feat: glob icon theme support

[PKief]

Fixes #177650 and #12493

Summary

Adds glob pattern support (* wildcards) to file icon theme associations. Icon theme authors can now use patterns like *.test.ts, webpack.*, .env.*, or test_* in their fileNames, fileExtensions, folderNames, folderNamesExpanded, rootFolderNames, and rootFolderNamesExpanded definitions.

Worth mentioning: this doesn't introduce any breaking changes. The extension API continues supporting all existing icon themes, but just adds the glob support on top.

Approach

This follows the CSS attribute selector approach sketched by @aeschli in #177650. The implementation has three layers:

1. I've renamed getIconClasses() into getFileIconInfo(). This fn returns FileIconInfo instead of a classes string[]. The new return type carries both the existing CSS classes and optional data- attributes (data-file-name, data-file-ext, data-folder-name) that get set on the DOM element via IconLabel.

2. fileIconThemeData.ts generates CSS attribute selectors for glob keys. When a theme key contains *, the CSS generator produces attribute selectors (^=, $=, *= with case-insensitive i flag) instead of class-based selectors. Exact keys continue to use the existing class-based system unchanged.

3. Priority ordering is preserved through CSS specificity:

   • Exact fileNames > glob fileNames > exact fileExtensions > glob fileExtensions > language matches
   • Exact matches get a .name-file-icon specificity boost; glob matches intentionally omit it so exact entries always win.

Examples

An icon theme can now define:

{
  "fileNames": {
    "*.test.ts": "_test_icon",
    ".env.*": "_env_icon",
    "docker-compose.*.yml": "_docker_icon"
  },
  "fileExtensions": {
    "stories.*": "_stories_icon"
  },
  "folderNames": {
    "test_*": "_test_folder_icon"
  }
}

How to test

1. Create or modify an icon theme extension with glob patterns in fileNames, fileExtensions, or folderNames
2. Apply the theme and open a workspace with matching files/folders
3. Verify that:
   • Glob patterns match the expected files (e.g., *.test.ts matches app.test.ts, utils.test.ts)
   • Exact entries still take priority over glob patterns (e.g., tsconfig.json exact match beats tsconfig.*.json glob)
   • Folder globs work for collapsed, expanded, and root folders

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

@jrieken

Matched files:

• src/vs/editor/contrib/suggest/browser/suggestWidgetRenderer.ts

@rzhao271

Matched files:

• src/vs/workbench/contrib/preferences/browser/preferencesActions.ts

@alexr00

Matched files:

• src/vs/workbench/services/dialogs/browser/simpleFileDialog.ts

[PKief]

@microsoft-github-policy-service agree