Commit 0396c852 authored by Dmitriy Zaporozhets's avatar Dmitriy Zaporozhets

Merge branch 'rs-testing-guide' into 'master'

First pass at a Testing styleguide

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/14121

[ci skip]

See merge request !3465
parents 940b27ec 6ffda88c
...@@ -448,7 +448,7 @@ merge request: ...@@ -448,7 +448,7 @@ merge request:
- multi-line method chaining style **Option B**: dot `.` on previous line - multi-line method chaining style **Option B**: dot `.` on previous line
- string literal quoting style **Option A**: single quoted by default - string literal quoting style **Option A**: single quoted by default
1. [Rails](https://github.com/bbatsov/rails-style-guide) 1. [Rails](https://github.com/bbatsov/rails-style-guide)
1. [Testing](https://github.com/thoughtbot/guides/tree/master/style/testing) 1. [Testing](doc/development/testing.md)
1. [CoffeeScript](https://github.com/thoughtbot/guides/tree/master/style/coffeescript) 1. [CoffeeScript](https://github.com/thoughtbot/guides/tree/master/style/coffeescript)
1. [SCSS styleguide][scss-styleguide] 1. [SCSS styleguide][scss-styleguide]
1. [Shell commands](doc/development/shell_commands.md) created by GitLab 1. [Shell commands](doc/development/shell_commands.md) created by GitLab
......
...@@ -10,4 +10,5 @@ ...@@ -10,4 +10,5 @@
- [Shell commands](shell_commands.md) in the GitLab codebase - [Shell commands](shell_commands.md) in the GitLab codebase
- [Sidekiq debugging](sidekiq_debugging.md) - [Sidekiq debugging](sidekiq_debugging.md)
- [SQL guidelines](sql.md) for SQL guidelines - [SQL guidelines](sql.md) for SQL guidelines
- [Testing standards and style guidelines](testing.md)
- [UI guide](ui_guide.md) for building GitLab with existing css styles and elements - [UI guide](ui_guide.md) for building GitLab with existing css styles and elements
# Testing Standards and Style Guidelines
This guide outlines standards and best practices for automated testing of GitLab
CE and EE.
It is meant to be an _extension_ of the [thoughtbot testing
styleguide](https://github.com/thoughtbot/guides/tree/master/style/testing). If
this guide defines a rule that contradicts the thoughtbot guide, this guide
takes precedence. Some guidelines may be repeated verbatim to stress their
importance.
## Factories
GitLab uses [factory_girl] as a test fixture replacement.
- Factory definitions live in `spec/factories/`, named using the pluralization
of their corresponding model (`User` factories are defined in `users.rb`).
- There should be only one top-level factory definition per file.
- Make use of [Traits] to clean up definitions and usages.
- When defining a factory, don't define attributes that are not required for the
resulting record to pass validation.
- When instantiating from a factory, don't supply extraneous attributes that
aren't required by the test.
- Factories don't have to be limited to `ActiveRecord` objects.
[See example](https://gitlab.com/gitlab-org/gitlab-ce/commit/0b8cefd3b2385a21cfed779bd659978c0402766d).
[factory_girl]: https://github.com/thoughtbot/factory_girl
[Traits]: http://www.rubydoc.info/gems/factory_girl/file/GETTING_STARTED.md#Traits
## JavaScript
GitLab uses [Teaspoon] to run its [Jasmine] JavaScript specs. They can be run on
the command line via `bundle exec teaspoon`, or via a web browser at
`http://localhost:3000/teaspoon` when the Rails server is running.
- JavaScript tests live in `spec/javascripts/`, matching the folder structure of
`app/assets/javascripts/`: `app/assets/javascripts/behaviors/autosize.js.coffee` has a corresponding
`spec/javascripts/behaviors/autosize_spec.js.coffee` file.
- Haml fixtures required for JavaScript tests live in
`spec/javascripts/fixtures`. They should contain the bare minimum amount of
markup necessary for the test.
> **Warning:** Keep in mind that a Rails view may change and
invalidate your test, but everything will still pass because your fixture
doesn't reflect the latest view.
- Keep in mind that in a CI environment, these tests are run in a headless
browser and you will not have access to certain APIs, such as
[`Notification`](https://developer.mozilla.org/en-US/docs/Web/API/notification),
which will have to be stubbed.
[Teaspoon]: https://github.com/modeset/teaspoon
[Jasmine]: https://github.com/jasmine/jasmine
## RSpec
### General Guidelines
- Use a single, top-level `describe ClassName` block.
- Use `described_class` instead of repeating the class name being described.
- Use `.method` to describe class methods and `#method` to describe instance
methods.
- Use `context` to test branching logic.
- Don't `describe` symbols (see [Gotchas](gotchas.md#dont-describe-symbols)).
- Prefer `not_to` to `to_not`.
- Try to match the ordering of tests to the ordering within the class.
- Try to follow the [Four-Phase Test][four-phase-test] pattern, using newlines
to separate phases.
[four-phase-test]: https://robots.thoughtbot.com/four-phase-test
### `let` variables
GitLab's RSpec suite has made extensive use of `let` variables to reduce
duplication. However, this sometimes [comes at the cost of clarity][lets-not],
so we need to set some guidelines for their use going forward:
- `let` variables are preferable to instance variables. Local variables are
preferable to `let` variables.
- Use `let` to reduce duplication throughout an entire spec file.
- Don't use `let` to define variables used by a single test; define them as
local variables inside the test's `it` block.
- Don't define a `let` variable inside the top-level `describe` block that's
only used in a more deeply-nested `context` or `describe` block. Keep the
definition as close as possible to where it's used.
- Try to avoid overriding the definition of one `let` variable with another.
- Don't define a `let` variable that's only used by the definition of another.
Use a helper method instead.
[lets-not]: https://robots.thoughtbot.com/lets-not
### Test speed
GitLab has a massive test suite that, without parallelization, can take more
than an hour to run. It's important that we make an effort to write tests that
are accurate and effective _as well as_ fast.
Here are some things to keep in mind regarding test performance:
- `double` and `spy` are faster than `FactoryGirl.build(...)`
- `FactoryGirl.build(...)` and `.build_stubbed` are faster than `.create`.
- Don't `create` an object when `build`, `build_stubbed`, `attributes_for`,
`spy`, or `double` will do. Database persistence is slow!
- Use `create(:empty_project)` instead of `create(:project)` when you don't need
the underlying repository. Filesystem operations are slow!
- Don't mark a feature as requiring JavaScript (through `@javascript` in
Spinach or `js: true` in RSpec) unless it's _actually_ required for the test
to be valid. Headless browser testing is slow!
### Features / Integration
- Feature specs live in `spec/features/` and should be named
`ROLE_ACTION_spec.rb`, such as `user_changes_password_spec.rb`.
- Use only one `feature` block per feature spec file.
- Use scenario titles that describe the success and failure paths.
- Avoid scenario titles that add no information, such as "successfully."
- Avoid scenario titles that repeat the feature title.
## Spinach (feature) tests
GitLab [moved from Cucumber to Spinach](https://github.com/gitlabhq/gitlabhq/pull/1426)
for its feature/integration tests in September 2012.
As of March 2016, we are [trying to avoid adding new Spinach
tests](https://gitlab.com/gitlab-org/gitlab-ce/issues/14121) going forward,
opting for [RSpec feature](#features-integration) specs.
Adding new Spinach scenarios is acceptable _only if_ the new scenario requires
no more than one new `step` definition. If more than that is required, the
test should be re-implemented using RSpec instead.
---
[Return to Development documentation](README.md)
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