Allow Icon Themes to Define File Extensions and Context-Sensitive Icons

[RedEagle-dh]

Current Behavior

Right now, file icons in Zed are mapped internally using the grammar field in language config .toml files. This means that:

• Icon theme extensions cannot directly define which icons should be used for specific file extensions.
• All files with the same extension share the same icon, even when a different icon would make sense in certain contexts.
• Folder icons are also limited, as they cannot be context-sensitive.

Requested Feature

Modify the icon theme system so that icon themes themselves can define the mapping between file extensions and icons, instead of relying on internal language grammars.

Benefits

• Full control for theme creators – Icon themes can explicitly define which file extensions map to which icons.
• Context-sensitive icons – Different icons can be assigned to the same file extension based on context. For example:
• package.json could have a Node.js package icon, while
• de.json inside an i18n/ folder could have a localization icon.
• Flexible folder icons – Theming extensions could set custom folder icons based on name patterns (node_modules, i18n, src, etc.).
• More compatibility with existing icon themes – This would align Zed’s behavior with how VSCode and JetBrains handle file icons.

Proposed Implementation

• Introduce an "extensions" field in file_icons within the icon theme JSON:

"file_icons": {
  "typescript": { "path": "./icons/typescript.svg", "extensions": ["ts", "tsx"] },
  "javascript": { "path": "./icons/javascript.svg", "extensions": ["js", "mjs", "cjs"] },
  "json": { "path": "./icons/json.svg", "extensions": ["json"] }
}

• Allow context-sensitive file and folder icons based on patterns:

"file_icons": {
  "package_json": { "path": "./icons/package.svg", "filenames": ["package.json"] },
  "i18n_json": { "path": "./icons/i18n.svg", "path_patterns": ["**/i18n/*.json"] }
},
"directory_icons": {
  "node_modules": { "path": "./icons/node_modules.svg", "name": "node_modules" }
}

This change would give theme creators much more flexibility and bring Zed in line with other editors’ icon customization capabilities.

Alternative Approaches

If modifying the current system is not feasible, an alternative could be to allow icon theme extensions to override the internal mapping from grammar-based icons.