Running the tests doesn't check the result of the worker based pdf processing code. This should be the case.

if (!this._enhanceTextSelection || !this._renderingDone) {
      return;
    }
    if (this._bounds !== null) {
      expand(this);
      this._bounds = null;
    }
    const transformBuf = [],
      paddingBuf = [];
    for (let i = 0, ii = this._textDivs.length; i < ii; i++) {
      const div = this._textDivs[i];
      const divProps = this._textDivProperties.get(div);
      if (!divProps.hasText) {
        continue;
      }