Code Formatting

Prefer tabs over spaces (except for formats that require spaces, e.g. configuration files)

There is an .editorconfig file in the project that should get your IDE to display tabs as shorter 2 spaces by default.

# Unix-style newlines with a newline ending every file
[*]

charset = utf-8
end_of_line = lf
insert_final_newline = true
indent_style = tab
indent_size = 2

[*.yml]
indent_style = space
indent_size = 2

You can then change the display manually in your IDE or text-editor if you have different preferences.
This ensure developers can view code with whatever indentation they want without the flip-flopping of whitespace in the files. Reviews and diffs are also more difficult when the whitespace always changes.