epub.js coverUrl() can not return blob cover url by using this method, i have fixed

[vanilla-sky]

 the post content code line:   this.urls.indexOf(path.replace('/OEBPS/', "")); 
    only  change this line,then return right coverurl

/**

• Get a URL for a resource
• @param {string} path

• @return {string} url */

  }, { key: "get", value: function get(path) {

      var indexInUrls = this.urls.indexOf(path.replace('/OEBPS/', ""));
      if (indexInUrls === -1) {
          return;
      }
      if (this.replacementUrls.length) {
          return new Promise(function (resolve, reject) {
              resolve(this.replacementUrls[indexInUrls]);
          }.bind(this));
      } else {
          return this.createUrl(path);
      }
  }

[christiaan]

For me this did not work (or I did not understand your patch). I've created a PR https://github.com/futurepress/epub.js/pull/1056 to fix this. It also demonstrates the issue in a test to prevent regressions.