Add line numbers test

Fixes #141054

Author: rzhao271

test/automation/src/settings.ts

@@ -56,7 +56,7 @@ export class SettingsEditor {
 
 	async openUserSettingsUI(): Promise<void> {
 		await this.quickaccess.runCommand('workbench.action.openSettings2');
-		await this.code.waitForElement('.settings-group-title-label');
+		await this.code.waitForElement('.settings-editor');
 	}
 
 	async searchSettingsUI(query: string): Promise<void> {

test/smoke/src/areas/preferences/preferences.test.ts

@@ -16,10 +16,10 @@ export function setup(logger: Logger) {
 			const app = this.app as Application;
 
 			await app.workbench.settingsEditor.openUserSettingsFile();
-			await app.code.waitForElements('.line-numbers', false, elements => !!elements.length);
+			await app.code.waitForElements('.margin .line-numbers', false, elements => !!elements.length);
 
 			await app.workbench.settingsEditor.addUserSetting('editor.lineNumbers', '"off"');
-			await app.code.waitForElements('.line-numbers', false, result => !result || result.length === 0);
+			await app.code.waitForElements('.margin .line-numbers', false, elements => !elements || elements.length === 0);
 		});
 
 		it('changes "workbench.action.toggleSidebarPosition" command key binding and verifies it', async function () {
@@ -43,9 +43,24 @@ export function setup(logger: Logger) {
 			const app = this.app as Application;
 
 			await app.workbench.settingsEditor.searchSettingsUI('@id:editor.tabSize');
-			await app.code.waitForSetValue('.settings-editor .setting-item-contents .setting-item-control input', '15');
+			await app.code.waitForSetValue('.settings-editor .setting-item-contents .setting-item-control input', '6');
 			await app.code.waitForElement('.settings-editor .setting-item-contents .setting-item-modified-indicator');
-			await app.code.waitForSetValue('.settings-editor .setting-item-contents .setting-item-control input', '14');
+			await app.code.waitForSetValue('.settings-editor .setting-item-contents .setting-item-control input', '4');
+		});
+
+		it('turns off editor line numbers and verifies the live change', async function () {
+			const app = this.app as Application;
+
+			await app.workbench.editors.newUntitledFile();
+			await app.code.dispatchKeybinding('enter');
+			await app.code.waitForElements('.margin .line-numbers', false, elements => !!elements.length);
+
+			await app.workbench.settingsEditor.searchSettingsUI('editor.lineNumbers');
+			await app.code.waitAndClick('.settings-editor .monaco-list-rows .setting-item-control select', 2, 2);
+			await app.code.waitAndClick('.context-view .option-text', 2, 2);
+
+			await app.workbench.editors.selectTab('Untitled-1');
+			await app.code.waitForElements('.margin .line-numbers', false, elements => !elements || elements.length === 0);
 		});
 	});
 }