Removal of prefix option from cleanupIds plugin is a major feature loss

[jacott]

In commit bc07c483c3b986c66834b5fe019bb75597dd45ab the prefix option in cleanupIds was removed. In the v2 version this option used to only prefix non preserved ids.

Now the prefixIds plugin conflicts with cleanupIds in a broken manner and causes the removal of preserved ids.

Example

const {optimize} = require('svgo');

const result = optimize(`
<svg xmlns="http://www.w3.org/2000/svg" width="10" height="10">
  <g id="preserveMe">
    <rect id="other" x="0" y="0" width="1" height="1" />
  </g>
</svg>
`, {
  path: 'path-to.svg',
  multipass: true,
  js2svg: {
    indent: 2, // string with spaces or number of spaces. 4 by default
    pretty: true // boolean, false by default
  },
  plugins: [{
    name: 'preset-default',
    params: {
      overrides: {
        cleanupIds: {
          remove: true,
          minify: true,
          preserve: ['preserveMe'],
          force: true
        },
        convertShapeToPath: false,
        collapseGroups: false,
      }
    }
  }, {
    name: 'prefixIds',
    params: {
      prefix: 'myPrefix',
      prefixClassNames: false,
    }
  }],
});
console.log(result.data);

// output  is missing id:
// svg xmlns="http://www.w3.org/2000/svg" width="10" height="10">
//   <g>
//     <rect width="1" height="1"/>
//   </g>
// </svg>

Please restore the prefix option.

[TrySound]

Putting prefix into cleanupIds is semantically wrong. So let's fix prefixIds instead. What would you like prefix function to return nullable value?

{
  name: 'prefixIds',
  params: {
    prefix: (node) => {
      if (node.id === 'preserveMe') {
        return null
      }
      return 'myPrefix'
    },
    prefixClassNames: false,
  }
}

Or the same preserve option?

{
  name: 'prefixIds',
  params: {
    prefix: 'myPrefix',
    preserve: ['preserveMe'],
    prefixClassNames: false,
  }
}

[jacott]

I prefer the same preserve option plus the preservePrefixes option. That way same value can be used in cleanupIds and preserveIds

Thanks

[TrySound]

Could you clarify what preservePrefixes should do?

[jacott]

The same as in cleanupIds; any id starting with a string listed in preservePrefixes should not have the additional prefix added to it. so if an id is say "foo-123" and preservePrefixes is ["foo-", ...] then "foo-123" should not change to "myPrefix__foo-123" but stay "foo-123"