e2e-tests: Refactor documentation about functional
Add functional e2e testing information to the documentation, alongside
the previous load-only text. Clarify the Gerrit test scopes along the
way, thus how to cover them in this newly emerging e2e test framework
context. Refactor the related documentation paragraphs to support this.
Change-Id: Ic20c5c8f96d0aaa3fb568c282b1d5ef77167627f
diff --git a/Documentation/dev-e2e-tests.txt b/Documentation/dev-e2e-tests.txt
index 3212387..672981f 100644
--- a/Documentation/dev-e2e-tests.txt
+++ b/Documentation/dev-e2e-tests.txt
@@ -1,28 +1,36 @@
-= Gerrit Code Review - End to end load tests
+= Gerrit Code Review - End to end tests
-This document provides a description of a Gerrit load test scenario implemented using the
-link:https://gatling.io/[Gatling] framework.
+This document provides descriptions of Gerrit end-to-end (`e2e`) test scenarios implemented using
+the link:https://gatling.io/[Gatling] framework.
Similar scenarios have been successfully used to compare performance of different Gerrit versions
-or study the Gerrit response under different load profiles.
+or study the Gerrit response under different load profiles. Although mostly for load, scenarios can
+either be for link:https://gatling.io/load-testing-continuous-integration/[load or functional]
+(e2e) testing purposes. Functional scenarios may then reuse this framework and Gatling's usability
+features such as its protocols (more below) and
+link:https://en.wikipedia.org/wiki/Domain-specific_language[DSL].
+
+That cross test-scope reusability applies to both Gerrit core scenarios and non-core ones, such as
+for Gerrit plugins or other potential extensions. End-to-end testing may then include scopes like
+feature integration, deployment, smoke (and load) testing. These load and functional test scopes
+should remain orthogonal to the unit and component (aka Gerrit `IT`-suffixed or `acceptance`) ones.
+The term `acceptance` though may still be coined by organizations to target e2e functional testing.
== What is Gatling?
-Gatling is a load testing tool which provides out of the box support for the HTTP protocol.
+Gatling is mostly a load testing tool which provides out of the box support for the HTTP protocol.
Documentation on how to write an HTTP load test can be found
-link:https://gatling.io/docs/current/http/http_protocol/[here].
-
-However, in the scenario we are proposing, we are leveraging the
-link:https://github.com/GerritForge/gatling-git[Gatling Git extension] to run tests at Git
-protocol level.
+link:https://gatling.io/docs/current/http/http_protocol/[here]. However, in the scenarios that were
+initially proposed, the link:https://github.com/GerritForge/gatling-git[Gatling Git extension] was
+leveraged to run tests at the Git protocol level.
Gatling is written in Scala, but the abstraction provided by the Gatling DSL makes the scenarios
implementation easy even without any Scala knowledge. The
link:https://gitenterprise.me/2019/12/20/stress-your-gerrit-with-gatling/[Stress your Gerrit with Gatling]
blog post has more introductory information.
-Examples of scenarios can be found in the `e2e-tests` directory. The files in that directory
-should be formatted using the mainstream
+Examples of scenarios can be found in the `e2e-tests` directory. The files in that directory should
+be formatted using the mainstream
link:https://plugins.jetbrains.com/plugin/1347-scala[Scala plugin for IntelliJ]. The latter is not
mandatory but preferred for `sbt` and Scala IDE purposes in this project.
@@ -86,7 +94,7 @@
The `CloneUsingBothProtocols` scenario is fed with the data coming from the
`src/test/resources/data/com/google/gerrit/scenarios/CloneUsingBothProtocols.json` file. Such a
-file contains the commands and repository used during the load test. That file currently looks like
+file contains the commands and repository used during the e2e test. That file currently looks like
below. This scenario serves as a simple example with no actual load in it. It can be used to test
or validate the local setup. More complex scenarios can be further developed, under the
`com.google.gerrit.scenarios` package.
