Merge pull request #86 from algolia/fix/85

Consider the key's lowercase form while grouping

src/lib/utils.js

@@ -35,6 +35,8 @@ let utils = {
   },
   /*
   * Group all objects of a collection by the value of the specified attribute
+  * If the attribute is a string, use the lowercase form.
+  *
   * eg.
   * groupBy([
   *   {name: 'Tim', category: 'dev'},
@@ -69,6 +71,9 @@ let utils = {
         throw new Error(`[groupBy]: Object has no key ${property}`);
       }
       let key = item[property];
+      if (typeof key === 'string') {
+        key = key.toLowerCase();
+      }
       if (!newCollection[key]) {
         newCollection[key] = [];
       }

test/utils-test.js

@@ -121,6 +121,24 @@ describe('utils', () => {
         ]
       });
     });
+    it('group by key considering lowercase forms', () => {
+      // Given
+      let input = [
+        {name: 'Tim', category: 'devs'},
+        {name: 'Vincent', category: 'DeVs'}
+      ];
+
+      // When
+      let actual = utils.groupBy(input, 'category');
+
+      // Expect
+      expect(actual).toEqual({
+        devs: [
+          {name: 'Tim', category: 'devs'},
+          {name: 'Vincent', category: 'DeVs'}
+        ]
+      });
+    });
     it('throw an error if key does not exist', () => {
       // Given
       let input = [