e2e: notebook infra/cleanup (#9831)

### Summary

The objective of this PR was to update some of the e2e Positron Notebook
infra to make the tests more maintainable and reliable (fixed some
flakes). I also removed a quite a few hardcoded waits that weren't
necessary once the assertions were improved. I will be keeping an eye on
them to quickly address any upcoming flakes.

### QA Notes

@:positron-notebooks

Author: midleman

test/e2e/fixtures/test-setup/settings.fixtures.ts

@@ -29,6 +29,8 @@ export function SettingsFixture(app: Application) {
 			}
 
 			if (waitForReady) {
+				await app.code.driver.page.waitForTimeout(3000);
+				await app.code.driver.page.locator('.monaco-workbench').waitFor({ state: 'visible' });
 				await app.workbench.sessions.expectNoStartUpMessaging();
 			}
 		},

test/e2e/infra/workbench.ts

@@ -115,12 +115,12 @@ export class Workbench {
 		this.output = new Output(code, this.quickaccess, this.quickInput);
 		this.console = new Console(code, this.quickInput, this.quickaccess, this.hotKeys, this.contextMenu);
 		this.modals = new Modals(code, this.toasts, this.console);
+		this.clipboard = new Clipboard(code, this.hotKeys);
 		this.sessions = new Sessions(code, this.quickaccess, this.quickInput, this.console);
 		this.notebooks = new Notebooks(code, this.quickInput, this.quickaccess, this.hotKeys);
 		this.notebooksVscode = new VsCodeNotebooks(code, this.quickInput, this.quickaccess, this.hotKeys);
-		this.notebooksPositron = new PositronNotebooks(code, this.quickInput, this.quickaccess, this.hotKeys);
+		this.notebooksPositron = new PositronNotebooks(code, this.quickInput, this.quickaccess, this.hotKeys, this.clipboard);
 		this.welcome = new Welcome(code);
-		this.clipboard = new Clipboard(code, this.hotKeys);
 		this.terminal = new Terminal(code, this.quickaccess, this.clipboard);
 		this.viewer = new Viewer(code);
 		this.editor = new Editor(code);

test/e2e/pages/clipboard.ts

@@ -16,19 +16,38 @@ export class Clipboard {
 		// Seed the clipboard
 		await this.setClipboardText(seed);
 
-		// Invoke the copy hotkey
-		await this.hotKeys.copy();
-
 		// Wait until clipboard value differs from the seed
 		await expect
-			.poll(async () => (await this.getClipboardText()) ?? '', {
+			.poll(async () => {
+				await this.hotKeys.copy();
+				return (await this.getClipboardText()) ?? '';
+			}, {
 				message: 'clipboard should change after copy',
 				timeout: timeoutMs,
 				intervals: [100, 150, 200, 300, 500, 800],
 			})
 			.not.toBe(seed);
 	}
 
+	async cut(timeoutMs = 5000): Promise<void> {
+		const seed = '__SEED__';
+		// Seed the clipboard
+		await this.setClipboardText(seed);
+
+		// Wait until clipboard value differs from the seed
+		await this.hotKeys.cut();
+
+		await expect
+			.poll(async () => {
+				return (await this.getClipboardText()) ?? '';
+			}, {
+				message: 'clipboard should change after cut',
+				timeout: timeoutMs,
+				intervals: [100, 150, 200, 300, 500, 800],
+			})
+			.not.toBe(seed);
+	}
+
 	async paste(): Promise<void> {
 		await this.hotKeys.paste();
 	}

test/e2e/pages/hotKeys.ts

@@ -201,8 +201,15 @@ export class HotKeys {
 		await this.pressHotKeys('Cmd+J K', 'Open workspace settings JSON', true);
 	}
 
-	public async reloadWindow() {
+	public async reloadWindow(waitForReady = false) {
 		await this.pressHotKeys('Cmd+R R', 'Reload window');
+
+		// wait for workbench to disappear, reappear and be ready
+		await this.code.driver.page.waitForTimeout(3000);
+		await this.code.driver.page.locator('.monaco-workbench').waitFor({ state: 'visible' });
+		if (waitForReady) {
+			await expect(this.code.driver.page.locator('text=/^Starting up|^Starting|^Preparing|^Discovering( \\w+)? interpreters|starting\\.$/i')).toHaveCount(0, { timeout: 90000 });
+		}
 	}
 
 	public async openWelcomeWalkthrough() {

test/e2e/pages/notebooks.ts

@@ -119,7 +119,7 @@ export class Notebooks {
 		});
 	}
 
-	async addCodeToCellAtIndex(code: string, cellIndex = 0, delay = 0) {
+	async addCodeToCellAtIndex(cellIndex: number, code: string, delay = 0) {
 		await test.step('Add code to first cell', async () => {
 			await this.selectCellAtIndex(cellIndex);
 			await this.typeInEditor(code, delay);