Merge branch '270095-editor-lite-cursor' into 'master'

Fixing the recursive update of the Editor Lite

See merge request gitlab-org/gitlab!45546

app/assets/javascripts/vue_shared/components/editor_lite.vue

@@ -58,7 +58,9 @@ export default {
       this.editor.updateModelLanguage(newVal);
     },
     value(newVal) {
-      this.editor.setValue(newVal);
+      if (this.editor.getValue() !== newVal) {
+        this.editor.setValue(newVal);
+      }
     },
   },
   mounted() {

spec/frontend/vue_shared/components/editor_lite_spec.js

@@ -96,17 +96,6 @@ describe('Editor Lite component', () => {
       });
     });
 
-    it('reacts to the changes in the pased value', async () => {
-      const newValue = 'New Value';
-
-      wrapper.setProps({
-        value: newValue,
-      });
-
-      await nextTick();
-      expect(setValue).toHaveBeenCalledWith(newValue);
-    });
-
     it('registers callback with editor onChangeContent', () => {
       expect(onDidChangeModelContent).toHaveBeenCalledWith(expect.any(Function));
     });
@@ -127,5 +116,29 @@ describe('Editor Lite component', () => {
 
       expect(wrapper.emitted()['editor-ready']).toBeDefined();
     });
+
+    describe('reaction to the value update', () => {
+      it('reacts to the changes in the passed value', async () => {
+        const newValue = 'New Value';
+
+        wrapper.setProps({
+          value: newValue,
+        });
+
+        await nextTick();
+        expect(setValue).toHaveBeenCalledWith(newValue);
+      });
+
+      it("does not update value if the passed one is exactly the same as the editor's content", async () => {
+        const newValue = `${value}`; // to make sure we're creating a new String with the same content and not just a reference
+
+        wrapper.setProps({
+          value: newValue,
+        });
+
+        await nextTick();
+        expect(setValue).not.toHaveBeenCalled();
+      });
+    });
   });
 });