From 77ffa9b4c60dcd7f31d38ee73de38257c24c6e51 Mon Sep 17 00:00:00 2001
From: John Mazanec <jmazane@amazon.com>
Date: Tue, 5 Apr 2022 10:26:48 -0700
Subject: [PATCH] Parse null parameters value in method parsers

Allow user to input null value for parameters field for KNNMethodContext
and MethodComponentContext.

Signed-off-by: John Mazanec <jmazane@amazon.com>
---
 .../org/opensearch/knn/index/KNNMethodContext.java     |  6 +++++-
 .../opensearch/knn/index/MethodComponentContext.java   | 10 +++++++---
 .../opensearch/knn/index/KNNMethodContextTests.java    |  8 ++++----
 .../knn/index/MethodComponentContextTests.java         |  8 ++++----
 4 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/main/java/org/opensearch/knn/index/KNNMethodContext.java b/src/main/java/org/opensearch/knn/index/KNNMethodContext.java
index 4667640bf..0f4281e21 100644
--- a/src/main/java/org/opensearch/knn/index/KNNMethodContext.java
+++ b/src/main/java/org/opensearch/knn/index/KNNMethodContext.java
@@ -42,7 +42,7 @@
  */
 public class KNNMethodContext implements ToXContentFragment, Writeable {
 
-    private static Logger logger = LogManager.getLogger(KNNMethodContext.class);
+    private static final Logger logger = LogManager.getLogger(KNNMethodContext.class);
 
     private static KNNMethodContext defaultInstance = null;
 
@@ -194,6 +194,10 @@ public static KNNMethodContext parse(Object in) {
 
                 name = (String) value;
             } else if (PARAMETERS.equals(key)) {
+                if (value == null) {
+                    continue;
+                }
+
                 if (!(value instanceof Map)) {
                     throw new MapperParsingException("Unable to parse parameters for main method component");
                 }
diff --git a/src/main/java/org/opensearch/knn/index/MethodComponentContext.java b/src/main/java/org/opensearch/knn/index/MethodComponentContext.java
index a8c93fe4c..73ffcae6e 100644
--- a/src/main/java/org/opensearch/knn/index/MethodComponentContext.java
+++ b/src/main/java/org/opensearch/knn/index/MethodComponentContext.java
@@ -37,10 +37,10 @@
  */
 public class MethodComponentContext implements ToXContentFragment, Writeable {
 
-    private static Logger logger = LogManager.getLogger(MethodComponentContext.class);
+    private static final Logger logger = LogManager.getLogger(MethodComponentContext.class);
 
-    private String name;
-    private Map<String, Object> parameters;
+    private final String name;
+    private final Map<String, Object> parameters;
 
     /**
      * Constructor
@@ -93,6 +93,10 @@ public static MethodComponentContext parse(Object in) {
                 }
                 name = (String) value;
             } else if (PARAMETERS.equals(key)) {
+                if (value == null) {
+                    continue;
+                }
+
                 if (!(value instanceof Map)) {
                     throw new MapperParsingException("Unable to parse parameters for  method component");
                 }
diff --git a/src/test/java/org/opensearch/knn/index/KNNMethodContextTests.java b/src/test/java/org/opensearch/knn/index/KNNMethodContextTests.java
index 30503d7ed..176029ad6 100644
--- a/src/test/java/org/opensearch/knn/index/KNNMethodContextTests.java
+++ b/src/test/java/org/opensearch/knn/index/KNNMethodContextTests.java
@@ -245,10 +245,10 @@ public void testParse_invalid() throws IOException {
     public void testParse_nullParameters() throws IOException {
         String methodName = "test-method";
         XContentBuilder xContentBuilder = XContentFactory.jsonBuilder()
-                .startObject()
-                .field(NAME, methodName)
-                .field(PARAMETERS, (String) null)
-                .endObject();
+            .startObject()
+            .field(NAME, methodName)
+            .field(PARAMETERS, (String) null)
+            .endObject();
         Map<String, Object> in = xContentBuilderToMap(xContentBuilder);
         KNNMethodContext knnMethodContext = KNNMethodContext.parse(in);
         assertTrue(knnMethodContext.getMethodComponent().getParameters().isEmpty());
diff --git a/src/test/java/org/opensearch/knn/index/MethodComponentContextTests.java b/src/test/java/org/opensearch/knn/index/MethodComponentContextTests.java
index 14b8bf4d0..826bf3c83 100644
--- a/src/test/java/org/opensearch/knn/index/MethodComponentContextTests.java
+++ b/src/test/java/org/opensearch/knn/index/MethodComponentContextTests.java
@@ -113,10 +113,10 @@ public void testGetParameters() throws IOException {
     public void testParse_nullParameters() throws IOException {
         String name = "test-name";
         XContentBuilder xContentBuilder = XContentFactory.jsonBuilder()
-                .startObject()
-                .field(NAME, name)
-                .field(PARAMETERS, (String) null)
-                .endObject();
+            .startObject()
+            .field(NAME, name)
+            .field(PARAMETERS, (String) null)
+            .endObject();
         Map<String, Object> in = xContentBuilderToMap(xContentBuilder);
         MethodComponentContext methodComponentContext = MethodComponentContext.parse(in);
         assertTrue(methodComponentContext.getParameters().isEmpty());