Force wrap col within colgroup

[cWenyu]

Hi, I'm using html-minifier to handle lit HTML template literal, and define each template source using html as keyword. For some reason, I have to define customer col separately and repeat to render different cols for few times. The following code snippet shows the simplest case I have, the output forces adding colgroup for col, which is not expected.

source code to be minified

import { html } from 'lit-html';
import {repeat} from 'lit/directives/repeat.js';

export default class MinifyTester {
  _renderCol() {
    return repeat(this.cols, (col) => html `<col/>`);
  }
  _renderColumnGroup() {
    return html`
      <colgroup>
        ${this._renderCol()}
      </colgroup>
    `;
  }
}

minified output:

import { html } from 'lit-html';
import {repeat} from 'lit/directives/repeat.js';

class MinifyTester {
  _renderCol() {
    return html`<colgroup><col></colgroup>`;
  }
  _renderColumnGroup() {
    return html`<colgroup>${this._renderCol()}</colgroup>`;
  }
}

export { MinifyTester as default };

col element is a special case in htmlparser.js, if there's no colgroup in the same template then have to push one and trigger start with two tags (colgroup & col).

if (tagName === 'col' && findTag('colgroup') < 0) {
  lastTag = 'colgroup';
  stack.push({ tag: lastTag, attrs: [] });
  if (handler.start) {
    await handler.start(lastTag, [], false, '');
  }
}

Is any chance to cover this case?
Thanks

[cWenyu]

A duplicated question on terser/html-minifier-terser#159