Converge on a solution and update tests

Signed-off-by: Itay Dafna <[email protected]>

Author: ibdafna

js/datagrid.ts

@@ -135,19 +135,15 @@ export class DataGridModel extends DOMWidgetModel {
       // Need to update existing ViewBasedJSONModel's dataset attribute
       // before discarding.
       this.data_model.updateDataset({ data: data.data, schema: schema });
-      // Those two cause tests to fail..:
-      //
-      // this.data_model.transformStateChanged.disconnect(this.syncTransformState);
-      // this.data_model.dataSync.disconnect(this.updateDataSync);
+    } else {
+      this.data_model = new ViewBasedJSONModel({
+        data: data.data,
+        schema: schema,
+      });
+      this.data_model.transformStateChanged.connect(this.syncTransformState);
+      this.data_model.dataSync.connect(this.updateDataSync);
     }
 
-    this.data_model = new ViewBasedJSONModel({
-      data: data.data,
-      schema: schema,
-    });
-    this.data_model.transformStateChanged.connect(this.syncTransformState);
-    this.data_model.dataSync.connect(this.updateDataSync);
-
     this.updateTransforms();
     this.trigger('data-model-changed');
     this.updateSelectionModel();

tests/js/datagrid.test.ts

@@ -21,13 +21,11 @@ describe('Test trait: data', () => {
   test('Data model is updated on trait update', async () => {
     const testData = Private.createBasicTestData();
     const grid = await Private.createGridWidget({ data: testData.set1 });
-    const oldDataModel = grid.model.data_model;
     grid.model.set('_data', testData.set2);
     expect(grid.model.data_model.dataset).toEqual({
       data: testData.set2.data,
       schema: testData.set2.schema,
     });
-    expect(grid.model.data_model).not.toBe(oldDataModel);
   });
 
   test('Comm message sent to backend on frontend cell update', async () => {
@@ -125,9 +123,7 @@ describe('Test trait: data', () => {
     const oldTransforms = grid.model.data_model.transformMetadata(
       transform.columnIndex,
     );
-    const oldDataModel = grid.model.data_model;
     grid.model.set('_data', testData.set2);
-    expect(grid.model.data_model).not.toBe(oldDataModel);
     expect(
       grid.model.data_model.transformMetadata(transform.columnIndex),
     ).toEqual(oldTransforms);