title: Thinking way to debug angular
body: <p>I get the following error:</p>
  
  <pre><code>Error: Non-assignable model expression: undefined (directive: leaflet)
      at Error (&lt;anonymous&gt;)
      at h (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:43:213)
      at Object.&lt;anonymous&gt; (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:43:326)
      at Object.e.$digest (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:87:13)
      at Object.e.$apply (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:89:198)
      at https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:16:239
      at Object.d [as invoke] (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:28:96)
      at c (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:16:160)
      at tb (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:16:356)
      at lc (https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js:16:4) angular.min.js:63
  (anonymous function) angular.min.js:63
  </code></pre>
  
  <p>Apart from the fact that I'm trying to indeed debug the above error, I would like to ask what is the best way to debug the code as the above error does not display the error line on the original code but the one at the angular.min.js file?</p>