Selectors
The WebDriver Protocol provides several selector strategies to query an element. WebdriverIO simplifies them to keep selecting elements simple. Please note that even though the command to query elements is called $ and $$, they have nothing to do with jQuery or the Sizzle Selector Engine.
While there are so many different selectors available, only a few of them provide a resilient way to find the right element. For example, given the following button:
<button
id="main"
class="btn btn-large"
name="submission"
role="button"
data-testid="submit"
>
Submit
</button>
We do and do not recommend the following selectors:
| Selector | Recommended | Notes |
|---|---|---|
$('button') | 🚨 Never | Worst - too generic, no context. |
$('.btn.btn-large') | 🚨 Never | Bad. Coupled to styling. Highly subject to change. |
$('#main') | ⚠️ Sparingly | Better. But still coupled to styling or JS event listeners. |
$(() => document.queryElement('button')) | ⚠️ Sparingly | Effective querying, complex to write. |
$('button[name="submission"]') | ⚠️ Sparingly | Coupled to the name attribute which has HTML semantics. |
$('button[data-testid="submit"]') | ✅ Good | Requires additional attribute, not connected to a11y. |
$('aria/Submit') or $('button=Submit') | ✅ Always | Best. Resembles how the user interacts with the page. |
CSS Query Selector
If not indicated otherwise, WebdriverIO will query elements using the CSS selector pattern, e.g.:
loading...
Link Text
To get an anchor element with a specific text in it, query the text starting with an equals (=) sign.
For example:
loading...
You can query this element by calling:
loading...
Partial Link Text
To find a anchor element whose visible text partially matches your search value,
query it by using *= in front of the query string (e.g. *=driver).
You can query the element from the example above by also calling:
loading...
Note: You can't mix multiple selector strategies in one selector. Use multiple chained element queries to reach the same goal, e.g.:
const elem = await $('header h1*=Welcome') // doesn't work!!!
// use instead
const elem = await $('header').$('*=driver')
Element with certain text
The same technique can be applied to elements as well.
For example, here's a query for a level 1 heading with the text "Welcome to my Page":
loading...
You can query this element by calling:
loading...
Or using query partial text:
loading...
The same works for id and class names:
loading...
You can query this element by calling:
loading...
Note: You can't mix multiple selector strategies in one selector. Use multiple chained element queries to reach the same goal, e.g.:
const elem = await $('header h1*=Welcome') // doesn't work!!!
// use instead
const elem = await $('header').$('h1*=Welcome')
Tag Name
To query an element with a specific tag name, use <tag> or <tag />.
loading...
You can query this element by calling:
loading...
Name Attribute
For querying elements with a specific name attribute you can either use a normal CSS3 selector or the provided name strategy from the JSONWireProtocol by passing something like [name="some-name"] as selector parameter:
loading...
loading...
Note: This selector strategy it deprecated and only works in old browser that are run by the JSONWireProtocol protocol or by using Appium.
xPath
It is also possible to query elements via a specific xPath.
An xPath selector has a format like //body/div[6]/div[1]/span[1].
loading...
You can query the second paragraph by calling:
loading...
You can use xPath to also traverse up and down the DOM tree:
loading...
Accessibility Name Selector
Query elements by their accessible name. The accessible name is what is announced by a screen reader when that element receives focus. The value of the accessible name can be both visual content or hidden text alternatives.
You can read more about this selector in our release blog post
Fetch by aria-label
loading...
loading...
Fetch by aria-labelledby
loading...
loading...
Fetch by content
loading...
loading...
Fetch by title
loading...
loading...
Fetch by alt property
loading...
loading...
ARIA - Role Attribute
For querying elements based on ARIA roles, you can directly specify role of the element like [role=button] as selector parameter:
loading...
loading...
ID Attribute
Locator strategy "id" is not supported in WebDriver protocol, one should use either CSS or xPath selector strategies instead to find elements using ID.
However some drivers (e.g. Appium You.i Engine Driver) might still support this selector.
Current supported selector syntaxes for ID are:
//css locator
const button = await $('#someid')
//xpath locator
const button = await $('//*[@id="someid"]')
//id strategy
// Note: works only in Appium or similar frameworks which supports locator strategy "ID"
const button = await $('id=resource-id/iosname')
JS Function
You can also use JavaScript functions to fetch elements using web native APIs. Of course, you can only do this inside a web context (e.g., browser, or web context in mobile).
Given the following HTML structure:
loading...
You can query the sibling element of #elem as follows:
loading...
Deep Selectors
Many frontend applications heavily rely on elements with shadow DOM. It is technically impossible to query elements within the shadow DOM without workarounds. The shadow$ and shadow$$ have been such workarounds that had their limitations. With the deep selector you can now query all elements within any shadow DOM using the common query command.
Given we have an application with the following structure:
With this selector you can query the <button /> element that is nested within another shadow DOM, e.g.:
loading...
Mobile Selectors
For hybrid mobile testing, it's important that the automation server is in the correct context before executing commands. For automating gestures, the driver ideally should be set to native context. But to select elements from the DOM, the driver will need to be set to the platform's webview context. Only then can the methods mentioned above can be used.
For native mobile testing, there is no switching between contexts, as you have to use mobile strategies and use the underlying device automation technology directly. This is especially useful when a test needs some fine-grained control over finding elements.
Android UiAutomator
Android’s UI Automator framework provides a number of ways to find elements. You can use the UI Automator API, in particular the UiSelector class to locate elements. In Appium you send the Java code, as a string, to the server, which executes it in the application’s environment, returning the element or elements.
const selector = 'new UiSelector().text("Cancel").className("android.widget.Button")'
const button = await $(`android=${selector}`)
await button.click()
Android DataMatcher and ViewMatcher (Espresso only)
Android's DataMatcher strategy provides a way to find elements by Data Matcher
const menuItem = await $({
"name": "hasEntry",
"args": ["title", "ViewTitle"]
})
await menuItem.click()
And similarly View Matcher
const menuItem = await $({
"name": "hasEntry",
"args": ["title", "ViewTitle"],
"class": "androidx.test.espresso.matcher.ViewMatchers"
})
await menuItem.click()
Android View Tag (Espresso only)
The view tag strategy provides a convenient way to find elements by their tag.
const elem = await $('-android viewtag:tag_identifier')
await elem.click()
iOS UIAutomation
When automating an iOS application, Apple’s UI Automation framework can be used to find elements.
This JavaScript API has methods to access to the view and everything on it.
const selector = 'UIATarget.localTarget().frontMostApp().mainWindow().buttons()[0]'
const button = await $(`ios=${selector}`)
await button.click()
You can also use predicate searching within iOS UI Automation in Appium to refine element selection even further. See here for details.
iOS XCUITest predicate strings and class chains
With iOS 10 and above (using the XCUITest driver), you can use predicate strings:
const selector = `type == 'XCUIElementTypeSwitch' && name CONTAINS 'Allow'`
const switch = await $(`-ios predicate string:${selector}`)
await switch.click()
And class chains:
const selector = '**/XCUIElementTypeCell[`name BEGINSWITH "D"`]/**/XCUIElementTypeButton'
const button = await $(`-ios class chain:${selector}`)
await button.click()
Accessibility ID
The accessibility id locator strategy is designed to read a unique identifier for a UI element. This has the benefit of not changing during localization or any other process that might change text. In addition, it can be an aid in creating cross-platform tests, if elements that are functionally the same have the same accessibility id.
- For iOS this is the
accessibility identifierlaid out by Apple here. - For Android the
accessibility idmaps to thecontent-descriptionfor the element, as described here.
For both platforms, getting an element (or multiple elements) by their accessibility id is usually the best method. It is also the preferred way over the deprecated name strategy.
const elem = await $('~my_accessibility_identifier')
await elem.click()
Class Name
The class name strategy is a string representing a UI element on the current view.
- For iOS it is the full name of a UIAutomation class, and will begin with
UIA-, such asUIATextFieldfor a text field. A full reference can be found here. - For Android it is the fully qualified name of a UI Automator class, such
android.widget.EditTextfor a text field. A full reference can be found here. - For Youi.tv it is the full name of a Youi.tv class, and will being with
CYI-, such asCYIPushButtonViewfor a push button element. A full reference can be found at You.i Engine Driver's GitHub page
// iOS example
await $('UIATextField').click()
// Android example
await $('android.widget.DatePicker').click()
// Youi.tv example
await $('CYIPushButtonView').click()
Chain Selectors
If you want to be more specific in your query, you can chain selectors until you've found the right
element. If you call element before your actual command, WebdriverIO starts the query from that element.
For example, if you have a DOM structure like:
<div class="row">
<div class="entry">
<label>Product A</label>
<button>Add to cart</button>
<button>More Information</button>
</div>
<div class="entry">
<label>Product B</label>
<button>Add to cart</button>
<button>More Information</button>
</div>
<div class="entry">
<label>Product C</label>
<button>Add to cart</button>
<button>More Information</button>
</div>
</div>
And you want to add product B to the cart, it would be difficult to do that just by using the CSS selector.
With selector chaining, it's way easier. Simply narrow down the desired element step by step:
await $('.row .entry:nth-child(2)').$('button*=Add').click()
Appium Image Selector
Using the -image locator strategy, it is possible to send an Appium an image file representing an element you want to access.
Supported file formats jpg,png,gif,bmp,svg
Full reference can be found here
const elem = await $('./file/path/of/image/test.jpg')
await elem.click()
Note: The way how Appium works with this selector is that it will internally make a (app)screenshot and use the provided image selector to verify if the element can be found in that (app)screenshot.
Be aware of the fact that Appium might resize the taken (app)screenshot to make it match the CSS-size of your (app)screen (this will happen on iPhones but also on Mac machines with a Retina display because the DPR is bigger than 1). This will result in not finding a match because the provided image selector might have been taken from the original screenshot. You can fix this by updating the Appium Server settings, see the Appium docs for the settings and this comment on a detailed explanation.
React Selectors
WebdriverIO provides a way to select React components based on the component name. To do this, you have a choice of two commands: react$ and react$$.
These commands allow you to select components off the React VirtualDOM and return either a single WebdriverIO Element or an array of elements (depending on which function is used).
Note: The commands react$ and react$$ are similar in functionality, except that react$$ will return all matching instances as an array of WebdriverIO elements, and react$ will return the first found instance.
Basic example
// index.jsx
import React from 'react'
import ReactDOM from 'react-dom'
function MyComponent() {
return (
<div>
MyComponent
</div>
)
}
function App() {
return (<MyComponent />)
}
ReactDOM.render(<App />, document.querySelector('#root'))
In the above code there is a simple MyComponent instance inside the application, which React is rendering inside a HTML element with id="root".
With the browser.react$ command, you can select an instance of MyComponent:
const myCmp = await browser.react$('MyComponent')
Now that you have the WebdriverIO element stored in myCmp variable, you can execute element commands against it.
Filtering components
The library that WebdriverIO uses internally allows to filter your selection by props and/or state of the component. To do so, you need to pass a second argument for props and/or a third argument for state to the browser command.
// index.jsx
import React from 'react'
import ReactDOM from 'react-dom'
function MyComponent(props) {
return (
<div>
Hello { props.name || 'World' }!
</div>
)
}
function App() {
return (
<div>
<MyComponent name="WebdriverIO" />
<MyComponent />
</div>
)
}
ReactDOM.render(<App />, document.querySelector('#root'))
If you want to select the instance of MyComponent that has a prop name as WebdriverIO, you can execute the command like so:
const myCmp = await browser.react$('MyComponent', {
props: { name: 'WebdriverIO' }
})
If you wanted to filter our selection by state, the browser command would looks something like so:
const myCmp = await browser.react$('MyComponent', {
state: { myState: 'some value' }
})
Dealing with React.Fragment
When using the react$ command to select React fragments, WebdriverIO will return the first child of that component as the component's node. If you use react$$, you will receive an array containing all the HTML nodes inside the fragments that match the selector.
// index.jsx
import React from 'react'
import ReactDOM from 'react-dom'
function MyComponent() {
return (
<React.Fragment>
<div>
MyComponent
</div>
<div>
MyComponent
</div>
</React.Fragment>
)
}
function App() {
return (<MyComponent />)
}
ReactDOM.render(<App />, document.querySelector('#root'))
Given the above example, this is how the commands would work:
await browser.react$('MyComponent') // returns the WebdriverIO Element for the first <div />
await browser.react$$('MyComponent') // returns the WebdriverIO Elements for the array [<div />, <div />]
Note: If you have multiple instances of MyComponent and you use react$$ to select these fragment components, you will be returned an one-dimensional array of all the nodes. In other words, if you have 3 <MyComponent /> instances, you will be returned an array with six WebdriverIO elements.
Custom Selector Strategies
If your app requires a specific way to fetch elements you can define yourself a custom selector strategy that you can use with custom$ and custom$$. For that register your strategy once in the beginning of the test:
browser.addLocatorStrategy('myCustomStrategy', (selector, root) => {
/**
* scope should be document if called on browser object
* and `root` if called on an element object
*/
const scope = root ? root : document
return scope.querySelectorAll(selector)
})
Given the following HTML snippet:
<div class="foobar" id="first">
<div class="foobar" id="second">
barfoo
</div>
</div>
Then use it by calling:
const elem = await browser.custom$('myCustomStrategy', '.foobar')
console.log(await elem.getAttribute('id')) // returns "first"
const nestedElem = await elem.custom$('myCustomStrategy', '.foobar')
console.log(await elem.getAttribute('id')) // returns "second"
Note: this only works in an web environment in which the execute command can be run.