Delete all documents in current directory

Adds a new button to the top right for deleting all documents in a
directory.

tests/unit/controllers/index-test.js

@@ -4,8 +4,89 @@ moduleFor('controller:index', 'Unit | Controller | index', {
   needs: ['controller:application', 'service:storage']
 });
 
-// Replace this with your real tests.
-test('it exists', function(assert) {
+test('#parentDir', function(assert) {
   let controller = this.subject();
-  assert.ok(controller);
+  controller.set('currentDirPath', 'islands/spain/canaries/tenerife/');
+
+  assert.equal(controller.get('parentDir'), 'islands/spain/canaries/');
+});
+
+test('#currentListingContainsDocuments', function(assert) {
+  let controller = this.subject();
+
+  controller.set('currentListing', [
+    {
+      "name": "spain/",
+      "type": "folder",
+      "isBinary": false,
+      "isFolder": true,
+      "size": null,
+      "path": "/islands/spain/",
+      "etag": "885098000"
+    }
+  ]);
+
+  assert.notOk(controller.get('currentListingContainsDocuments'),
+               'returns false when no documents are present');
+
+  controller.set('currentListing', [
+    {
+      "name": "spain/",
+      "type": "folder",
+      "isBinary": false,
+      "isFolder": true,
+      "size": null,
+      "path": "/islands/spain/",
+      "etag": "885098000"
+    },
+    {
+      "name": "lamu",
+      "type": "application/json",
+      "isBinary": false,
+      "isFolder": false,
+      "size": 202,
+      "path": "/islands/lamu",
+      "etag": "478058546"
+    }
+  ]);
+
+  assert.ok(controller.get('currentListingContainsDocuments'),
+            'returns true when no documents are present');
+});
+
+test('#documentCount', function(assert) {
+  let controller = this.subject();
+
+  controller.set('currentListing', [
+    {
+      "name": "spain/",
+      "type": "folder",
+      "isBinary": false,
+      "isFolder": true,
+      "size": null,
+      "path": "/islands/spain/",
+      "etag": "885098000"
+    },
+    {
+      "name": "lamu",
+      "type": "application/json",
+      "isBinary": false,
+      "isFolder": false,
+      "size": 202,
+      "path": "/islands/lamu",
+      "etag": "478058546"
+    },
+    {
+      "name": "dominica",
+      "type": "application/json",
+      "isBinary": false,
+      "isFolder": false,
+      "size": 202,
+      "path": "/islands/dominica",
+      "etag": "929838541"
+    }
+  ]);
+
+  assert.equal(controller.get('documentCount'), 2,
+               'returns the number of documents in the current listing');
 });