wrap each col element in a colgroup when render col in a separate function

[cWenyu]

What happened?

Hi,
I'm using html-minifier-terser to handle HTML template literal, and define each template source using html as keyword. For some reason, I have to define customer col separately and repeated to generate col 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 the case in the future?
Thanks

Version

V7.2.0

What browsers are you seeing the problem on?

Firefox, Chrome, Safari

Link to reproduce

No response

Relevant log output

No response

Willing to submit a PR?

None

[cWenyu]

A duplicated question: kangax/html-minifier#1145