Mocking a timer callback

[Pradeepa Senanayake]

Hello,

I have the following scenario to mock which is in a compilation unit called 'EventHandler'.

I have a function called 'RegisterTimer()'

This will register an RTOS timer using RTOS functions. We need to provide it with a callback function which will get called when the timer has expired.

That call back function will call another 'SubmitEvent()' function.

Both RegisterTimer() and SubmitEvent() will be exposed to outside through a header file. That is because SubmitEvent can be called by some other parts of the application too.

There is no implementation benefit for making the timer callback function global. Therefore, I can make it static and put it inside the same compilation unit EventHandler.

But if I want to test what is happening when the callback is called, I will have to make the callback accessible to outside or I can separate the timer callback from EventHandler compilation unit and make a new compilation unit for callbacks alone. Then I can expose the callback through a header file to other parts of the firmware.

Usually what is the best way to handle this? Whether to make the callback static or not is the main question...

[James Grenning]

Hi

Sounds like you want to test you callback function and not the callback mechanism burried in the RTOS.

To test the callback function, just call it.

If the callback is a static function, and you are unit testing, you can have a fake RegisterTimer() function that saves the callback function so you can get to it for test.

Take a look at TDD next to the RTOS articles
https://wingman-sw.com/articles/tdd-next-to-the-rtos

---

James Grenning -- Author of Test-Driven Development for Embedded C
wingman-sw.com
@jwgrenning
TDD for Embedded C
facebook.com/wingman.sw
Mobile: +1 847-630-0998

--
You received this message because you are subscribed to the Google Groups "cpputest" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cpputest+u...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.