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Diffstat (limited to 'doc/development/testing_guide/best_practices.md')
| -rw-r--r-- | doc/development/testing_guide/best_practices.md | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/doc/development/testing_guide/best_practices.md b/doc/development/testing_guide/best_practices.md index 6ef9be381b4..2c1d70a005e 100644 --- a/doc/development/testing_guide/best_practices.md +++ b/doc/development/testing_guide/best_practices.md @@ -81,7 +81,7 @@ browser is much slower than parsing the HTML response from the app. A common cause of slow tests is excessive creation of objects, and thus computation and DB time. Factories are essential to development, but they can -make inserting data into the DB so easy that we may be able to optimize. +make inserting data into the DB so easy that we may be able to optimize. The two basic techniques to bear in mind here are: @@ -151,11 +151,14 @@ In order to reuse a single object for all calls to a named factory in implicit p can be used: ```ruby +RSpec.describe API::Search, factory_default: :keep do let_it_be(:namespace) { create_default(:namespace) } ``` Then every project we create will use this `namespace`, without us having to pass -it as `namespace: namespace`. +it as `namespace: namespace`. In order to make it work along with `let_it_be`, `factory_default: :keep` +must be explicitly specified. That will keep the default factory for every example in a suite instead of +recreating it for each example. Maybe we don't need to create 208 different projects - we can create one and reuse it. In addition, we can see that only about 1/3 of the @@ -237,7 +240,7 @@ end it 'schedules a background job' do expect(BackgroundJob).to receive(:perform_async) - + subject.execute end ``` @@ -249,7 +252,7 @@ combining the examples: ```ruby it 'performs the expected side-effects' do expect(BackgroundJob).to receive(:perform_async) - + expect { subject.execute } .to change(Event, :count).by(1) .and change { arg_0.frobulance }.to('wibble') @@ -481,26 +484,30 @@ This will result in only one `Project`, `User`, and `ProjectMember` created for is handled automatically using a transaction rollback. Note that if you modify an object defined inside a `let_it_be` block, -then you will need to reload the object as needed, or specify the `reload` -option to reload for every example. +then you must do one of the following: + +- Reload the object as needed. +- Use the `let_it_be_with_reload` alias. +- Specify the `reload` option to reload for every example. ```ruby +let_it_be_with_reload(:project) { create(:project) } let_it_be(:project, reload: true) { create(:project) } ``` -You can also specify the `refind` option as well to completely load a -new object. +You can also use the `let_it_be_with_refind` alias, or specify the `refind` +option as well to completely load a new object. ```ruby +let_it_be_with_refind(:project) { create(:project) } let_it_be(:project, refind: true) { create(:project) } ``` ### Time-sensitive tests -[Timecop](https://github.com/travisjeffery/timecop) is available in our -Ruby-based tests for verifying things that are time-sensitive. Any test that -exercises or verifies something time-sensitive should make use of Timecop to -prevent transient test failures. +[`ActiveSupport::Testing::TimeHelpers`](https://api.rubyonrails.org/v6.0.3.1/classes/ActiveSupport/Testing/TimeHelpers.html) +can be used to verify things that are time-sensitive. Any test that exercises or verifies something time-sensitive +should make use of these helpers to prevent transient test failures. Example: @@ -508,7 +515,7 @@ Example: it 'is overdue' do issue = build(:issue, due_date: Date.tomorrow) - Timecop.freeze(3.days.from_now) do + travel_to(3.days.from_now) do expect(issue).to be_overdue end end @@ -888,6 +895,10 @@ GitLab uses [factory_bot](https://github.com/thoughtbot/factory_bot) as a test f resulting record to pass validation. - When instantiating from a factory, don't supply attributes that aren't required by the test. +- Prefer [implicit](https://github.com/thoughtbot/factory_bot/blob/master/GETTING_STARTED.md#implicit-definition) + or [explicit](https://github.com/thoughtbot/factory_bot/blob/master/GETTING_STARTED.md#explicit-definition) + association definitions instead of using `create` / `build` for association setup. + See [issue #262624](https://gitlab.com/gitlab-org/gitlab/-/issues/262624) for further context. - Factories don't have to be limited to `ActiveRecord` objects. [See example](https://gitlab.com/gitlab-org/gitlab-foss/commit/0b8cefd3b2385a21cfed779bd659978c0402766d). |