Demonstrate Playwright

examples/accident-counter/src/counter.test.jsx

@@ -1,4 +1,4 @@
-import { render, screen, act } from '@testing-library/react';
+import { render, screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 
 import { Counter } from './counter';
@@ -6,96 +6,36 @@ import { Counter } from './counter';
 import '@testing-library/jest-dom/vitest';
 
 describe('Counter ', () => {
-  it('renders with an initial count of 0', () => {
+  beforeEach(() => {
     render(<Counter />);
-    const counter = screen.getByTestId('counter-count');
+  });
-    expect(counter).toHaveTextContent('0');
+
+  it('renders with an initial count of 0', () => {
+    const countElement = screen.getByTestId('counter-count');
+    expect(countElement).toHaveTextContent('0');
   });
 
   it('disables the "Decrement" and "Reset" buttons when the count is 0', () => {
-    render(<Counter />);
+    const decrementButton = screen.getByRole('button', { name: 'Decrement' });
-    const decrementButton = screen.getByRole('button', { name: /decrement/i });
+    const resetButton = screen.getByRole('button', { name: 'Reset' });
-    const resetButton = screen.getByRole('button', { name: /reset/i });
 
     expect(decrementButton).toBeDisabled();
     expect(resetButton).toBeDisabled();
   });
 
-  it('displays "days" when the count is 0', () => {
+  it.todo('displays "days" when the count is 0', () => {});
-    render(<Counter />);
-    const unit = screen.getByTestId('counter-unit');
-    expect(unit).toHaveTextContent('days');
-  });
 
-  it('increments the count when the "Increment" button is clicked', async () => {
+  it.todo('increments the count when the "Increment" button is clicked', async () => {});
-    render(<Counter />);
-    const incrementButton = screen.getByRole('button', { name: /increment/i });
-    const counter = screen.getByTestId('counter-count');
 
-    await act(async () => {
+  it.todo('displays "day" when the count is 1', async () => {});
-      await userEvent.click(incrementButton);
-    });
 
-    expect(counter).toHaveTextContent('1');
+  it.todo('decrements the count when the "Decrement" button is clicked', async () => {});
-  });
 
-  it('displays "day" when the count is 1', async () => {
+  it.todo('does not allow decrementing below 0', async () => {});
-    render(<Counter />);
-    const incrementButton = screen.getByRole('button', { name: /increment/i });
-    const unit = screen.getByTestId('counter-unit');
 
-    await act(async () => {
+  it.todo('resets the count when the "Reset" button is clicked', async () => {});
-      await userEvent.click(incrementButton);
-    });
 
-    expect(unit).toHaveTextContent('day');
+  it.todo('disables the "Decrement" and "Reset" buttons when the count is 0', () => {});
-  });
 
-  it('decrements the count when the "Decrement" button is clicked', async () => {
+  it.todo('updates the document title based on the count', async () => {});
-    render(<Counter initialCount={1} />);
-    const decrementButton = screen.getByRole('button', { name: /decrement/i });
-    const count = screen.getByTestId('counter-count');
-
-    expect(decrementButton).not.toBeDisabled();
-
-    await act(async () => {
-      await userEvent.click(decrementButton);
-    });
-
-    expect(count).toHaveTextContent('0');
-    expect(decrementButton).toBeDisabled();
-  });
-
-  it('does not allow decrementing below 0', async () => {
-    render(<Counter />);
-    const decrementButton = screen.getByRole('button', { name: /decrement/i });
-    const count = screen.getByTestId('counter-count');
-
-    await act(async () => {
-      await userEvent.click(decrementButton);
-    });
-
-    expect(count).toHaveTextContent('0');
-  });
-
-  it.todo(
-    'resets the count when the "Reset" button is clicked',
-    async () => {},
-  );
-
-  it.todo(
-    'disables the "Decrement" and "Reset" buttons when the count is 0',
-    () => {},
-  );
-
-  it('updates the document title based on the count', async () => {
-    const { getByRole } = render(<Counter />);
-    const incrementButton = getByRole('button', { name: /increment/i });
-
-    await act(async () => {
-      await userEvent.click(incrementButton);
-    });
-
-    expect(document.title).toEqual(expect.stringContaining('1 day'));
-  });
 });

examples/accident-counter/src/counter.tsx

@@ -2,8 +2,8 @@ import React from 'react';
 import { useReducer, useEffect } from 'react';
 import { reducer } from './reducer';
 
-export const Counter = ({ initialCount = 0 }) => {
+export const Counter = () => {
-  const [state, dispatch] = useReducer(reducer, { count: initialCount });
+  const [state, dispatch] = useReducer(reducer, { count: 0 });
   const unit = state.count === 1 ? 'day' : 'days';
 
   useEffect(() => {

examples/accident-counter/tests/counter.spec.js

@@ -0,0 +1,12 @@
+import { test, expect } from '@playwright/test';
+
+test.beforeEach(async ({ page }) => {
+  await page.goto('http://localhost:5173');
+});
+
+test('it has a counter', async ({ page }) => {
+  const count = page.getByTestId('counter-count');
+  const incrementButton = page.getByRole('button', { name: /increment/i });
+
+  await incrementButton.click();
+});

examples/basic-math/src/arithmetic.js

@@ -1,28 +1,7 @@
-export const add = (a, b) => {
+export const add = () => {};
-  if (typeof a === 'string') a = Number(a);
-  if (typeof b === 'string') b = Number(b);
 
-  if (isNaN(a)) throw new Error('The first argument is not a number');
+export const subtract = () => {};
-  if (isNaN(b)) throw new Error('The second argument is not a number');
 
-  return a + b;
+export const multiply = () => {};
-};
 
-export const subtract = (a = 0, b = 0) => {
+export const divide = () => {};
-  if (Array.isArray(a)) {
-    a = a.reduce((a, b) => {
-      return a - b;
-    });
-  }
-
-  return a - b;
-};
-
-export const multiply = (a, b) => {
-  return a * b;
-};
-
-export const divide = (a, b) => {
-  if (b === 0) return null;
-  return a / b;
-};

examples/basic-math/src/arithmetic.test.js

@@ -1,72 +1,9 @@
 import { describe, it, expect } from 'vitest';
-import { add, subtract, multiply, divide } from './arithmetic.js';
 
-describe('add', () => {
+describe.todo('add', () => {});
-  it('should add two positive numbers', () => {
-    expect(add(2, 2)).toBe(4);
-  });
 
-  it('should add two negative numbers', () => {
+describe.todo('subtract', () => {});
-    expect(add(-2, -2)).toBe(-4);
-  });
 
-  it('should parse strings into numbers', () => {
+describe.todo('multiply', () => {});
-    expect(add('1', '1')).toBe(2);
-  });
 
-  it('should get real angry if you give it a first argument that cannot be parsed into a number', () => {
+describe.todo('divide', () => {});
-    expect(() => add('potato', 2)).toThrow('not a number');
-  });
-
-  it('should get real angry if you give it a second argument that cannot be parsed into a number', () => {
-    expect(() => add(2, 'potato')).toThrow('not a number');
-  });
-
-  it('should throw if the first argument is not a number', () => {
-    expect(() => add(NaN, 2)).toThrow('not a number');
-  });
-
-  it('should handle floating point math as best it can', () => {
-    expect(add(1.0000001, 2.0000004)).toBeCloseTo(3.0, 1);
-  });
-});
-
-describe('subtract', () => {
-  it('should subtract one number from the other', () => {
-    expect(subtract(4, 2)).toBe(2);
-  });
-
-  it('should accept and subtract all of the numbers', () => {
-    expect(subtract([10, 5], 2)).toBe(3);
-  });
-
-  it('should default undefined values to 0', () => {
-    expect(subtract(3)).toBe(3);
-    expect(subtract(undefined, 3)).toBe(-3);
-  });
-
-  it('should default to zero if either argument is null', () => {
-    expect(subtract(3, null)).toBe(3);
-    expect(subtract(null, 3)).toBe(-3);
-  });
-});
-
-describe('multiply', () => {
-  it('should multiply two numbers', () => {
-    expect(multiply(3, 2)).toBe(6);
-  });
-});
-
-describe('divide', () => {
-  it('should divide two numbers', () => {
-    expect(divide(10, 2)).toBe(5);
-  });
-
-  it('should return null if dividing by zero', () => {
-    expect(divide(10, 0)).toBeNull();
-  });
-
-  it('should return zero if dividing by Infinity', () => {
-    expect(divide(10, Infinity)).toBe(0);
-  });
-});

examples/characters/src/characrer.test.js

@@ -0,0 +1,14 @@
+import { describe, it, expect } from 'vitest';
+import { Character } from './character.js';
+import { Person } from './person.js';
+
+describe('Character', () => {
+  it.todo(
+    'should create a character with a first name, last name, and role',
+    () => {},
+  );
+
+  it.todo('should allow you to increase the level', () => {});
+
+  it.todo('should update the last modified date when leveling up', () => {});
+});

examples/characters/src/character.js

@@ -2,21 +2,21 @@ import { Person } from './person.js';
 import { rollDice } from './roll-dice.js';
 
 export class Character extends Person {
-  constructor(firstName, lastName, role, level = 1, roll = rollDice) {
+  constructor(firstName, lastName, role) {
     super(firstName, lastName);
 
     this.role = role;
-    this.level = level;
+    this.level = 1;
 
     this.createdAt = new Date();
     this.lastModified = this.createdAt;
 
-    this.strength = roll(4, 6);
+    this.strength = rollDice(4, 6);
-    this.dexterity = roll(4, 6);
+    this.dexterity = rollDice(4, 6);
-    this.intelligence = roll(4, 6);
+    this.intelligence = rollDice(4, 6);
-    this.wisdom = roll(4, 6);
+    this.wisdom = rollDice(4, 6);
-    this.charisma = roll(4, 6);
+    this.charisma = rollDice(4, 6);
-    this.constitution = roll(4, 6);
+    this.constitution = rollDice(4, 6);
   }
 
   levelUp() {

examples/characters/src/character.test.ts

@@ -1,60 +0,0 @@
-import { describe, it, expect, vi } from 'vitest';
-import { Character } from './character.js';
-import { Person } from './person.js';
-
-const firstName = 'Ada';
-const lastName = 'Lovelace';
-const role = 'Computer Scienst';
-
-describe('Character', () => {
-  let character;
-
-  beforeEach(() => {
-    character = new Character(firstName, lastName, role, 1);
-  });
-
-  it.skip('should create a character with a first name, last name, and role', () => {
-    expect(character).toEqual({
-      firstName,
-      lastName,
-      role,
-      strength: 12,
-      wisdom: 12,
-      dexterity: 12,
-      intelligence: 12,
-      constitution: 12,
-      charisma: 12,
-      level: 1,
-      lastModified: expect.any(Date),
-      createdAt: expect.any(Date),
-      id: expect.stringContaining('person-'),
-    });
-  });
-
-  it('should allow you to increase the level', () => {
-    const initialLevel = character.level;
-
-    character.levelUp();
-
-    expect(character.level).toBeGreaterThan(initialLevel);
-  });
-
-  it('should update the last modified date when leveling up', () => {
-    const initialLastModified = character.lastModified;
-
-    character.levelUp();
-
-    expect(character.lastModified).not.toBe(initialLastModified);
-  });
-
-  it.only('should roll four six-sided die', () => {
-    const rollDiceMock = vi.fn(() => 15);
-    const character = new Character(firstName, lastName, role, 1, rollDiceMock);
-
-    expect(character.strength).toBe(15);
-    expect(rollDiceMock).toHaveBeenCalledWith(4, 6);
-    expect(rollDiceMock).toHaveBeenCalledTimes(6);
-
-    console.log(rollDiceMock.mock.calls);
-  });
-});

examples/characters/src/person.test.js

@@ -2,12 +2,11 @@ import { describe, it, expect } from 'vitest';
 import { Person } from './person.js';
 
 // Remove the `todo` from the `describe` to run the tests.
-describe('Person', () => {
+describe.todo('Person', () => {
   // This test will fail. Why?
   it('should create a person with a first name and last name', () => {
     const person = new Person('Grace', 'Hopper');
     expect(person).toEqual({
-      id: expect.stringContaining('person-'),
       firstName: 'Grace',
       lastName: 'Hopper',
     });

examples/element-factory/src/alert-button.jsx

@@ -1,10 +1,7 @@
 import { useState } from 'react';
 
-export const AlertButton = ({
+export const AlertButton = ({}) => {
-  onSubmit = () => {},
+  const [message, setMessage] = useState('Alert!');
-  defaultMessage = 'Alert!',
-}) => {
-  const [message, setMessage] = useState(defaultMessage);
 
   return (
     <div>
@@ -17,7 +14,7 @@ export const AlertButton = ({
         />
       </label>
 
-      <button onClick={() => onSubmit(message)}>Trigger Alert</button>
+      <button onClick={() => alert(message)}>Trigger Alert</button>
     </div>
   );
 };

examples/element-factory/src/alert-button.test.jsx

@@ -4,27 +4,31 @@ import userEvent from '@testing-library/user-event';
 import { AlertButton } from './alert-button';
 
 describe('AlertButton', () => {
-  beforeEach(() => {});
+  beforeEach(() => {
+    vi.spyOn(window, 'alert').mockImplementation(() => {});
+    render(<AlertButton />);
+  });
 
-  afterEach(() => {});
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
 
-  it('should render an alert button', async () => {});
+  it('should render an alert button', async () => {
-
-  it.only('should trigger an alert', async () => {
-    const handleSubmit = vi.fn();
-
-    render(<AlertButton onSubmit={handleSubmit} message="Default Message" />);
-
-    const input = screen.getByLabelText('Message');
     const button = screen.getByRole('button', { name: /trigger alert/i });
 
+    expect(button).toBeInTheDocument();
+  });
+
+  it('should trigger an alert', async () => {
+    const button = screen.getByRole('button', { name: /trigger alert/i });
+    const messageInput = screen.getByLabelText(/message/i);
+
     await act(async () => {
-      await userEvent.clear(input);
+      await userEvent.clear(messageInput);
-      await userEvent.type(input, 'Hello');
+      await userEvent.type(messageInput, 'Hello, world!');
       await userEvent.click(button);
     });
 
-    expect(handleSubmit).toHaveBeenCalled();
+    expect(window.alert).toHaveBeenCalledWith('Hello, world!');
-    expect(handleSubmit).toHaveBeenCalledWith('Hello');
   });
 });

examples/element-factory/src/button.test.js

@@ -1,26 +1,19 @@
-import { screen, fireEvent } from '@testing-library/dom';
-import userEvent from '@testing-library/user-event';
 import { createButton } from './button.js';
 
 describe('createButton', () => {
-  beforeEach(() => {
+  it('should create a button element', () => {
-    document.innerHTML = '';
+    const button = createButton();
+    expect(button.tagName).toBe('BUTTON');
   });
 
-  it.skip('should create a button element', () => {
+  it('should have the text "Click Me"', () => {
-    document.body.appendChild(createButton());
+    const button = createButton();
-
+    expect(button.textContent).toBe('Click Me');
-    const button = screen.getByRole('button', { name: 'Click Me' });
-
-    expect(button).toBeInTheDocument();
   });
 
   it('should change the text to "Clicked!" when clicked', async () => {
-    document.body.appendChild(createButton());
+    const button = createButton();
-    const button = screen.getByRole('button', { name: 'Click Me' });
+    button.click();
-
-    await userEvent.click(button);
-
     expect(button.textContent).toBe('Clicked!');
   });
 });

examples/element-factory/src/login-form.test.js

@@ -2,20 +2,45 @@ import { screen } from '@testing-library/dom';
 import userEvent from '@testing-library/user-event';
 import { createLoginForm } from './login-form';
 
-describe.todo('Login Form', async () => {
+describe('LoginForm', async () => {
-  it('should render a login form', async () => {});
+  it('should render a login form', async () => {
+    document.body.replaceChildren(createLoginForm());
+
+    const form = screen.getByRole('form', { name: /login/i });
+
+    expect(form).toBeInTheDocument();
+  });
 
   it('should render a login form with a custom action', async () => {
     // Can you make sure that the form we render has an `action` attribute set to '/custom'?
+    document.body.replaceChildren(createLoginForm({ action: '/custom' }));
+
+    const form = screen.getByRole('form', { name: /login/i });
+
+    expect(form).toHaveAttribute('action', '/custom');
   });
 
   it('should render a login form with a custom method', async () => {
     // Can you make sure that the form we render has a `method` attribute set to 'get'?
+    document.body.replaceChildren(createLoginForm({ method: 'get' }));
+
+    const form = screen.getByRole('form', { name: /login/i });
+
+    expect(form).toHaveAttribute('method', 'get');
   });
 
   it('should render a login form with a custom submit handler', async () => {
     // We'll do this one later. Don't worry about it for now.
     // If it *is* later, then you should worry about it.
     // Can you make sure that the form we render has a submit handler that calls a custom function?
+    const onSubmit = vi.fn();
+    document.body.replaceChildren(createLoginForm({ onSubmit }));
+
+    const form = screen.getByRole('form', { name: /login/i });
+    const submitButton = screen.getByRole('button', { name: /login/i });
+
+    await userEvent.click(submitButton);
+
+    expect(onSubmit).toHaveBeenCalled();
   });
 });

examples/element-factory/src/notification.jsx

@@ -0,0 +1,30 @@
+import { useState } from 'react';
+
+export const Notification = () => {
+  const [content, setContent] = useState('');
+  const [message, setMessage] = useState('');
+
+  const showNotification = () => {
+    console.log({ content });
+    if (!content) return;
+    setMessage(content);
+    setTimeout(() => setMessage(''), 3000);
+  };
+
+  return (
+    <div>
+      <label>
+        Message Content
+        <input
+          type="text"
+          value={content}
+          onChange={(event) => setContent(event.target.value)}
+        />
+      </label>
+
+      <button onClick={showNotification}>Show Notification</button>
+
+      {message && <p data-testid="message">{message}</p>}
+    </div>
+  );
+};

examples/element-factory/src/notification.test.jsx

@@ -0,0 +1,73 @@
+import { vi } from 'vitest';
+import { render, screen, act } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+
+import { Notification } from './notification';
+
+describe('Notification', () => {
+  beforeEach(() => {
+    render(<Notification />);
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it('should render a notification', async () => {
+    const input = screen.getByRole('textbox', { name: /message content/i });
+    const button = screen.getByRole('button', { name: /show notification/i });
+
+    expect(input).toBeInTheDocument();
+    expect(button).toBeInTheDocument();
+  });
+
+  it.only('should show a notification', async () => {
+    const input = screen.getByRole('textbox', { name: /message content/i });
+    const button = screen.getByRole('button', { name: /show notification/i });
+
+    await act(async () => {
+      await userEvent.type(input, 'Hello, world!');
+    });
+
+    await act(async () => {
+      await userEvent.click(button);
+    });
+
+    const message = await screen.findByTestId('message');
+
+    expect(message).toHaveTextContent('Hello, world!');
+  });
+
+  it('should not show a notification if there is no content', async () => {
+    const button = screen.getByRole('button', { name: /show notification/i });
+
+    await act(async () => {
+      await userEvent.click(button);
+    });
+
+    const message = screen.queryByTestId('message');
+
+    expect(message).not.toBeInTheDocument();
+  });
+
+  it('should hide a notification after 5 seconds', async () => {
+    const input = screen.getByRole('textbox', { name: /message content/i });
+    const button = screen.getByRole('button', { name: /show notification/i });
+
+    await act(async () => {
+      await userEvent.type(input, 'Hello, world!');
+      await userEvent.click(button);
+    });
+
+    const message = screen.getByTestId('message');
+
+    expect(message).toHaveTextContent('Hello, world!');
+
+    await act(async () => {
+      vi.advanceTimersByTime(5000);
+    });
+
+    expect(message).not.toBeInTheDocument();
+  });
+});

examples/element-factory/src/secret-input.test.js

@@ -4,14 +4,41 @@ import '@testing-library/jest-dom/vitest';
 
 import { createSecretInput } from './secret-input.js';
 
-describe.todo('createSecretInput', async () => {
+describe('createSecretInput', async () => {
-  beforeEach(() => {});
+  beforeEach(() => {
+    vi.spyOn(localStorage, 'getItem').mockReturnValue('test secret');
+    vi.spyOn(localStorage, 'setItem');
+    vi.spyOn(localStorage, 'removeItem');
 
-  afterEach(() => {});
+    document.body.innerHTML = '';
+    document.body.appendChild(createSecretInput());
+  });
 
-  it('should have loaded the secret from localStorage', async () => {});
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
 
-  it('should save the secret to localStorage', async () => {});
+  it('should have loaded the secret from localStorage', async () => {
+    expect(screen.getByLabelText('Secret')).toHaveValue('test secret');
+    expect(localStorage.getItem).toHaveBeenCalledWith('secret');
+  });
 
-  it('should clear the secret from localStorage', async () => {});
+  it('should save the secret to localStorage', async () => {
+    const input = screen.getByLabelText('Secret');
+    const button = screen.getByText('Store Secret');
+
+    await userEvent.clear(input);
+    await userEvent.type(input, 'new secret');
+    await userEvent.click(button);
+
+    expect(localStorage.setItem).toHaveBeenCalledWith('secret', 'new secret');
+  });
+
+  it('should clear the secret from localStorage', async () => {
+    const button = screen.getByText('Clear Secret');
+
+    await userEvent.click(button);
+
+    expect(localStorage.removeItem).toHaveBeenCalledWith('secret');
+  });
 });

examples/element-factory/src/tabs.test.js

@@ -3,7 +3,7 @@ import userEvent from '@testing-library/user-event';
 
 import Tabs from './tabs.svelte';
 
-describe.todo('Tabs', () => {
+describe('Tabs', () => {
   beforeEach(() => {
     render(Tabs, {
       tabs: [
@@ -14,11 +14,32 @@ describe.todo('Tabs', () => {
     });
   });
 
-  it('should render three tabs', async () => {});
+  it('should render three tabs', async () => {
+    const tabs = screen.getAllByRole('tab');
+    expect(tabs).toHaveLength(3);
+  });
 
-  it('should switch tabs', async () => {});
+  it('should switch tabs', async () => {
+    const tabs = screen.getAllByRole('tab');
+    const secondTab = tabs[1];
 
-  it('should render the content of the selected tab', async () => {});
+    await userEvent.click(secondTab);
 
-  it('should render the content of the first tab by default', async () => {});
+    expect(secondTab).toHaveAttribute('aria-selected', 'true');
+  });
+
+  it('should render the content of the selected tab', async () => {
+    const tabs = screen.getAllByRole('tab');
+    const secondTab = tabs[1];
+
+    await userEvent.click(secondTab);
+
+    const content = screen.getByRole('tabpanel', { hidden: false });
+    expect(content).toHaveTextContent('lineup');
+  });
+
+  it('should render the content of the first tab by default', async () => {
+    const content = screen.getByRole('tabpanel', { hidden: false });
+    expect(content).toHaveTextContent('We will be at this place!');
+  });
 });

examples/guess-the-number/game.test.js

@@ -9,7 +9,7 @@ describe('Game', () => {
   });
 
   it('should have a secret number', () => {
-    // This isn't really a useful test.
+    // Thisn't really a useful test.
     // Do I *really* care about the type of the secret number?
     // Do I *really* care about the name of a "private" property?
     const game = new Game();

examples/logjam/src/log.js

@@ -6,14 +6,11 @@ import { sendToServer } from './send-to-server';
  * Log a message to the console in development mode or send it to the server in production mode.
  * @param  {string} message
  */
-export function log(
+export function log(message) {
-  message,
+  if (import.meta.env.MODE !== 'production') {
-  { productionCallback = () => {}, mode = import.meta.env.MODE } = {},
-) {
-  if (mode !== 'production') {
     console.log(message);
   } else {
-    productionCallback('info', message);
+    sendToServer('info', message);
   }
 }
 

examples/logjam/src/log.test.js

@@ -1,33 +1,4 @@
 import { expect, it, vi, beforeEach, afterEach, describe } from 'vitest';
 import { log } from './log';
 
-describe('logger', () => {
+describe.todo('logger', () => {});
-  describe('development', () => {
-    it('logs to the console in development mode', () => {
-      const logSpy = vi.fn();
-
-      log('Hello World');
-
-      expect(logSpy).toHaveBeenCalledWith('Hello World');
-    });
-  });
-
-  describe('production', () => {
-    beforeEach(() => {
-      vi.stubEnv('MODE', 'production');
-    });
-
-    afterEach(() => {
-      vi.restoreAllMocks();
-    });
-
-    it('should not call console.log in production', () => {
-      const logSpy = vi.spyOn(console, 'log');
-
-      log('Hello World', { mode: 'production', productionCallback: logSpy });
-
-      expect(logSpy).not.toHaveBeenCalled();
-      expect(sendToServer).toHaveBeenCalled();
-    });
-  });
-});

examples/logjam/src/send-to-server.js

@@ -4,6 +4,5 @@
  * @param {string} message
  */
 export const sendToServer = (level, message) => {
-  throw new Error('I should not run!');
   return `You must mock this function: sendToServer(${level}, ${message})`;
 };

examples/scratchpad/__snapshots__/index.test.js.snap

@@ -0,0 +1,3 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`a super simple test 1`] = `"<div>wowowow</div>"`;

examples/scratchpad/fake-time.test.js

@@ -1,4 +1,6 @@
-import { vi, describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { vi, describe, it, expect } from 'vitest';
+
+vi.useFakeTimers();
 
 function delay(callback) {
   setTimeout(() => {
@@ -7,22 +9,13 @@ function delay(callback) {
 }
 
 describe('delay function', () => {
-  beforeEach(() => {
-    vi.useFakeTimers();
-    vi.setSystemTime('2024-02-29');
-  });
-
-  afterEach(() => {
-    vi.useRealTimers();
-  });
-
   it('should call callback after delay', () => {
     const callback = vi.fn();
 
     delay(callback);
-    vi.advanceTimersToNextTimer();
 
-    expect(callback).toHaveBeenCalled();
+    vi.advanceTimersByTime(1000);
-    expect(new Date()).toBe(null);
+
+    expect(callback).toHaveBeenCalledWith('Delayed');
   });
 });

examples/scratchpad/package.json

@@ -1,6 +1,7 @@
 {
   "name": "scratchpad",
   "version": "1.0.0",
+  "main": "index.js",
   "main": "src/index.js",
   "type": "module",
   "scripts": {

examples/task-list/src/mocks/handlers.js

@@ -11,4 +11,13 @@ const createTask = (title) => ({
   lastModified: new Date('02-29-2024').toISOString(),
 });
 
-export const handlers = [];
+export const handlers = [
+  http.get('/api/tasks', async () => {
+    return HttpResponse.json(tasks);
+  }),
+  http.post('/api/tasks', async ({ request }) => {
+    const { title } = await request.json();
+    const task = createTask(title);
+    return HttpResponse.json(task);
+  }),
+];

examples/task-list/tests/task-list.spec.js

@@ -1,8 +1,7 @@
 import { test, expect } from '@playwright/test';
 
-/** @type {import('../start-server').DevelopmentServer} */
 test.beforeEach(async ({ page }) => {
-  await page.goto('http://localhost:5173');
+  await page.goto('http://localhost:5174');
 });
 
 test('it should load the page', async ({ page }) => {
@@ -16,7 +15,7 @@ test('it should add a task', async ({ page }) => {
   await input.fill('Learn Playwright');
   await submit.click();
 
-  const heading = await page.getByRole('heading', { name: 'Learn Playwright' });
+  const heading = page.getByRole('heading', { name: 'Learn Playwright' });
 
   await expect(heading).toBeVisible();
 });

examples/utility-belt/src/string-to-number.test.js

@@ -6,5 +6,10 @@ describe('stringToNumber', () => {
     expect(stringToNumber('42')).toBe(42);
   });
 
-  it.todo('throws an error if given a string that is not a number', () => {});
+  it('throws an error if given a string that is not a number', () => {
+    const value = 'foo';
+    expect(() => stringToNumber(value)).toThrowError(
+      `cannot be parsed as a number`,
+    );
+  });
 });