Page object framework for end-to-end testing in Playwright.
npm install lariat
Page object framework for end-to-end testing in Playwright.
``sh`
npm install lariat
`sh`
yarn add lariat
At the core of Lariat is the Collection class. This class is used to represent
a collection of elements in a page or section of a page and can include
associated utility methods for interacting with those elements.
To create your own collections, simply create a class which extends the
Collection class. You can then define elements using the Collection.el()
method which we will explore more in a moment.
`ts
import Collection from 'lariat'
class TodoPage extends Collection
input = this.el('#todo-input')
}
`
With your collection defined, you can instantiate it in your test to access the
elements.
`ts`
test('create a todo', async ({ page }) => {
const todoPage = new TodoPage(page)
await todoPage.input.fill('Finish the website')
})
Elements are defined in collections using the Collection.el() method.
`ts`
class TodoPage extends Collection
saveButton = this.el('#save-button')
}
Elements are represented using Playwright
locators .
`ts`
const todoPage = new TodoPage(page)
await todoPage.saveButton.click()
The has and hasText locator options can be passed to Collection.el() to
match elements that contain a given locator or text.
`ts`
class TodoPage extends Collection
buttonWithIcon = this.el('button', { has: this.el('svg') })
saveButton = this.el('button', { hasText: 'Save' })
}
Because collections in Lariat are plain JavaScript classes, you can easily
create elements with dynamic selectors. Consider a todo list where we find an
item based on it's name. Our collection might look something like this:
`ts#todo-item[data-name="${name}"]
class TodoPage extends Collection
item = (name: string) => this.el()
}
const todoPage = new TodoPage(page)
const item = todoPage.item('Finish the website')
await item.click()
`
Sometimes, the DOM structure of a page might not match the visual structure
exactly. For example, if you use React's createPortal function you can renderportal
an element outside the main React tree. To support these use cases, Lariat
allows you to pass a option to Collection.el() to indicate that theroot
element should not be based off the element.
`ts`
class TodoPage extends Collection
modal = this.el('#modal', { portal: true })
}
Because collections are plain JavaScript classes, you can easily add utility
methods to your collections.
`ts
class TodoPage extends Collection
input = this.el('#todo-input')
saveButton = this.el('#save-button')
async create(name: string) {
await this.input.fill(name)
await this.input.click()
}
}
const todoPage = new TodoPage(page)
await todoPage.create('Finish the website')
`
So far, we've shown examples of simple collections, but Lariat also gives you
the ability to nest collections inside each other. With this approach, you can
create a page object structure that more closely resembles your page layout.
To nest a collection, use the Collection.nest() method and pass the nested
collection class and the root of the nested collection.
`ts
class TodoPage extends Collection
field = this.nest(TextField, '#todo-field')
}
const todoPage = new TodoPage(page)
await todoPage.field.input.fill('Finish the website')
`
If your nested collection is used merely to group a set of related elements
together, you can use the parent's root property as the root of the child
collection.
`ts`
class TodoPage extends Collection
field = this.nest(TextField, this.root)
}
If your nested collection exists outside the DOM structure of the parent
collection, you can use the parent's frame property as the root of the childportal
collection. This behaves very similarly to the option forCollection.el().
`ts`
class TodoPage extends Collection
modal = this.nest(Modal, this.frame)
}
In some cases, you may have a nested collection where multiple instances exist
on the page. For example, a todo list may contain multiple todo items each of
which are represented as a collection. To make these scenarios easier, Lariat
provides first, last, and nth methods which will return a new instance of
the nested collection scoped to that specific item.
`ts
class TodoPage extends Collection
item = this.nest(TodoItem, '.todo-item')
}
const todoPage = new TodoPage(page)
const firstItem = todoPage.item.first()
const secondItem = todoPage.item.nth(1)
const lastItem = todoPage.item.last()
`
Lariat has utilities for working with frames thanks to Playwright's
FrameLocator.
The simplest way to access an element in a frame is by using the frame optionCollection.el
of . Simply pass a string as a selector for the frame and Lariat
will take care of the rest.
`ts`
class FramePage extends Collection
frameHeader = this.el('h1', { frame: '#my-frame' })
}
However, if you need to access multiple elements in a frame, you can use
Collection.nest with a FrameLocator.
`ts
class MyFrame extends Collection
header = this.el('h1')
content = this.el('main')
}
class FramePage extends Collection
myFrame = this.nest(MyFrame, this.page.frameLocator('#my-frame'))
}
`
You can use a similar method to instantiate collections with a FrameLocator as
the root.
`ts
class MyFrame extends Collection
header = this.el('h1')
content = this.el('main')
}
new MyFrame(page.frameLocator('#my-frame'))
`
Lariat makes it easy to access the page or frame that a collection is associated
with.
`ts
class TodoPage extends Collection {
input = this.el('#todo-input')
}
const todoPage = new TodoPage(page.locator('#my-page'))
await todoPage.frame.goto('https://google.com')
await todoPage.page.mouse.down()
``