editorconfig

Generate a robust, comprehensive, and best-practice-oriented .editorconfig file to ensure consistent coding styles across different editors and IDEs.

Core Process

1. Analyze Context: Scan the project structure and file types to infer the languages and technologies being used.
2. Incorporate Preferences: Adhere to explicit user constraints (e.g., indentation style/size). Note any conflicts with best practices in the final explanation.
3. Apply Universal Best Practices: Enforce baseline standards (character sets, LF line endings, trailing whitespace, and final newlines).
4. Generate File: Output a structured .editorconfig file covering all relevant file types found in the project via glob patterns (*, **.js, **.py, etc.).
5. Provide Explanations: Detail the rationale for every single rule generated in a clear Markdown "Rule-by-Rule Explanation" section below the code block.

Core Principles

• Precision Targeting: Apply rules via universal and specific glob patterns without polluting unrelated scopes.
• Universal Standards: Use lf for line endings, utf-8 charset, trim trailing whitespace, and insert final newlines globally unless context demands otherwise.
• Exceptions Mapping: Explicitly disable trim_trailing_whitespace for [*.md] files since trailing whitespace holds semantic meaning (hard line breaks).

When to Use

• When requested to generate, update, or configure an .editorconfig file.
• When standardizing coding styles or formatting hooks for a workspace.

When Not to Use

• When the project already has an established .editorconfig that simply needs minor adjustments (edit the existing file rather than generating a new one from scratch).
• For enforcing complex logic constraints or code quality metrics (use Linters like ESLint or Pylint instead).
• If the repository strictly uses an automated formatter like Prettier or Black that overrides editor configurations.

Common Pitfalls

• Overriding Markdown Semantics: Setting trim_trailing_whitespace = true globally without adding an exception for [*.md], breaking Markdown's hard-line breaks (which require two trailing spaces).
• Ignoring Project Context: Generating a generic .editorconfig that defaults to 4 spaces, even when every file in the current repository clearly uses 2 spaces.
• Missing root = true: Forgetting to add root = true at the top of the file, causing editors to continue searching parent directories for conflicting rules.

Quick Start

# Top-most EditorConfig file
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

Diagnostics and Troubleshooting

• If settings are overridden by parent directories, verify that root = true is placed at the top of the file.
• If whitespace handling causes issues in Markdown or Makefiles, explicitly add overrides for [*.md] or [Makefile].

Best Practices

• Start with root = true to stop the EditorConfig search in the current directory.
• Combine the output into two parts: A single code block with the .editorconfig and a "Rule-by-Rule Explanation" section in Markdown.

What to Avoid

• Outputting an .editorconfig without rule-by-rule explanations.
• Overwriting existing .editorconfig files blindly without reading and merging current project conventions.

References

• https://github.com/github/awesome-copilot/blob/main/skills/editorconfig/SKILL.md