Adding action summaries function to actions model.

models/action.js

@@ -28,7 +28,7 @@ ActionSchema.statics.findById = function(id) {
 };
 
 /**
- * Finds users in an array of ids.
+ * Finds actions in an array of ids.
  * @param {String} ids array of user identifiers (uuid)
 */
 ActionSchema.statics.findByItemIdArray = function(item_ids) {
@@ -37,6 +37,36 @@ ActionSchema.statics.findByItemIdArray = function(item_ids) {
   });
 };
 
+/**
+ * Returns summaries of actions for an array of ids
+ * @param {String} ids array of user identifiers (uuid)
+*/
+ActionSchema.statics.getActionSummaries = function(item_ids) {
+  return ActionSchema.statics.findByItemIdArray(item_ids).then((rawActions) => {
+    // Create an object with a count of each action type for each item
+    const actionSummaries = rawActions.reduce((actionObj, action) => {
+      if (!actionObj[action.item_id]) {
+        actionObj[action.item_id] = {
+          type: action.action_type,
+          count: 1,
+          current_user: false //Corrent this later when we have authentication
+        };
+      } else {
+        actionObj[action.item_id].count ++;
+      }
+      return actionObj;
+    }, {});
+
+    // Return an array extracted from the actionSummaries object
+    return Object.keys(actionSummaries).reduce((actions, key) => {
+      let actionSummary = actionSummaries[key];
+      actionSummary.item_id = key;
+      actions.push(actionSummary);
+      return actions;
+    }, []);
+  });
+};
+
 const Action = mongoose.model('Action', ActionSchema);
 
 module.exports = Action;

tests/models/action.js

@@ -15,6 +15,9 @@ describe('Action: models', () => {
     }, {
       action_type: 'flag',
       item_id: '456'
+    }, {
+      action_type: 'flag',
+      item_id: '123'
     }]).then((actions) => {
       mockActions = actions;
     });
@@ -32,7 +35,28 @@ describe('Action: models', () => {
   describe('#findByItemIdArray()', () => {
     it('should find an array of actions from an array of item_ids', () => {
       return Action.findByItemIdArray(['123', '456']).then((result) => {
+        expect(result).to.have.length(3);
+      });
+    });
+  });
+
+  describe('#getActionSummaries()', () => {
+    it('should return properly formatted summaries from an array of item_ids', () => {
+      return Action.getActionSummaries(['123', '789']).then((result) => {
         expect(result).to.have.length(2);
+        const sorted = result.sort((a, b) => a.count - b.count);
+        expect(sorted[0]).to.deep.equal({
+          type: 'like',
+          count: 1,
+          item_id: '789',
+          current_user: false
+        });
+        expect(sorted[1]).to.deep.equal({
+          type: 'flag',
+          count: 2,
+          item_id: '123',
+          current_user: false
+        });
       });
     });
   });