How to add firebase to Vuepress?

I'm trying to add firebase code into Vuepress so I can embed a simple review app into all the Vuepress pages. Wondering how to do that?

```

<script src="https://www.gstatic.com/firebasejs/5.5.6/firebase.js"></script>
<script>
  // Initialize Firebase
  var config = {
    apiKey: "asdf",
    authDomain: "adsf-9e0b6.firebaseapp.com",
    databaseURL: "https://asdf-9e0b6.firebaseio.com",
    projectId: "sadf-9e0b6",
    storageBucket: "adsf-9e0b6.appspot.com",
    messagingSenderId: "asdf"
  };
  firebase.initializeApp(config);
</script>

```

Solution

Add something like this in the config.js within the head array. Note that this adds firebase-app (core), firebase-auth, firestore, and cloud functions as I'm using 4 modules in my project.

NOTE that I'm also initializing both firebase and firestore in here. So I get firestore as a global variable.

When firebase loads, all these will be hoisted to the head section of the app.

 head: [

    [
      "script",
      {
        src: "https://www.gstatic.com/firebasejs/5.5.6/firebase-app.js"
      }
    ],

    [
      "script",
      {
        src: "https://www.gstatic.com/firebasejs/5.5.6/firebase-auth.js"
      }
    ],

    [
      "script",
      {
        src: "https://www.gstatic.com/firebasejs/5.5.6/firebase-firestore.js"
      }
    ],

    [
      "script",
      {
        src: "https://www.gstatic.com/firebasejs/5.5.6/firebase-functions.js"
      }
    ],

    [
      "script",
      {},
      `var config = {
        apiKey: "apikey",
        authDomain: "app.firebaseapp.com",
        databaseURL: "https://app.firebaseio.com",
        projectId: "appname",
        storageBucket: "appname.appspot.com",
        messagingSenderId: "12345"
      };
      firebase.initializeApp(config);
      const firestore = firebase.firestore();
      const settings = { /* your settings... */
          timestampsInSnapshots: true
      };
      firestore.settings(settings);`
    ],
    ]