SVGO crashes on a file where the <svg> element is missing both width/height and viewBox attributes

[homatyano]

The issue

If the source SVG file's element is missing both the width/height and the viewBox attributes, SVGO then zeroes the image's width and height. But these zeroes are numbers and not strings, so when cleanupAttrs() tries to use .replace() on them, it crashes.

To Reproduce

Use the cleanupAttrs() filter on the following file:

<svg xmlns="http://www.w3.org/2000/svg">
    <rect width="10" height="10"/>
</svg>

Expected behavior

SVGO gracefully handles the missing values.

Observed behavior

SVGO crashes with the following message:

TypeError: node.attributes[name].replace is not a function
    at Object.enter (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/plugins/cleanupAttrs.js:30:59)
    at visit (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/util/visit.js:12:30)
    at visit (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/util/visit.js:21:7)
    at invokePlugins (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/svgo/plugins.js:30:7)
    at Module.optimize (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/svgo.js:119:5)
    at optimize (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/svgo-node.js:90:15)
    at processSVGData (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/svgo/coa.js:400:14)
    at file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/svgo/coa.js:379:15
    at async Promise.all (index 0)
    at async Command.action (file:///opt/homebrew/Cellar/svgo/4.0.1/libexec/lib/node_modules/svgo/lib/svgo/coa.js:264:7)

Desktop

• SVGO Version: 4.0.1
• Node.js Version: v24.15.0
• OS: MacOS Tahoe 26.4.1

[KTibow]

I can't reproduce this. Can you share more details (command, config) and make sure you hit the same problem if you use SVGO from NPM?