From bb2d59e73ff7d3b076ef82ab2aa06d70e522847e Mon Sep 17 00:00:00 2001
From: "opensearch-trigger-bot[bot]"
 <98922864+opensearch-trigger-bot[bot]@users.noreply.github.com>
Date: Mon, 8 Jan 2024 12:01:19 -0800
Subject: [PATCH] Update Developer guide with steps to run BWC Test Suite
 (#531) (#532)

* Adding information on BWC tests in Developer guide

Signed-off-by: Varun Jain <varunudr@amazon.com>

---------

Signed-off-by: Varun Jain <varunudr@amazon.com>
(cherry picked from commit 91a1202714bbeb58412cb19c069f189c2d6ca3fe)

Co-authored-by: Varun Jain <varunudr@amazon.com>
---
 DEVELOPER_GUIDE.md | 25 +++++++++++++++++++++++++
 build.gradle       |  1 +
 2 files changed, 26 insertions(+)

diff --git a/DEVELOPER_GUIDE.md b/DEVELOPER_GUIDE.md
index 55678007e..3af2dd659 100644
--- a/DEVELOPER_GUIDE.md
+++ b/DEVELOPER_GUIDE.md
@@ -11,6 +11,8 @@
     - [Run Single-node Cluster Locally](#run-single-node-cluster-locally)
     - [Run Multi-node Cluster Locally](#run-multi-node-cluster-locally)
   - [Debugging](#debugging)
+  - [Backwards Compatibility Testing](#backwards-compatibility-testing)
+    - [Adding new tests](#adding-new-tests)
   - [Supported configurations](#supported-configurations)
   - [Submitting Changes](#submitting-changes)
 
@@ -184,6 +186,29 @@ Additionally, it is possible to attach one debugger to the cluster JVM and anoth
 ./gradlew :integTest -Dtest.debug=1 -Dcluster.debug=1
 ```
 
+## Backwards Compatibility Testing
+
+The purpose of Backwards Compatibility Testing and different types of BWC tests are explained [here](https://github.com/opensearch-project/opensearch-plugins/blob/main/TESTING.md#backwards-compatibility-testing). The BWC tests (i.e. Restart-Upgrade, Mixed-Cluster and Rolling-Upgrade scenarios) should be added with any new feature being added to Neural Search.
+The current design has mixed-cluster tests combined with rolling-upgrade tests in the same test class for [example](https://github.com/opensearch-project/neural-search/blob/main/qa/rolling-upgrade/src/test/java/org/opensearch/neuralsearch/bwc/SemanticSearchIT.java).
+
+Use these commands to run BWC tests for neural search:
+1. Rolling upgrade tests: `./gradlew :qa:rolling-upgrade:testRollingUpgrade`
+2. Full restart upgrade tests: `./gradlew :qa:restart-upgrade:testAgainstNewCluster`
+3. `./gradlew :qa:bwcTestSuite` is used to run all the above bwc tests together.
+
+bwc.version stands for the older version of OpenSearch against which one needs to check the compatibility with the current version.
+The details regarding all bwc versions of OpenSearch can be found [here](https://github.com/opensearch-project/OpenSearch/blob/main/libs/core/src/main/java/org/opensearch/Version.java).
+Use this command to run BWC tests for a given Backwards Compatibility Version:
+```
+./gradlew :qa:bwcTestSuite -Dbwc.version=2.9.0
+```
+Here, we are testing BWC Tests with BWC version of plugin as 2.9.0.
+The tests will not run on MAC OS due to issues coming from the OS.
+
+### Adding new tests
+
+Before adding any new tests to Backward Compatibility Tests, we should be aware that the tests in BWC are not independent. While creating an index, a test cannot use the same index name if it is already used in other tests.
+
 ### Supported configurations
 
 By default, neural-search plugin supports `lucene` k-NN engine for local runs. Below is the sample request for creating of new index using this engine:
diff --git a/build.gradle b/build.gradle
index 4a82e811e..ed1df95b8 100644
--- a/build.gradle
+++ b/build.gradle
@@ -194,6 +194,7 @@ project.tasks.delombok.dependsOn(extractKnnJar)
 
 compileJava {
     dependsOn extractKnnJar
+    dependsOn spotlessApply
     options.compilerArgs.addAll(["-processor", 'lombok.launch.AnnotationProcessorHider$AnnotationProcessor'])
 }
 compileTestJava {