title: Javascript: How to add data to Blob object sequentially after URL generation
body: <p>I'm creating a Blob object from a list of scripts like and then creating object URL from Blob to inject script tag into html page. </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var myScriptList = [
    'var a = 1;',
    'var b = 2;',
    'var c = a+b;'
  ];
  
  var myBlobObject = new Blob(myScriptList, {type: 'text/javascript'});
  var urlToBlob = URL.createObjectURL(myBlobObject);
  
  alert(urlToBlob);</code></pre>
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  </p>
  
  <p>The problem happens when I need to append new items to my previous blob with same URL. I did this by creating new Blob object concating previous list with new items:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var myScriptList = [
    'var a = 1;',
    'var b = 2;',
    'var c = a+b;'
  ];
  
  var myBlobObject = new Blob(myScriptList, {type: 'text/javascript'});
  var urlToBlob = URL.createObjectURL(myBlobObject);
  
  alert(urlToBlob);
  
  myScriptList.push('console.log(c)');
  
  myBlobObject = new Blob(myScriptList, {type: 'text/javascript'});
  
  // Problem is following line returns new URL
  urlToBlob = URL.createObjectURL(myBlobObject);
  
  alert(urlToBlob);</code></pre>
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  </p>
  
  <p>But I need to keep previous URL for my new Object. Is it possible? How can I do this?</p>