title: Electron 'open-url' event isn't triggered while app isn't running on background
body: <p>When I run my electron app on macOS, I want to read all parameters coming with deeplinkingUrl. I can able to get the deeplinkingUrl reading it from <code>process.argv</code> when my application invoked via protocol on Windows. But it is not possible on macOS because process.argv gives <code>-psn...</code> and it gives this parameter just one time when the app is launched for the first time.</p>
  
  <p>I want to trigger <code>open-url</code> via invoking the protocol from browser while my app isn't running on background on macOS. But this event is triggered only while app is running. While app is not running, app will show up but it isn't navigate according to operation which comes with deeplinkingUrl. </p>
  
  <p>I also wrote those in <code>package.json</code>:</p>
  
  <pre><code>"protocols": {
    "name": "My App",
    "schemes": [
      "myapp"
    ]
  }
  </code></pre>
  
  <p>Those from the <code>electron.js</code>:</p>
  
  <pre><code>let clickToCallObj = {};
  let deeplinkingUrl;
  let mainWindow;
  
  app.on('open-url', (event, url) =&gt; {
      event.preventDefault();
  
      const isDefaultProtocolClientSet = app.isDefaultProtocolClient('myapp');
  
      deeplinkingUrl = url;
  
      clickToCallObj.operation = utils.getOperation(deeplinkingUrl); //e.g. myapp:/call/12345 -&gt; operation: call
  
      if (mainWindow &amp;&amp; isDefaultProtocolClientSet) {
          mainWindow.isMinimized() ? mainWindow.restore() : null;
          mainWindow.focus();
  
          sendClickToCallEvent(clickToCallObj, deeplinkingUrl); //takes the action with coming operation and deeplinkingUrl
      }
  });
  </code></pre>
  
  <p>So, how can I get deeplinkingUrl when I invoke my app on macOS while it isn't running on background?</p>