Fix tests for configuration

Author: idastambuk

e2e/configuration.spec.ts

@@ -100,15 +100,29 @@ test.describe('Configuration tests', () => {
 */
 
   test('"Save & test" should fail when configuration is invalid', async ({
+    readProvisionedDataSource,
+    gotoDataSourceConfigPage,
+  }) => {
+    const ds = await readProvisionedDataSource<DataSourcePluginOptionsEditorProps<PromOptions>>({
+      fileName: 'datasources.yml',
+    });
+    const configPage = await gotoDataSourceConfigPage(ds.uid);
+    await expect(configPage.saveAndTest()).not.toBeOK();
+    await expect(configPage).toHaveAlert('error', {
+      hasText: /.*there was an error returned querying the prometheus api/i,
+    });
+  });
+
+  test('"Save & test" should fail when url is empty', async ({
     createDataSourceConfigPage,
     readProvisionedDataSource,
   }) => {
     const ds = await readProvisionedDataSource<DataSourcePluginOptionsEditorProps<PromOptions>>({
       fileName: 'datasources.yml',
     });
     const configPage = await createDataSourceConfigPage({ type: ds.type });
-    await expect(configPage.saveAndTest()).not.toBeOK();
-    await expect(configPage).toHaveAlert('error', { hasText: 'empty url' });
+    await configPage.getByGrafanaSelector(selectors.pages.DataSource.saveAndTest).click();
+    await expect(configPage).toHaveAlert('error', {hasText: /invalid URL/i});
   });
 
   test('it should allow a user to add the version when the Prom type is selected', async ({