Style guide for writing end-to-end tests
This document describes the conventions used at GitLab for writing End-to-end (E2E) tests using the GitLab QA project.
This guide is an extension of the primary testing standards and style guidelines. If this guide defines a rule that contradicts the primary guide, this guide takes precedence.
click_
versus go_to_
click_
?
When to use When selecting a single link to navigate, use click_
.
For example:
def click_add_badge_button
click_element 'add-badge-button'
end
From a testing perspective, if we want to check that selecting a link, or a button (a single interaction) is working as intended, we would want the test to read as:
- Select a certain element
- Verify the action took place
go_to_
?
When to use When interacting with multiple elements to go to a page, use go_to_
.
For example:
def go_to_applications
click_element('nav-item-link', submenu_item: 'Applications')
end
go_to_
fits the definition of interacting with multiple elements very well given it's more of a meta-navigation action that includes multiple interactions.
Notice that in the above example, before selecting the 'nav-item-link'
, another element is hovered over.
We can create these methods as helpers to abstract multi-step navigation.
Element naming convention
When adding new elements to a page, it's important that we have a uniform element naming convention.
We follow a simple formula roughly based on Hungarian notation.
Formula: element :<descriptor>_<type>
-
descriptor
: The natural-language description of what the element is. On the login page, this could beusername
, orpassword
. -
type
: A generic control on the page that can be seen by a user.-button
-checkbox
-
-container
: an element that includes other elements, but doesn't present visible content itself. For example, an element that has a third-party editor inside it, but which isn't the editor itself and so doesn't include the editor's content. -
-content
: any element that contains text, images, or any other content displayed to the user. -dropdown
-
-field
: a text input element. -link
-
-modal
: a popup modal dialog, for example, a confirmation prompt. -
-placeholder
: a temporary element that appears while content is loading. For example, the elements that are displayed instead of discussions while the discussions are being fetched. -radio
-tab
-menu_item
NOTE: If none of the listed types are suitable, open a merge request to add an appropriate type to the list.
Examples
Good
view '...' do
element 'edit-button'
element 'notes-tab'
element 'squash-checkbox'
element 'username-field'
element 'issue-title-content'
end
Bad
view '...' do
# `'-confirmation'` should be `'-field'`. what sort of confirmation? a checkbox confirmation? no real way to disambiguate.
# an appropriate replacement would be `element 'password-confirmation-field'`
element 'password-confirmation'
# `'clone-options'` is too vague. If it's a dropdown menu, it should be `'clone-dropdown'`.
# If it's a checkbox, it should be `'clone-checkbox'`
element 'clone-options'
# how is this url being displayed? is it a textbox? a simple span?
# If it is content on the page, it should be `'ssh-clone-url-content'`
element 'ssh-clone-url'
end
Block argument naming
To have a standard on what we call pages and resources when using the .perform
method,
we use the name of the page object in snake_case
(all lowercase, with words separated by an underscore). See good and bad examples below.
While we prefer to follow the standard in most cases, it is also acceptable to
use common abbreviations (for example, mr
) or other alternatives, as long as
the name is not ambiguous. This can include appending _page
if it helps to
avoid confusion or make the code more readable. For example, if a page object is
named New
, it could be confusing to name the block argument new
because that
is used to instantiate objects, so new_page
would be acceptable.
We chose not to use page
because that would shadow the
Capybara DSL, potentially leading to confusion and bugs.
Examples
Good
Page::Project::Members.perform do |members|
members.do_something
end
Resource::MergeRequest.fabricate! do |merge_request|
merge_request.do_something_else
end
Resource::MergeRequest.fabricate! do |mr|
mr.do_something_else
end
Page::Project::New.perform do |new_page|
new_page.do_something
end
Bad
Page::Project::Members.perform do |project_settings_members_page|
project_settings_members_page.do_something
end
Page::Project::New.perform do |page|
page.do_something
end
Besides the advantage of having a standard in place, by following this standard we also write shorter lines of code.