Make KNN metric parsin case insensitive

Author: jjaderberg

algo/src/main/java/org/neo4j/gds/similarity/knn/KnnNodePropertySpecParser.java

@@ -28,6 +28,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.stream.Collectors;
 
@@ -113,7 +114,7 @@ private static List<KnnNodePropertySpec> fromMap(Map<String, String> userInput)
             SimilarityMetric similarityMetric;
             if (value != null) {
                 try {
-                    similarityMetric = SimilarityMetric.valueOf(value);
+                    similarityMetric = SimilarityMetric.valueOf(value.toUpperCase(Locale.ENGLISH));
                     knnNodeProperties.add(new KnnNodePropertySpec(key, similarityMetric));
                 } catch (IllegalArgumentException ex) {
                     throw new IllegalArgumentException(

algo/src/test/java/org/neo4j/gds/similarity/knn/KnnNodePropertySpecParserTest.java

@@ -20,9 +20,12 @@
 package org.neo4j.gds.similarity.knn;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.neo4j.gds.similarity.knn.metrics.SimilarityMetric;
 
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -103,6 +106,16 @@ void shouldParseMap() {
             );
     }
 
+    @ParameterizedTest
+    @ValueSource(strings = {"cosine", "euCLIDean", "jACcaRd", "OVERLAP", "Pearson"})
+    void shouldAcceptMetricsRegardlessOfCase(String metric) {
+        var input = "property";
+        assertThat(KnnNodePropertySpecParser.parse(Map.of(input, metric)))
+            .singleElement()
+            .extracting(spec -> spec.metric().name())
+            .isEqualTo(metric.toUpperCase(Locale.ENGLISH));
+    }
+
     @Test
     void shouldRefuseToParseEmptyList() {
         var input = List.of();