How to Write Tests for MicroPython Code on the Micro:bit

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How to Write Tests for MicroPython Code on the Micro:bit

The Problem

As a programmer, you might be eager to validate the functionality of your MicroPython code. However, you may encounter challenges when trying to run tests due to the hardware dependencies of the Microbit environment. For instance, if you try to execute a doctest in a script that imports the microbit module, you might see an error indicating that there are missing modules, potentially halting your testing process.

Example of the Challenge

Using the following MicroPython script, you might encounter issues when running tests:

[[See Video to Reveal this Text or Code Snippet]]

When attempting to run the command for testing, you could see an output such as this:

[[See Video to Reveal this Text or Code Snippet]]

This error arises from the Microbit's hardware requirements, making direct testing challenging without the physical device.

Step 1: Structure Your Files Appropriately

Create a directory structure for your MicroPython project that includes a dedicated mock for the microbit module. Your project might look like this:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Implement the Mock Module

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Step 3: Write Your Testing Script

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Run Your Tests

You can run your tests with the following command:

[[See Video to Reveal this Text or Code Snippet]]

With this setup, you should see an output like this:

[[See Video to Reveal this Text or Code Snippet]]

Best Practices

When working with MicroPython on memory-constrained devices like the Microbit, it's essential to keep your testing strategies efficient. Here are some tips:

Avoid Complex Test Libraries: For embedded systems, it's best to use lighter libraries that don't take up unnecessary space.

Write Simple Tests: Focus on function-specific tests that can validate the logic without relying on the actual hardware.

Use Mocks Wisely: Mock only the parts of the microbit module that are essential for your tests to minimize complexity.

Conclusion