RepoEditor: Prevent extra network call for already opened files.

app/assets/javascripts/repo/components/repo_sidebar.vue

@@ -37,17 +37,24 @@ export default {
       let file = clickedFile;
       if (file.loading) return;
       file.loading = true;
+
       if (file.type === 'tree' && file.opened) {
         file = Store.removeChildFilesOfTree(file);
         file.loading = false;
       } else {
-        Service.url = file.url;
-        Helper.getContent(file)
-          .then(() => {
-            file.loading = false;
-            Helper.scrollTabsRight();
-          })
-          .catch(Helper.loadingError);
+        const openFile = Helper.getFileFromPath(file.url);
+        if (openFile) {
+          file.loading = false;
+          Store.setActiveFiles(openFile);
+        } else {
+          Service.url = file.url;
+          Helper.getContent(file)
+            .then(() => {
+              file.loading = false;
+              Helper.scrollTabsRight();
+            })
+            .catch(Helper.loadingError);
+        }
       }
     },
 

app/assets/javascripts/repo/helpers/repo_helper.js

@@ -263,6 +263,10 @@ const RepoHelper = {
     return Store.openedFiles.find(openedFile => Store.activeFile.url === openedFile.url);
   },
 
+  getFileFromPath(path) {
+    return Store.openedFiles.find(file => file.url === path);
+  },
+
   loadingError() {
     Flash('Unable to load this content at this time.');
   },

spec/javascripts/repo/components/repo_sidebar_spec.js

@@ -79,6 +79,20 @@ describe('RepoSidebar', () => {
         expect(Helper.getContent).toHaveBeenCalledWith(file1);
       });
 
+      it('should not fetch data for already opened files', () => {
+        const file = {
+          id: 42,
+          url: 'foo',
+        };
+
+        spyOn(Helper, 'getFileFromPath').and.returnValue(file);
+        spyOn(RepoStore, 'setActiveFiles');
+        const vm = createComponent();
+        vm.fileClicked(file);
+
+        expect(RepoStore.setActiveFiles).toHaveBeenCalledWith(file);
+      });
+
       it('should hide files in directory if already open', () => {
         spyOn(RepoStore, 'removeChildFilesOfTree').and.callThrough();
         const file1 = {