1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
|
# Page objects in GitLab QA
In GitLab QA we are using a known pattern, called _Page Objects_.
This means that we have built an abstraction for all pages in GitLab that we use
to drive GitLab QA scenarios. Whenever we do something on a page, like filling
in a form, or clicking a button, we do that only through a page object
associated with this area of GitLab.
For example, when GitLab QA test harness signs in into GitLab, it needs to fill
in a user login and user password. In order to do that, we have a class, called
`Page::Main::Login` and `sign_in_using_credentials` methods, that is the only
piece of the code, that has knowledge about `user_login` and `user_password`
fields.
## Why do we need that?
We need page objects, because we need to reduce duplication and avoid problems
whenever someone changes some selectors in GitLab's source code.
Imagine that we have a hundred specs in GitLab QA, and we need to sign into
GitLab each time, before we make assertions. Without a page object one would
need to rely on volatile helpers or invoke Capybara methods directly. Imagine
invoking `fill_in :user_login` in every `*_spec.rb` file / test example.
When someone later changes `t.text_field :login` in the view associated with
this page to `t.text_field :username` it will generate a different field
identifier, what would effectively break all tests.
Because we are using `Page::Main::Login.perform(&:sign_in_using_credentials)`
everywhere, when we want to sign into GitLab, the page object is the single
source of truth, and we will need to update `fill_in :user_login`
to `fill_in :user_username` only in a one place.
## What problems did we have in the past?
We do not run QA tests for every commit, because of performance reasons, and
the time it would take to build packages and test everything.
That is why when someone changes `t.text_field :login` to
`t.text_field :username` in the _new session_ view we won't know about this
change until our GitLab QA nightly pipeline fails, or until someone triggers
`package-and-qa-manual` action in their merge request.
Obviously such a change would break all tests. We call this problem a _fragile
tests problem_.
In order to make GitLab QA more reliable and robust, we had to solve this
problem by introducing coupling between GitLab CE / EE views and GitLab QA.
## How did we solve fragile tests problem?
Currently, when you add a new `Page::Base` derived class, you will also need to
define all selectors that your page objects depends on.
Whenever you push your code to CE / EE repository, `qa:selectors` sanity test
job is going to be run as a part of a CI pipeline.
This test is going to validate all page objects that we have implemented in
`qa/page` directory. When it fails, you will be notified about missing
or invalid views / selectors definition.
## How to properly implement a page object?
We have built a DSL to define coupling between a page object and GitLab views
it is actually implemented by. See an example below.
```ruby
module Page
module Main
class Login < Page::Base
view 'app/views/devise/passwords/edit.html.haml' do
element :password_field
element :password_confirmation
element :change_password_button
end
view 'app/views/devise/sessions/_new_base.html.haml' do
element :login_field
element :password_field
element :sign_in_button
end
# ...
end
end
end
```
### Defining Elements
The `view` DSL method will correspond to the rails View, partial, or vue component that renders the elements.
The `element` DSL method in turn declares an element for which a corresponding
`data-qa-selector=element_name_snaked` data attribute will need to be added to the view file.
You can also define a value (String or Regexp) to match to the actual view
code but **this is deprecated** in favor of the above method for two reasons:
- Consistency: there is only one way to define an element
- Separation of concerns: QA uses dedicated `data-qa-*` attributes instead of reusing code
or classes used by other components (e.g. `js-*` classes etc.)
```ruby
view 'app/views/my/view.html.haml' do
### Good ###
# Implicitly require the CSS selector `[data-qa-selector="logout_button"]` to be present in the view
element :logout_button
### Bad ###
## This is deprecated and forbidden by the `QA/ElementWithPattern` RuboCop cop.
# Require `f.submit "Sign in"` to be present in `my/view.html.haml
element :my_button, 'f.submit "Sign in"' # rubocop:disable QA/ElementWithPattern
## This is deprecated and forbidden by the `QA/ElementWithPattern` RuboCop cop.
# Match every line in `my/view.html.haml` against
# `/link_to .* "My Profile"/` regexp.
element :profile_link, /link_to .* "My Profile"/ # rubocop:disable QA/ElementWithPattern
end
```
### Adding Elements to a View
Given the following elements...
```ruby
view 'app/views/my/view.html.haml' do
element :login_field
element :password_field
element :sign_in_button
end
```
To add these elements to the view, you must change the rails View, partial, or vue component by adding a `data-qa-selector` attribute
for each element defined.
In our case, `data-qa-selector="login_field"`, `data-qa-selector="password_field"` and `data-qa-selector="sign_in_button"`
**app/views/my/view.html.haml**
```haml
= f.text_field :login, class: "form-control top", autofocus: "autofocus", autocapitalize: "off", autocorrect: "off", required: true, title: "This field is required.", data: { qa_selector: 'login_field' }
= f.password_field :password, class: "form-control bottom", required: true, title: "This field is required.", data: { qa_selector: 'password_field' }
= f.submit "Sign in", class: "btn btn-success", data: { qa_selector: 'sign_in_button' }
```
Things to note:
- The name of the element and the qa_selector must match and be snake_cased
- If the element appears on the page unconditionally, add `required: true` to the element. See
[Dynamic element validation](dynamic_element_validation.md)
- You may see `.qa-selector` classes in existing Page Objects. We should prefer the [`data-qa-selector`](#data-qa-selector-vs-qa-selector)
method of definition over the `.qa-selector` CSS class
### `data-qa-selector` vs `.qa-selector`
> Introduced in GitLab 12.1
There are two supported methods of defining elements within a view.
1. `data-qa-selector` attribute
1. `.qa-selector` class
Any existing `.qa-selector` class should be considered deprecated
and we should prefer the `data-qa-selector` method of definition.
### Dynamic element selection
> Introduced in GitLab 12.5
A common occurrence in automated testing is selecting a single "one-of-many" element.
In a list of several items, how do you differentiate what you are selecting on?
The most common workaround for this is via text matching. Instead, a better practice is
by matching on that specific element by a unique identifier, rather than by text.
We got around this by adding the `data-qa-*` extensible selection mechanism.
#### Examples
**Example 1**
Given the following Rails view (using GitLab Issues as an example):
```haml
%ul.issues-list
- @issues.each do |issue|
%li.issue{data: { qa_selector: 'issue', qa_issue_title: issue.title } }= link_to issue
```
We can select on that specific issue by matching on the Rails model.
```ruby
class Page::Project::Issues::Index < Page::Base
def has_issue?(issue)
has_element? :issue, issue_title: issue
end
end
```
In our test, we can validate that this particular issue exists.
```ruby
describe 'Issue' do
it 'has an issue titled "hello"' do
Page::Project::Issues::Index.perform do |index|
expect(index).to have_issue('hello')
end
end
end
```
**Example 2**
*By an index...*
```haml
%ol
- @some_model.each_with_index do |model, idx|
%li.model{ data: { qa_selector: 'model', qa_index: idx } }
```
```ruby
expect(the_page).to have_element(:model, index: 1) #=> select on the first model that appears in the list
```
### Exceptions
In some cases it might not be possible or worthwhile to add a selector.
Some UI components use external libraries, including some maintained by third parties.
Even if a library is maintained by GitLab, the selector sanity test only runs
on code within the GitLab project, so it's not possible to specify the path for
the view for code in a library.
In such rare cases it's reasonable to use CSS selectors in page object methods,
with a comment explaining why an `element` can't be added.
## Running the test locally
During development, you can run the `qa:selectors` test by running
```shell
bin/qa Test::Sanity::Selectors
```
from within the `qa` directory.
## Where to ask for help?
If you need more information, ask for help on `#quality` channel on Slack
(internal, GitLab Team only).
If you are not a Team Member, and you still need help to contribute, please
open an issue in GitLab CE issue tracker with the `~QA` label.
|