Fixed none merge request files not being openable in the web IDE

app/assets/javascripts/ide/components/repo_editor.vue

@@ -140,7 +140,7 @@ export default {
         this.file.staged && this.file.key.indexOf('unstaged-') === 0 ? head : null,
       );
 
-      if (this.viewer === viewerTypes.mr) {
+      if (this.viewer === viewerTypes.mr && this.file.mrChange) {
         this.editor.attachMergeRequestModel(this.model);
       } else {
         this.editor.attachModel(this.model);

app/assets/javascripts/ide/stores/utils.js

@@ -44,6 +44,7 @@ export const dataStructure = () => ({
   size: 0,
   parentPath: null,
   lastOpenedAt: 0,
+  mrChange: null,
 });
 
 export const decorateData = entity => {

spec/javascripts/ide/components/repo_editor_spec.js

@@ -24,7 +24,7 @@ describe('RepoEditor', () => {
     f.active = true;
     f.tempFile = true;
     vm.$store.state.openFiles.push(f);
-    vm.$store.state.entries[f.path] = f;
+    Vue.set(vm.$store.state.entries, f.path, f);
     vm.monaco = true;
 
     vm.$mount();
@@ -215,6 +215,30 @@ describe('RepoEditor', () => {
       expect(vm.editor.attachModel).toHaveBeenCalledWith(vm.model);
     });
 
+    it('attaches model to merge request editor', () => {
+      vm.$store.state.viewer = 'mrdiff';
+      vm.file.mrChange = true;
+      spyOn(vm.editor, 'attachMergeRequestModel');
+
+      Editor.editorInstance.modelManager.dispose();
+
+      vm.setupEditor();
+
+      expect(vm.editor.attachMergeRequestModel).toHaveBeenCalledWith(vm.model);
+    });
+
+    it('does not attach model to merge request editor when not a MR change', () => {
+      vm.$store.state.viewer = 'mrdiff';
+      vm.file.mrChange = false;
+      spyOn(vm.editor, 'attachMergeRequestModel');
+
+      Editor.editorInstance.modelManager.dispose();
+
+      vm.setupEditor();
+
+      expect(vm.editor.attachMergeRequestModel).not.toHaveBeenCalledWith(vm.model);
+    });
+
     it('adds callback methods', () => {
       spyOn(vm.editor, 'onPositionChange').and.callThrough();