Does removeAttrs support regular expression patterns for attribute matching?

Direct Answer

Yes, the removeAttrs plugin treats each entry in its attrs array as a JavaScript regular expression. Metacharacters such as (fill|stroke), .*, or ^data- are interpreted as regex patterns, not literal strings.

Confirmed Behavior

• Anchoring: Patterns are matched against the full attribute name (effectively ^pattern$). fill matches only an attribute named exactly fill; use .* explicitly for partial matches.
• Element scoping: Each entry is split on : (default elemSeparator) into an element-name pattern and an attribute-name pattern, e.g., path:fill or (path|rect):(fill|stroke). Both halves receive the same regex treatment.
• Case sensitivity: No regex flags are exposed; matching is case-sensitive. Fill and fill are distinct.
• Precedence: Removal is a union — every pattern is evaluated independently. Any match removes the attribute; there is no "last wins" or specificity priority.
• Exclusion: No dedicated keep or exclude option exists. The only built-in protection is preserveCurrentColor, which retains fill/stroke when set to currentColor. Negation must be encoded inside the regex itself (e.g., negative lookahead), which is fragile due to the plugin's anchoring.

Version Sensitivity

SVGO v1, v2, and v3 differ in plugin API and option naming. The behavior described applies to the v2/v3 removeAttrs plugin. Confirm against your installed major version.

Verification Steps

1. Inspect the installed plugin: cat node_modules/svgo/plugins/removeAttrs.js | grep -n "new RegExp" (or the equivalent path for your version).
2. Run a minimal test: create test.svg with <rect fill="red" stroke="blue" data-custom="x"/>, then run svgo --config='{plugins:[{name:"removeAttrs",params:{attrs:["(fill|stroke)"]}}]}' test.svg -o - and verify both attributes are removed.
3. Test case sensitivity: add Fill="green" to the SVG and confirm it survives the same pattern.

One Diagnostic Detail Needed

Which SVGO major version are you running (svgo --version)? The option structure and default separator changed between v1 and v2+, so the exact config syntax depends on that answer.