Fix autocomplete initial undefined state

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/26775

app/assets/javascripts/gfm_auto_complete.js.es6

@@ -367,9 +367,14 @@
       return $input.trigger('keyup');
     },
     isLoading(data) {
-      if (!data || !data.length) return false;
-      if (Array.isArray(data)) data = data[0];
-      return data === this.defaultLoadingData[0] || data.name === this.defaultLoadingData[0];
+      var dataToInspect = data;
+      if (data && data.length > 0) {
+        dataToInspect = data[0];
+      }
+
+      var loadingState = this.defaultLoadingData[0];
+      return dataToInspect &&
+        (dataToInspect === loadingState || dataToInspect.name === loadingState);
     }
   };
 }).call(this);

changelogs/unreleased/26775-fix-auto-complete-initial-loading.yml

+---
+title: Fix autocomplete initial undefined state
+merge_request:
+author:

spec/javascripts/gfm_auto_complete_spec.js.es6

@@ -62,4 +62,30 @@ describe('GfmAutoComplete', function () {
       });
     });
   });
+
+  describe('isLoading', function () {
+    it('should be true with loading data object item', function () {
+      expect(GfmAutoComplete.isLoading({ name: 'loading' })).toBe(true);
+    });
+
+    it('should be true with loading data array', function () {
+      expect(GfmAutoComplete.isLoading(['loading'])).toBe(true);
+    });
+
+    it('should be true with loading data object array', function () {
+      expect(GfmAutoComplete.isLoading([{ name: 'loading' }])).toBe(true);
+    });
+
+    it('should be false with actual array data', function () {
+      expect(GfmAutoComplete.isLoading([
+        { title: 'Foo' },
+        { title: 'Bar' },
+        { title: 'Qux' },
+      ])).toBe(false);
+    });
+
+    it('should be false with actual data item', function () {
+      expect(GfmAutoComplete.isLoading({ title: 'Foo' })).toBe(false);
+    });
+  });
 });