Currently, the IPython test suite covers %timeit for single-line input, but it does not directly test whether %timeit produces correctly formatted output (including best time and standard deviation) for multi-line code blocks or cell magics.
This issue proposes adding a new test that:

Runs %timeit with a multi-line code block or cell magic in an IPython test.
Asserts that the output format is as expected (e.g., includes 'best' and '±' values).