EditorConfig and committed editor settings: the small conventions that stop whitespace diffs

What it is

EditorConfig is a file format plus a set of editor plugins. A .editorconfig file uses INI syntax with glob sections ([*], [*.py], [Makefile]) and a small set of properties: indent_style, indent_size, tab_width, end_of_line, charset, trim_trailing_whitespace and insert_final_newline. The project site describes the lookup: plugins look for .editorconfig in the directory of the opened file and in every parent directory, the search stops when the file-system root is reached or a file with root = true is found, and properties from closer files take precedence. Editor-specific workspace settings complement it. VS Code, for instance, stores workspace settings under the .vscode folder and states that when the file is added to source control, the settings for the project are shared by all users of that project; an extensions.json in the same folder lists recommended extensions.

Why it matters

Mixed tabs and spaces, CRLF endings and missing final newlines produce diffs that bury the real change and start formatter fights between contributors and agents using different editors. Plugins read the file when a file is opened and apply the settings as you type and save, before any formatter or hook runs; the project site lists editors that support the format natively without a plugin.

How to apply

• Commit a .editorconfig at the repository root with root = true, a [*] section (end_of_line = lf, charset = utf-8, insert_final_newline = true, trim_trailing_whitespace = true) and per-language indentation sections; Makefiles need indent_style = tab.
• Keep it consistent with the formatter's configuration so the editor and the formatter never disagree; the formatter stays the authority, EditorConfig is the first line.
• Commit workspace settings only where they encode project decisions (format on save, the chosen formatter, test runner paths) and keep themes, keybindings and fonts out. A recommended-extensions file is a hint, not a requirement.
• Pair end_of_line with text=auto in .gitattributes (see the related article) so that a Windows checkout does not reintroduce CRLF.
• Mention both files in the onboarding path so newcomers know they are intended.

Pitfalls

The project site notes that not every property is supported by every plugin; properties beyond the core set are the least portable. trim_trailing_whitespace damages Markdown that uses two trailing spaces for line breaks; add a [*.md] section that disables it. A committed settings file containing one person's absolute paths breaks for everyone else. EditorConfig does not reformat existing files; run the formatter once and commit that separately.