Intermediate Chapter 6 · 8 min read

Assertions

Verify your app with auto-retrying assertions — toBeVisible, toHaveText, toHaveValue, negation, and plain value assertions.

Locator Assertions

Locator assertions take a locator, auto-wait, and retry until the condition is met or the timeout expires (5 seconds by default). They must always be awaited. These cover the state of any element:

state.test.ts

import { test, expect } from '@mobilewright/test';

test('element state assertions', async ({ screen }) => {
  await expect(screen.getByText('Welcome')).toBeVisible();
  await expect(screen.getByText('Loading')).toBeHidden();
  await expect(screen.getByRole('button', { name: 'Submit' })).toBeEnabled();
  await expect(screen.getByRole('checkbox')).toBeChecked();
  await expect(screen.getByRole('tab', { name: 'Home' })).toBeSelected();

  // Text and value checks — strings or regular expressions
  await expect(screen.getByTestId('greeting')).toHaveText('Hello, World');
  await expect(screen.getByTestId('greeting')).toContainText('Hello');
  await expect(screen.getByLabel('Email')).toHaveValue(/example\.com/);
});

state.test.js

const { test, expect } = require('@mobilewright/test');

test('element state assertions', async ({ screen }) => {
  await expect(screen.getByText('Welcome')).toBeVisible();
  await expect(screen.getByText('Loading')).toBeHidden();
  await expect(screen.getByRole('button', { name: 'Submit' })).toBeEnabled();
  await expect(screen.getByRole('checkbox')).toBeChecked();
  await expect(screen.getByRole('tab', { name: 'Home' })).toBeSelected();

  // Text and value checks — strings or regular expressions
  await expect(screen.getByTestId('greeting')).toHaveText('Hello, World');
  await expect(screen.getByTestId('greeting')).toContainText('Hello');
  await expect(screen.getByLabel('Email')).toHaveValue(/example\.com/);
});

Assertion	Passes when
`toBeVisible()`	Element exists and is visible
`toBeHidden()`	Element does not exist or is not visible
`toBeEnabled()` / `toBeDisabled()`	Element is enabled / disabled
`toBeChecked()`	Checkbox or switch is checked
`toBeFocused()`	Element has focus
`toBeSelected()`	Element (e.g. a tab) is selected
`toHaveText(expected)`	Text matches exactly (string) or by pattern (RegExp)
`toContainText(expected)`	Text contains the substring
`toHaveValue(expected)`	Input value matches string or RegExp

Negation and Timeouts

Add .not before any assertion to flip it, and pass a timeout option when one check needs more (or less) time than the default:

negation.test.ts

import { test, expect } from '@mobilewright/test';

test('negation and custom timeouts', async ({ screen }) => {
  // .not flips any assertion
  await expect(screen.getByText('Error')).not.toBeVisible();
  await expect(screen.getByRole('button')).not.toBeDisabled();

  // Give a slow screen more time (10 seconds instead of 5)
  await expect(screen.getByText('Done')).toBeVisible({ timeout: 10_000 });
});

negation.test.js

const { test, expect } = require('@mobilewright/test');

test('negation and custom timeouts', async ({ screen }) => {
  // .not flips any assertion
  await expect(screen.getByText('Error')).not.toBeVisible();
  await expect(screen.getByRole('button')).not.toBeDisabled();

  // Give a slow screen more time (10 seconds instead of 5)
  await expect(screen.getByText('Done')).toBeVisible({ timeout: 10_000 });
});

Value Assertions

When expect receives a plain value instead of a locator, you get the standard matchers you know from Jest. Important: these check the value once — they do not auto-wait or retry:

values.test.ts

import { test, expect } from '@mobilewright/test';

test('plain value assertions', async ({ screen }) => {
  const count = await screen.getByRole('listitem').count();

  expect(count).toBe(5);                 // strict equality
  expect(count).toBeGreaterThan(0);      // numeric comparison
  expect([1, 2, 3]).toContain(2);        // arrays and strings
  expect('hello world').toContain('world');
  expect({ a: 1 }).toEqual({ a: 1 });    // deep equality
});

values.test.js

const { test, expect } = require('@mobilewright/test');

test('plain value assertions', async ({ screen }) => {
  const count = await screen.getByRole('listitem').count();

  expect(count).toBe(5);                 // strict equality
  expect(count).toBeGreaterThan(0);      // numeric comparison
  expect([1, 2, 3]).toContain(2);        // arrays and strings
  expect('hello world').toContain('world');
  expect({ a: 1 }).toEqual({ a: 1 });    // deep equality
});

Tip: Rule of thumb: assert on locators whenever possible — they auto-wait and make tests stable. Only use value assertions for data you have already read out of the app.

Mobilewright Intermediate Assertions expect

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Written by PV