Fixed loading state not showing in IDE tree list

app/assets/javascripts/ide/stores/mutations/tree.js

@@ -17,12 +17,8 @@ export default {
     });
   },
   [types.SET_DIRECTORY_DATA](state, { data, treePath }) {
-    Object.assign(state, {
-      trees: Object.assign(state.trees, {
-        [treePath]: {
+    Object.assign(state.trees[treePath], {
       tree: data,
-        },
-      }),
     });
   },
   [types.SET_LAST_COMMIT_URL](state, { tree = state, url }) {

changelogs/unreleased/ide-tree-loading-fix.yml

+---
+title: Fixed IDE not showing loading state when tree is loading
+merge_request:
+author:
+type: fixed

spec/javascripts/ide/stores/mutations/tree_spec.js

@@ -55,6 +55,16 @@ describe('Multi-file store tree mutations', () => {
       expect(tree.tree[1].name).toBe('submodule');
       expect(tree.tree[2].name).toBe('blob');
     });
+
+    it('keeps loading state', () => {
+      mutations.CREATE_TREE(localState, { treePath: 'project/master' });
+      mutations.SET_DIRECTORY_DATA(localState, {
+        data,
+        treePath: 'project/master',
+      });
+
+      expect(localState.trees['project/master'].loading).toBe(true);
+    });
   });
 
   describe('REMOVE_ALL_CHANGES_FILES', () => {