations done inside the `math()` function.
-
- ```c
- #include "lib.h"
- #include "app.h"
-
- void math() {
- int result_a = add(1, 2);
- int result_b = add(3, 4);
- if (result_a == result_b) {
- // this is the edge case!
- // alert() should be called if the add values are the same
- alert();
- }
- }
- ```
-
- ### `app.test.c`
-
- This is the test file for `app`. It includes `lib.mock.h` instead of `lib.c`. `lib.h` should still be linked because we
- are sharing the original function declarations.
-
- ```c
- #include <bdd-for-c.h>
- #include "app.h"
-
- spec("app") {
- describe("math") {
- after_each() {
- mock_reset(add);
- }
-
- after_each() {
- mock_reset(alert);
- }
-
- it("calls add") {
- mock_mode(add, ADD_RETURNS_SUM);
- mock_set_excepted_calls(math, 2);
-
- math();
-
- check(
- mock_get_expected_calls(math) == mock_get_actual_calls(math),
- "add was not called."
- );
- }
-
- it("calls alert when calls from add return the same values") {
- mock_mode(add, ADD_RETURNS_CONSTANT_VALUE);
-
- math();
- check(mock_is_called(alert), "alert was not called.");
- }
- }
- }
-
- ```
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