chromium/third_party/blink/web_tests/fast/text/line-break/phrase-ja.html

<!DOCTYPE html>
<style>
.container {
  font-size: 10px;
}
.wrapper {
  display: inline-block;
  vertical-align: top;
}
.phrase {
  word-break: auto-phrase;
  border-right: 1px solid blue;
}
.overflow {
  overflow-wrap: anywhere;
}
</style>
<div class="container" lang="ja">
  <div class="phrase">今日はよい天気です。</div>
  <div class="phrase overflow">今日はよい天気です。</div>
  <div class="phrase">あなたに寄り添う最先端のテクノロジー。</div>
  <div class="phrase">優れた性能をうれしい価格で。</div>
</div>
<script>
const min = 10;
const step = 10;
const elements = Array.from(document.getElementsByClassName('phrase'));
for (const element of elements) {
  const wrapper = document.createElement('div');
  wrapper.className = 'wrapper';
  const parent = element.parentNode;
  parent.replaceChild(wrapper, element);
  element.style.width = 'fit-content';
  wrapper.appendChild(element);
  let width = element.offsetWidth;
  for (width -= step; width >= min; width -= step) {
    const clone = element.cloneNode(true);
    clone.style.width = `${width}px`;
    wrapper.appendChild(clone);
  }
}
</script>