Merge pull request #120 from resin-io/fix/96/then-of-undefined

Fix sporadic Cannot read property 'then' of undefined

lib/browser/modules/image-writer.js

@@ -114,10 +114,8 @@ imageWriter.service('ImageWriterService', function($q, $timeout) {
    * });
    */
   this.burn = function(image, drive, onProgress) {
-
-    // Avoid writing more than once
     if (self.isBurning()) {
-      return;
+      return $q.reject(new Error('There is already a burn in progress'));
     }
 
     self.setBurning(true);

lib/components/hero-progress-button.html

@@ -5,7 +5,7 @@
 <dom-module id="hero-progress-button">
   <template>
     <style>
-      :host:not([percentage="0"]) {
+      :host[active="true"] {
         pointer-events: none;
       }
 
@@ -39,6 +39,9 @@
     Polymer({
       is: 'hero-progress-button',
       properties: {
+        active: {
+          type: Boolean
+        },
         disabled: {
           type: String
         },

lib/index.html

@@ -78,7 +78,7 @@
               <hero-badge class="block space-vertical-medium" ng-disabled="!app.selection.hasImage() || !app.selection.hasDrive()">3</hero-badge>
 
               <div class="space-vertical-large">
-                <hero-progress-button percentage="{{ app.state.progress }}" active="{{ app.writer.isBurning() }}"
+                <hero-progress-button percentage="{{ app.state.progress }}" ng-attr-active="{{ app.writer.isBurning() }}"
                   ng-click="app.burn(app.selection.getImage(), app.selection.getDrive())"
                   ng-disabled="!app.selection.hasImage() || !app.selection.hasDrive()">
                     <span ng-show="app.state.progress == 100 && app.writer.isBurning()">Finishing...</span>

tests/browser/modules/image-writer.spec.js

@@ -84,6 +84,20 @@ describe('Browser: ImageWriter', function() {
           m.chai.expect(this.performWriteStub).to.have.been.calledOnce;
         });
 
+        it('should reject the second burn attempt', function() {
+          ImageWriterService.burn('foo.img', '/dev/disk2');
+
+          let rejectError = null;
+          ImageWriterService.burn('foo.img', '/dev/disk2').catch(function(error) {
+            rejectError = error;
+          });
+
+          $rootScope.$apply();
+
+          m.chai.expect(rejectError).to.be.an.instanceof(Error);
+          m.chai.expect(rejectError.message).to.equal('There is already a burn in progress');
+        });
+
       });
 
       describe('given an unsuccesful write', function() {