Assertions

Lupa doesn't force a specific assertion library onto you. You are free to use any browser-compatible assertion library you like (such as Chai, expect, or standard Node assert polyfills) simply by importing them directly into your test files.

However, Lupa does ship with an officially supported, first-party assertion plugin: @pawel-up/lupa/assert. It provides a clean, chainable API built on top of Chai, and seamlessly integrates with Lupa's test context.

Installing the Assert Plugin

To use the built-in assert library, you need to register it as a test plugin inside your runner configuration.

Update your lupa.config.ts file to include @pawel-up/lupa/assert in the testPlugins array:

import { defineConfig } from '@pawel-up/lupa/runner'
import { spec } from '@pawel-up/lupa/reporters'

export default defineConfig({
  suites: [
    {
      name: 'unit',
      files: ['tests/**/*.test.ts'],
    },
  ],
  testPlugins: ['@pawel-up/lupa/assert'], // Register the assert plugin
  reporters: {
    activated: ['progress'],
  },
})

TypeScript Configuration

Because plugins extend the base TestContext dynamically at runtime, TypeScript doesn't automatically know that the assert property exists on the context object.

To tell the TypeScript compiler about the assert property, you must use Module Augmentation. You can place this declaration directly at the bottom of your lupa.config.ts file, or inside a dedicated global.d.ts file in your project.

import type { Assert } from '@pawel-up/lupa/assert'

// ... your defineConfig() logic ...

declare module '@pawel-up/lupa/testing' {
  interface TestContext {
    assert: Assert
  }
}

Once you've added this augmentation, your editor will provide full autocomplete and type safety for the assert object inside all of your tests.

Using Assertions

With the plugin registered and TypeScript configured, the assert object is injected into the context of every test.

import { test } from '@pawel-up/lupa/testing'

test('validates user input', ({ assert }) => {
  const username = 'pawel'
  
  // You now have full autocomplete on the assert object!
  assert.equal(username, 'pawel')
  assert.isString(username)
  assert.lengthOf(username, 5)
})

For a comprehensive list of all available assertion methods, you can rely on your IDE's autocomplete, as the Assert type provides extensive JSDoc descriptions and examples for every available assertion.

Core Assertions API

The Assert plugin of Lupa is built on top of the Chai.js assert package and ships with the following methods:

plan

Plan assertions to expect by the end of this test This method is used to declare the number of assertions you expect to run in a test. If the number of assertions that actually run does not match the planned number, the test will fail.

assert

Assert an expression to be truthy. Optionally define the error message

assert(isTrue(foo))
assert(foo === 'bar')
assert(age > 18, 'Not allowed to enter the club')

fail

Throws a failure. The actual and expected values are not compared. They are available as properties on the AssertionError.

assert.fail() // fail
assert.fail('Error message for the failure')

isOk

Assert the value is truthy

assert.isOk({ hello: 'world' }) // passes
assert.isOk(null) // fails

ok

Assert the value is truthy Alias for isOk

assert.ok({ hello: 'world' }) // passes
assert.ok(null) // fails

isNotOk

Assert the value is falsy

assert.isNotOk({ hello: 'world' }) // fails
assert.isNotOk(null) // passes

notOk

Assert the value is falsy Alias for isNotOk

assert.notOk({ hello: 'world' }) // fails
assert.notOk(null) // passes

equal

Assert two values are equal but not strictly. The comparison is same as "foo == bar".

assert.equal(3, 3) // passes
assert.equal(3, '3') // passes
assert.equal(Symbol.for('foo'), Symbol.for('foo')) // passes

notEqual

Assert two values are not equal. The comparison is same as "foo != bar".

assert.notEqual(3, 2) // passes
assert.notEqual(3, '2') // passes
assert.notEqual(Symbol.for('foo'), Symbol.for('bar')) // passes

strictEqual

Assert two values are strictly equal. The comparison is same as "foo === bar".

assert.equal(3, 3) // passes
assert.equal(3, '3') // fails
assert.equal(Symbol.for('foo'), Symbol.for('foo')) // passes

notStrictEqual

Assert two values are not strictly equal. The comparison is same as "foo !== bar".

assert.notStrictEqual(3, 2) // passes
assert.notStrictEqual(3, '2') // fails
assert.notStrictEqual(Symbol.for('foo'), Symbol.for('bar')) // passes

deepEqual

Assert two values are deeply equal. The order of items in an array should be same for the assertion to pass.

assert.deepEqual({ a: 1, b: 2 }, { a: 1, b: 2 }) // passes
assert.deepEqual({ b: 2, a: 1 }, { a: 1, b: 2 }) // passes
assert.deepEqual([1, 2], [1, 2]) // passes
assert.deepEqual([1, 2], [2, 1]) // fails
assert.deepEqual(/a/, /a/) // passes
assert.deepEqual(
new Date('2020 01 22'),
new Date('2020 01 22')
) // passes

notDeepEqual

Assert two values are not deeply equal.

assert.notDeepEqual({ a: 1, b: 2 }, { a: 1, b: '2' }) // passes
assert.notDeepEqual([1, 2], [2, 1]) // passes
assert.notDeepEqual(
new Date('2020 01 22'),
new Date('2020 01 23')
) // passes

isAbove

Assert if the actual Date is above the expected Date.

assert.isAbove(new Date('2020 12 20'), new Date('2020 12 18')) // passes

isAtLeast

Assert if the actual value is above or same as the expected value.

assert.isAtLeast(new Date('2020 12 20'), new Date('2020 12 20')) // passes

isBelow

Assert if the actual value is below the expected value.

assert.isBelow(new Date('2020 12 20'), new Date('2020 12 24')) // passes

isAtMost

Assert if the actual value is below or same as the expected value.

assert.isAtMost(new Date('2020 12 20'), new Date('2020 12 20')) // passes

isTrue

Assert the value is a boolean (true).

assert.isTrue(true) // passes
assert.isTrue(false) // fails
assert.isTrue(1) // fails
assert.isTrue('foo') // fails

isNotTrue

Assert the value is anything, but not true

assert.isNotTrue(true) // fails
assert.isNotTrue(false) // passes
assert.isNotTrue(1) // passes
assert.isNotTrue('foo') // passes

isFalse

Assert the value is boolean (false)

assert.isFalse(false) // passes
assert.isFalse(true) // fails
assert.isFalse(0) // fails
assert.isFalse(null) // fails

isNotFalse

Assert the value is anything but not false

assert.isNotFalse(false) // fails
assert.isNotFalse(true) // passes
assert.isNotFalse(null) // passes
assert.isNotFalse(undefined) // passes

isNull

Assert the value is null

assert.isNull(null) // passes
assert.isNull(true) // fails
assert.isNull(false) // fails
assert.isNull('foo') // fails

isNotNull

Assert the value is anything but not null

assert.isNotNull(null) // fails
assert.isNotNull(true) // passes
assert.isNotNull(false) // passes
assert.isNotNull('foo') // passes

isNaN

Assert the value is NaN

assert.isNaN(NaN) // passes
assert.isNaN(Number('hello')) // passes
assert.isNaN(true) // fails
assert.isNaN(false) // fails
assert.isNaN(null) // fails

isNotNaN

Assert the value is anything, but not NaN

assert.isNotNaN(NaN) // fails
assert.isNotNaN(Number('hello')) // fails
assert.isNotNaN(true) // passes
assert.isNotNaN(false) // passes
assert.isNotNaN(null) // passes

exists

Asserts the value is not "null" or "undefined"

assert.exists(false) // passes
assert.exists(0) // passes
assert.exists('') // passes
assert.exists(null) // fails
assert.exists(undefined) // fails

notExists

Asserts the value is "null" or "undefined"

assert.notExists(null) // passes
assert.notExists(undefined) // passes
assert.notExists('') // fails
assert.notExists(false) // fails
assert.notExists(0) // fails

isUndefined

Asserts the value is explicitly "undefined"

assert.isUndefined(undefined) // passes
assert.isUndefined(false) // fails
assert.isUndefined(0) // fails
assert.isUndefined('') // fails
assert.isUndefined(null) // fails

isDefined

Asserts the value is anything, but not "undefined"

assert.isDefined(undefined) // fails
assert.isDefined(0) // passes
assert.isDefined(false) // passes
assert.isDefined('') // passes
assert.isDefined(null) // passes

isFunction

Assert the value is a function

assert.isFunction(function foo () {}) // passes
assert.isFunction(() => {}) // passes
assert.isFunction(class Foo {}) // passes

isNotFunction

Assert the value is not a function

assert.isNotFunction({}) // passes
assert.isNotFunction(null) // passes
assert.isNotFunction(() => {}) // fails

isObject

Assert the value to a valid object literal

assert.isObject({}) // passes
assert.isObject(new SomeClass()) // passes
assert.isObject(null) // fails
assert.isObject([]) // fails

isNotObject

Assert the value to not be an object literal

assert.isNotObject(null) // passes
assert.isNotObject([]) // passes
assert.isNotObject({}) // fails
assert.isNotObject(new SomeClass()) // fails

isArray

Assert the value to be a valid array

assert.isArray([]) // passes
assert.isArray({}) // fails

isNotArray

Assert the value to not be an array

assert.isNotArray([]) // fails
assert.isNotArray({}) // passes

isString

Assert the value to be a string literal

assert.isString('') // passes
assert.isString(new String(true)) // passes
assert.isString(1) // fails

isNotString

Assert the value to not be a string literal

assert.isNotString(1) // passes
assert.isNotString('') // fails
assert.isNotString(new String(true)) // fails

isNumber

Assert the value to be a valid number

assert.isNumber(1) // passes
assert.isNumber(new Number('1')) // passes
assert.isNumber('1') // fails

isNotNumber

Assert the value to not be a valid number

assert.isNotNumber('1') // passes
assert.isNotNumber(1) // fails

isFinite

Assert the value to be a number and no NaN or Infinity

assert.isFinite(1) // passes
assert.isFinite(Infinity) // fails
assert.isFinite(NaN) // fails

isBoolean

Assert the value is a boolean

assert.isBoolean(true) // passes
assert.isBoolean(false) // passes
assert.isBoolean(1) // fails

isNotBoolean

Assert the value is anything, but not a boolean

assert.isNotBoolean(1) // passes
assert.isNotBoolean(false) // fails
assert.isNotBoolean(true) // fails

typeOf

Assert the typeof value matches the expected type

assert.typeOf({ foo: 'bar' }, 'object') // passes
assert.typeOf(['admin'], 'array') // passes
assert.typeOf(new Date(), 'date') // passes

notTypeOf

Assert the typeof value is not same as the expected type

assert.notTypeOf({ foo: 'bar' }, 'array') // passes
assert.notTypeOf(['admin'], 'string') // passes

instanceOf

Assert value to be an instance of the expected class

assert.instanceOf(new User(), User) // passes
assert.instanceOf(new User(), Function) // fails
class User extends BaseUser {}
assert.instanceOf(new User(), BaseUser) // passes

notInstanceOf

Assert value to NOT be an instance of the expected class

assert.notInstanceOf(new User(), Function) // passes
assert.notInstanceOf(new User(), User) // fails

include

Asserts that haystack includes needle.

notInclude

Asserts that haystack does not include needle.

deepInclude

Asserts that haystack includes needle. Deep equality is used.

notDeepInclude

Asserts that haystack does not include needle. Deep equality is used.

match

Assert the value to match the given regular expression

assert.match('foobar', /^foo/) // passes

notMatch

Assert the value to NOT match the given regular expression

assert.notMatch('foobar', /^foo/) // fails

property

Assert an object to contain a property

assert.property(
{ id: 1, username: 'virk' },
'id'
) // passes

notProperty

Assert an object to NOT contain a property

assert.notProperty(
{ id: 1, username: 'virk' },
'email'
) // passes

propertyVal

Assert an object property to match the expected value Use deepPropertyVal for deep comparing the value

assert.propertyVal(
{ id: 1, username: 'virk' },
'id',
1
) // passes
assert.propertyVal(
{ user: { id: 1 } },
'user',
{ id: 1 }
) // fails
@template T - Type of object.
@template V - Type of value.

notPropertyVal

Assert an object property to NOT match the expected value

assert.notPropertyVal(
{ id: 1, username: 'virk' },
'id',
22
) // passes
@template T - Type of object.
@template V - Type of value.

deepPropertyVal

Assert an object property to deeply match the expected value

assert.deepPropertyVal(
{ user: { id: 1 } },
'user',
{ id: 1 }
) // passes
@template T - Type of object.
@template V - Type of value.

notDeepPropertyVal

Assert an object property to NOT deeply match the expected value

assert.notDeepPropertyVal(
{ user: { id: 1 } },
'user',
{ email: 'foo@bar.com' }
) // passes
@template T - Type of object.
@template V - Type of value.

lengthOf

Assert length of an array, map or set to match the expected value

assert.lengthOf([1, 2, 3], 3)
assert.lengthOf(new Map([[1],[2]]), 2)
assert.lengthOf('hello world', 11)
@template T - Type of object.

properties

Assert the object has all of the expected properties

assert.properties(
{ username: 'virk', age: 22, id: 1 },
['id', 'age']
) // passes
@template T - Type of object.

anyProperties

Assert the object has any of the expected properties

assert.anyProperties(
{ username: 'virk', age: 22, id: 1 },
['id', 'name', 'dob']
) // passes
@template T - Type of object.

onlyProperties

Assert the object has only the expected properties. Extra properties will fail the assertion

assert.onlyProperties(
{ username: 'virk', age: 22, id: 1 },
['id', 'name', 'age']
) // passes
assert.onlyProperties(
{ username: 'virk', age: 22, id: 1 },
['id', 'name']
) // fails
@template T - Type of object.

notAnyProperties

Assert the object to not have any of the mentioned properties

assert.notAnyProperties(
{ id: 1, name: 'foo' },
['email', 'age']
) // passes
assert.notAnyProperties(
{ id: 1, name: 'foo' },
['email', 'id']
) // fails
@template T - Type of object.

notAllProperties

Assert the object to not have all of the mentioned properties

assert.notAllProperties(
{ id: 1, name: 'foo' },
['id', 'name', 'email']
) // passes
@template T - Type of object.

throws

Expect the function to throw an exception.

function foo() { throw new Error('blow up') }
assert.throws(foo) // passes

doesNotThrow

Expect the function to not throw an exception.

assert.doesNotThrow(() => {}) // passes

closeTo

Assert the value is closer to the expected value + delta

assert.closeTo(10, 6, 8) // passes
assert.closeTo(10, 6, 4) // passes
assert.closeTo(10, 20, 10) // passes

approximately

Assert the value is equal to the expected value +/- delta range

assert.approximately(10, 6, 8) // passes
assert.approximately(10, 6, 4) // passes
assert.approximately(10, 20, 10) // passes

sameMembers

Assert two arrays to have same members. The values comparison is same the assert.equal method. Use sameDeepMembers for deep comparison

assert.sameMembers(
[1, 2, 3],
[1, 2, 3]
) // passes
assert.sameMembers(
[1, { id: 1 }, 3],
[1, { id: 1 }, 3]
) // fails

notSameMembers

Assert two arrays to NOT have same members. The values comparison is same the assert.notEqual method. Use notSameDeepMembers for deep comparison

assert.notSameMembers(
[1, { id: 1 }, 3],
[1, { id: 1 }, 3]
) // passes
assert.notSameMembers(
[1, 2, 3],
[1, 2, 3]
) // fails

sameDeepMembers

Assert two arrays to have same members.

assert.sameDeepMembers(
[1, 2, 3],
[1, 2, 3]
) // passes
assert.sameDeepMembers(
[1, { id: 1 }, 3],
[1, { id: 1 }, 3]
) // passes

notSameDeepMembers

Assert two arrays to NOT have same members.

assert.notSameDeepMembers(
[1, { id: 1 }, 3],
[1, { id: 2 }, 3]
) // passes

sameOrderedMembers

Expect two arrays to have same members and in the same order. The values comparison is same the assert.equal method. Use sameDeepOrderedMembers for deep comparison

assert.sameOrderedMembers(
[1, 2, 3],
[1, 2, 3]
) // passes
assert.sameOrderedMembers(
[1, 3, 2],
[1, 2, 3]
) // fails

notSameOrderedMembers

Expect two arrays to either have different members or in different order The values comparison is same the assert.notEqual method. Use notSameDeepOrderedMembers for deep comparison

assert.notSameOrderedMembers(
[1, 2, 3],
[1, 2, 3]
) // passes
assert.notSameOrderedMembers(
[1, 3, 2],
[1, 2, 3]
) // fails

sameDeepOrderedMembers

Expect two arrays to have same members and in the same order. The values comparison is same the assert.deepEqual method.

assert.sameDeepOrderedMembers(
[1, { id: 1 }, { name: 'virk' }],
[1, { id: 1 }, { name: 'virk' }]
) // passes
assert.sameDeepOrderedMembers(
[1, { id: 1 }, { name: 'virk' }],
[1, { name: 'virk' }, { id: 1 }]
) // fails

notSameDeepOrderedMembers

Expect two arrays to either have different members or in different order The values comparison is same the assert.notDeepEqual method. Use notSameDeepOrderedMembers for deep comparison

assert.notSameDeepOrderedMembers(
[1, { id: 1 }, { name: 'virk' }],
[1, { name: 'virk' }, { id: 1 }]
) // passes
assert.notSameDeepOrderedMembers(
[1, { id: 1 }, { name: 'virk' }],
[1, { id: 1 }, { name: 'virk' }]
) // fails

includeMembers

Assert the expected array is a subset of a given array. The values comparison is same the assert.equal method. Use includeDeepMembers for deep comparison.

assert.includeMembers([1, 2, 4, 5], [1, 2]) // passes
assert.includeMembers([1, 2, 4, 5], [1, 3]) // fails

notIncludeMembers

Assert the expected array is NOT a subset of a given array. The values comparison is same the assert.notEqual method. Use notIncludeDeepMembers for deep comparison.

assert.notIncludeMembers([1, 2, 4, 5], [1, 3]) // passes
assert.notIncludeMembers([1, 2, 4, 5], [1, 2]) // fails

includeDeepMembers

Assert the expected array is a subset of a given array. The values comparison is same the assert.deepEqual method.

assert.includeDeepMembers(
[{ id: 1 }, { id: 2 }],
[{ id: 2 }]
) // passes
assert.includeDeepMembers(
[{ id: 1 }, { id: 2 }],
[{ id: 3 }]
) // fails

notIncludeDeepMembers

Assert the expected array is NOT a subset of a given array. The values comparison is same the assert.notDeepEqual method.

assert.notIncludeDeepMembers(
[{ id: 1 }, { id: 2 }],
[{ id: 3 }]
) // passes
assert.notIncludeDeepMembers(
[{ id: 1 }, { id: 2 }],
[{ id: 2 }]
) // fails

includeOrderedMembers

Assert the expected array is a subset of a given array and in the same order The values comparison is same the assert.equal method. Use includeDeepOrderedMembers for deep comparison.

assert.includeOrderedMembers(
[1, 2, 4, 5],
[1, 2, 4]
) // passes
assert.includeOrderedMembers(
[1, 2, 4, 5],
[1, 4, 2]
) // fails
assert.includeOrderedMembers(
[1, 2, 4, 5],
[1, 2, 5]
) // fails

notIncludeOrderedMembers

Assert the expected array is either not a subset of a given array or is not in the same order. The values comparison is same the assert.notEqual method. Use notIncludeDeepOrderedMembers for deep comparison.

assert.notIncludeOrderedMembers(
[1, 2, 4, 5],
[1, 4, 2]
) // passes
assert.notIncludeOrderedMembers(
[1, 2, 4, 5],
[1, 2, 5]
) // passes
assert.notIncludeOrderedMembers(
[1, 2, 4, 5],
[1, 2, 4]
) // fails

includeDeepOrderedMembers

Assert the expected array is a subset of a given array and in the same order The values comparison is same the assert.deepEqual method.

assert.includeDeepOrderedMembers(
[{ id: 1 }, { id: 2 }, { id: 4 }],
[{ id: 1 }, { id: 2 }]
) // passes
assert.includeDeepOrderedMembers(
[{ id: 1 }, { id: 2 }, { id: 4 }],
[{ id: 1 }, { id: 4 }]
) // fails
assert.includeDeepOrderedMembers(
[{ id: 1 }, { id: 2 }, { id: 4 }],
[{ id: 1 }, { id: 4 }, { id: 2 }]
) // fails

notIncludeDeepOrderedMembers

Assert the expected array is either not a subset of a given array or is not in the same order. The values comparison is same the assert.notDeepEqual method.

assert.notIncludeDeepOrderedMembers(
[{ id: 1 }, { id: 2 }, { id: 4 }],
[{ id: 1 }, { id: 4 }]
) // passes
assert.notIncludeDeepOrderedMembers(
[{ id: 1 }, { id: 2 }, { id: 4 }],
[{ id: 1 }, { id: 4 }, { id: 2 }]
) // passes
assert.notIncludeDeepOrderedMembers(
[{ id: 1 }, { id: 2 }, { id: 4 }],
[{ id: 1 }, { id: 2 }]
) // fails

isSealed

Assert the object is sealed.

assert.isSealed(Object.seal({})) // passes
assert.isSealed({}) // fails

sealed

Assert the object is sealed. Alias for isSealed

assert.sealed(Object.seal({})) // passes
assert.sealed({}) // fails

isNotSealed

Assert the object is not sealed.

assert.isNotSealed({}) // passes
assert.isNotSealed(Object.seal({})) // fails

notSealed

Assert the object is not sealed. Alias for isNotSealed

assert.notSealed({}) // passes
assert.notSealed(Object.seal({})) // fails

isFrozen

Assert the object is frozen.

assert.isFrozen(Object.freeze({})) // passes
assert.isFrozen({}) // fails

frozen

Assert the object is frozen. Alias for isFrozen

assert.frozen(Object.freeze({})) // passes
assert.frozen({}) // fails

isNotFrozen

Assert the object is not frozen.

assert.isNotFrozen({}) // passes
assert.isNotFrozen(Object.freeze({})) // fails

notFrozen

Assert the object is not frozen. Alias for isNotFrozen

assert.notFrozen({}) // passes
assert.notFrozen(Object.freeze({})) // fails

isEmpty

Assert value to be empty

assert.isEmpty([]) // passes
assert.isEmpty({}) // passes
assert.isEmpty('') // passes

empty

Assert value to be empty Alias for isEmpty

assert.empty([]) // passes
assert.empty({}) // passes
assert.empty('') // passes

isNotEmpty

Assert value to not be empty

assert.isNotEmpty([1, 2]) // passes
assert.isNotEmpty({ foo: 'bar' }) // passes
assert.isNotEmpty('hello') // passes

notEmpty

Assert value to not be empty Alias for isNotEmpty

assert.notEmpty([1, 2]) // passes
assert.notEmpty({ foo: 'bar' }) // passes
assert.notEmpty('hello') // passes

containSubset

Assert an array or an object to contain a subset of the expected value. Useful for testing API responses.

assert.containSubset(
{ id: 1, created_at: Date },
{ id: 1 }
) // passes
assert.containSubset(
[
{ id: 1, created_at: Date },
{ id: 2, created_at: Date }
],
[{ id: 1 }, { id: 2 }]
) // passes

doesNotContainSubset

Assert an array or an object does not contain a subset of the expected value. Useful for testing API responses.

assert.doesNotContainSubset(
{ id: 1, created_at: Date },
{ name: 'foo' }
) // passes
assert.doesNotContainSubset(
[
{ id: 1, created_at: Date },
{ id: 2, created_at: Date }
],
[{ name: 'foo' }, { id: 2 }]
) // passes

containsSubset

Assert an array or an object to contain a subset of the expected value. Useful for testing API responses.

assert.containsSubset(
{ id: 1, created_at: Date },
{ id: 1 }
) // passes
assert.containsSubset(
[
{ id: 1, created_at: Date },
{ id: 2, created_at: Date }
],
[{ id: 1 }, { id: 2 }]
) // passes

notContainsSubset

Assert an array or an object to not contain a subset of the expected value.

assert.notContainsSubset(
{ id: 1, created_at: Date },
{ email: 'foo@bar.com' }
) // passes

oneOf

Assert the value is available in the provided list.

assert.oneOf('foo', ['foo', 'bar', 'baz']) // passes
assert.oneOf('foo', ['bar', 'baz']) // fails

DOM Assertions API

Lupa also ships with powerful built-in DOM assertions that make testing UI components a breeze. They are accessible under the assert.dom property.

dom.hasText

Asserts that an element contains the specified text content.

assert.dom.hasText(element, 'Hello World')

dom.hasClass

Asserts that an element has the specified class name.

assert.dom.hasClass(element, 'active')

dom.hasAttribute

Asserts that an element has a specific attribute, optionally checking its value.

assert.dom.hasAttribute(element, 'disabled')
assert.dom.hasAttribute(element, 'type', 'button')

dom.isVisible

Asserts that an element is visible in the DOM (occupies space).

assert.dom.isVisible(element)

dom.isFocused

Asserts that an element is currently focused (document.activeElement).

assert.dom.isFocused(inputElement)

dom.hasTagName

Asserts that an element has the specified tag name.

assert.dom.hasTagName(element, 'button')

dom.hasStyle

Asserts that an element has the specified computed style property and value.

assert.dom.hasStyle(element, 'color', 'rgb(255, 0, 0)')

dom.equal / dom.notEqual

Asserts that an element's outer DOM matches (or does not match) the expected HTML string semantically.

assert.dom.equal(element, '<button class="btn">Click me</button>')

dom.lightEqual / dom.notLightEqual

Asserts that an element's Light DOM (innerHTML) matches (or does not match) the expected HTML string semantically.

assert.dom.lightEqual(element, '<span>Inner content</span>')

dom.shadowEqual / dom.notShadowEqual

Asserts that an element's Shadow DOM matches (or does not match) the expected HTML string semantically.

assert.dom.shadowEqual(element, '<style>.host {}</style><div></div>')