Write assertions for native mobile apps tests

Overview

The goal of any automated test is to write assertions and ensure that the logic is working. In Nightwatch there are 2 ways in which assertions can be done:

  • app.assert.command(params)
  • expects

Assertions

All assertions are organised under the .assert namespace.

Text Related

Text Contains

app.assert.textContains(selector,'text') can be used to assert if an element’s text contains a certain text.


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` contains text Browser
app.assert.textContains({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'Browser');


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` contains text Browser
app.assert.textContains({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'Browser');

Text Equals

app.assert.textEquals(selector,'text') can be used to check if an element’s text exactly equals a particular text.


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` equals text BrowserStack
app.assert.textEquals({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'BrowserStack');


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` equals text BrowserStack
app.assert.textEquals({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'BrowserStack');

Text Matches

app.assert.textMatches(selector,'regex') can be used to check if the text of an element matches with the given regex.


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` is alphabet only
app.assert.textMatches({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'/^[a-z]+$/i');


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` is alphabet only
app.assert.textMatches({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'/^[a-z]+$/i');

Elements have attributes such as text,index,resource-id etc. These can be found using Appium inspector as shown below

Element attributes in Appium inspector

Assertions can be performed on attributes using the attribute related assertions.

Attribute Contains

app.assert.attributeContains(selector,'attribute','text') can be used to assert if an element’s attribute named attribute contains a certain text.


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` text attribute contains Browser
app.assert.attributeContains({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'text','Browser');


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` text attribute contains Browser
app.assert.attributeContains({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'text','Browser');

Attribute Equals

app.assert.attributeEquals(selector,'attribute','text') can be used to assert if an element’s attribute named attribute equals to a particular text.


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` text attribute equals BrowserStack
app.assert.attributeEquals({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'text','BrowserStack');


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` text attribute equals BrowserStack
app.assert.attributeEquals({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'text','BrowserStack');

Attribute Matches

app.assert.attributeMatches(selector,'attribute','regex') can be used to assert if an element’s attribute named attribute matches the given regex


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` text attribute only contains alphabets
app.assert.attributeMatches({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'text','/^[a-z]+$/i');


//Assert if the element with id `org.wikipedia:id/pcs-edit-section-title` text attribute only contains alphabets
app.assert.attributeMatches({selector: 'org.wikipedia:id/pcs-edit-section-title',locateStrategy: 'id'},'text','/^[a-z]+$/i');

Selected

Verify if an element is in a selected state with app.assert.selected(selector) method.


//Assert if the element with id `org.wikipedia:id/button` is selected
app.assert.selected({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});


//Assert if the element with id `org.wikipedia:id/button` is selected
app.assert.selected({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});

Enabled

Verify if an element is in an enabled state with app.assert.enabled(selector) method.


//Assert if the element with id `org.wikipedia:id/button` is enabled
app.assert.enabled({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});


//Assert if the element with id `org.wikipedia:id/button` is enabled
app.assert.enabled({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});

Visible

Verify if an element is visible with app.assert.visible(selector) method.


//Assert if the element with id `org.wikipedia:id/button` is visible
app.assert.visible({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});


//Assert if the element with id `org.wikipedia:id/button` is visible
app.assert.visible({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});

Elements count

To verify the count of elements with a particular selector use the app.assert.elementsCount() API


//Assert if the element with id `org.wikipedia:id/list_item` has a count of 7
app.assert.elementsCount({selector: 'org.wikipedia:id/list_item',locateStrategy: 'id'},7);


//Assert if the element with id `org.wikipedia:id/list_item` has a count of 7
app.assert.elementsCount({selector: 'org.wikipedia:id/list_item',locateStrategy: 'id'},7);

Present

Verify if an element is present in the render tree with app.assert.elementsPresent(selector) method.


//Assert if the element with id `org.wikipedia:id/button` is present in the render tree
app.assert.elementsPresent({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});


//Assert if the element with id `org.wikipedia:id/button` is present in the render tree
app.assert.elementsPresent({selector: 'org.wikipedia:id/button',locateStrategy: 'id'});

Chai Expects

In addition to the assertions under the .assert namespace,Nightwatch also supports BDD style expect assertions. E.g.:


app.appium.getCurrentActivity(function(activity){
    expect(activity.value).to.equal('.page.PageActivity')
})


app.appium.getCurrentActivity(function(activity){
    expect(activity.value).to.equal('.page.PageActivity')
})

The way to use expects with mobile apps is the same as web. Please refer to the guide for more details.

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