EditorConfig

What it is

EditorConfig is a file format and a set of editor/IDE plugins that keep basic coding style consistent across different tools and contributors. A plain-text .editorconfig file, in INI-like format, lives at the project root (and optionally in subdirectories); any editor with EditorConfig support reads it and applies the rules automatically, with no per-editor configuration required.

root = true

[*]
indent_style = space
indent_size = 2
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

[*.md]
trim_trailing_whitespace = false

Why we adopted this

• Cross-editor consistency. Contributors use different editors and IDEs; EditorConfig means indentation and line endings stay uniform without everyone hand-configuring their tool the same way.
• Prevents noisy diffs. Mismatched line endings, trailing whitespace, or missing final newlines create diff churn unrelated to the actual change — EditorConfig removes that class of noise at the source.
• Zero runtime cost. It's a static config file read by editor plugins, not a build step or CI gate — the cheapest possible way to standardize basics.
• Complements, doesn't replace, formatters. Prettier/ESLint/etc. still own language-specific style; EditorConfig covers the universal baseline (whitespace, encoding, line endings) every file type shares.

w3dev-specific notes

• Every repo has a .editorconfig at its root with root = true.
• Baseline for [*]: indent_style = space, indent_size = 2, end_of_line = lf, charset = utf-8, trim_trailing_whitespace = true, insert_final_newline = true.
• Markdown files (*.md) disable trim_trailing_whitespace — two trailing spaces is a valid hard line break in Markdown.
• Makefiles and other tab-sensitive formats get their own section with indent_style = tab.

Links

• Canonical spec: https://editorconfig.org