Tone sandhi for two 3rd tones in a row

[william-davies]

As described here:

When there are two 3rd tones in a row, the first one becomes 2nd tone. E.g. 你好 (nǐ + hǎo > ní hǎo)

However, when I test pinyin-pro:

import { pinyin } from 'pinyin-pro';
const chinese = '你好'
console.log(pinyin(chinese, {
  toneSandhi: false,
  type: 'array',
  toneType: 'num'
}));

console.log(pinyin(chinese, {
  toneSandhi: true,
  type: 'array',
  toneType: 'num'
}));

The console logs:

(2) ["ni3", "hao3"]
(2) ["ni3", "hao3"]

As far as I know, it should follow the tone sandhi rules and be ["ni2", "hao3"]. Could you please extend the tone sandhi behaviour to respect tone changes when there are two 3rd tones in a row? The current toneSandhi parameter seems to handle only tone changes for 一 and 不.

Thank you!