Add latest changes from gitlab-org/gitlab@master

2 files changed, 27 insertions, 1 deletions

diff --git a/doc/development/fe_guide/development_process.md b/doc/development/fe_guide/development_process.md
index ff36b8b5c6a..2b64534e7c9 100644
--- a/doc/development/fe_guide/development_process.md
+++ b/doc/development/fe_guide/development_process.md
@@ -4,7 +4,7 @@ You can find more about the organization of the frontend team in the [handbook](
 
 ## Development Checklist
 
-The idea is to remind us about specific topics during the time we build a new feature or start something. This is a common practice in other industries (like pilots) that also use standardised checklists to reduce problems early on.
+The idea is to remind us about specific topics during the time we build a new feature or start something. This is a common practice in other industries (like pilots) that also use standardized checklists to reduce problems early on.
 
 Copy the content over to your issue or merge request and if something doesn't apply simply remove it from your current list.
 
diff --git a/doc/development/testing_guide/best_practices.md b/doc/development/testing_guide/best_practices.md
index 8a1ee74a7fc..d9e7f0e6535 100644
--- a/doc/development/testing_guide/best_practices.md
+++ b/doc/development/testing_guide/best_practices.md
@@ -94,6 +94,32 @@ let(:project) { create(:project) }
 let_it_be(:project) { create(:project) }
 ```
 
+A common cause of a large number of created factories is [factory cascades](https://github.com/test-prof/test-prof/blob/master/docs/profilers/factory_prof.md#factory-flamegraph), which result when factories create and recreate associations.
+They can be identified by a noticeable difference between `total time` and `top-level time` numbers:
+
+```shell
+   total   top-level     total time      time per call      top-level time               name
+
+     208           0        9.5812s            0.0461s             0.0000s          namespace
+     208          76       37.4214s            0.1799s            13.8749s            project
+```
+
+In order to reuse a single factory for all implicit parent associations,
+[`FactoryDefault`](https://github.com/test-prof/test-prof/blob/master/docs/recipes/factory_default.md)
+can be used:
+
+```ruby
+  let_it_be(:namespace) { create_default(:namespace) }
+  let_it_be(:project) { create_default(:project) }
+```
+
+In this case, the `total time` and `top-level time` numbers match more closely:
+
+```shell
+      31          30        4.6378s            0.1496s             4.5366s            project
+       8           8        0.0477s            0.0477s             0.0477s          namespace
+```
+
 ### General guidelines
 
 - Use a single, top-level `RSpec.describe ClassName` block.