added util method (#40)

Co-authored-by: Sarthak Singhal <[email protected]>

data-model/src/main/java/org/hypertrace/core/datamodel/shared/TraceAttributeUtils.java

@@ -1,5 +1,6 @@
 package org.hypertrace.core.datamodel.shared;
 
+import java.util.List;
 import java.util.Optional;
 import org.hypertrace.core.datamodel.AttributeValue;
 import org.hypertrace.core.datamodel.Event;
@@ -31,6 +32,23 @@ public static String getStringAttribute(StructuredTrace trace, String attribute)
     return value.getValue();
   }
 
+  public static List<String> getListAttribute(StructuredTrace trace, String attribute) {
+    if (trace.getAttributes() == null) {
+      return null;
+    }
+
+    if (trace.getAttributes().getAttributeMap() == null) {
+      return null;
+    }
+
+    AttributeValue value = trace.getAttributes().getAttributeMap().get(attribute);
+    if (value == null) {
+      return null;
+    }
+
+    return value.getValueList();
+  }
+
   public static Optional<String> getAttributeValueIncludeSearchInSpans(
       StructuredTrace trace, String key) {
     if (trace == null) {

data-model/src/test/java/org/hypertrace/core/datamodel/shared/TraceAttributeUtilsTest.java

@@ -0,0 +1,38 @@
+package org.hypertrace.core.datamodel.shared;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import org.hypertrace.core.datamodel.AttributeValue;
+import org.hypertrace.core.datamodel.Attributes;
+import org.hypertrace.core.datamodel.StructuredTrace;
+import org.junit.jupiter.api.Test;
+
+public class TraceAttributeUtilsTest {
+
+  @Test
+  public void getListAttributeTest() {
+    StructuredTrace mockTrace = mock(StructuredTrace.class);
+    assertNull(TraceAttributeUtils.getListAttribute(mockTrace, "someattribute"));
+
+    when(mockTrace.getAttributes()).thenReturn(Attributes.newBuilder().build());
+    assertNull(TraceAttributeUtils.getListAttribute(mockTrace, "someattribute"));
+
+    Map<String, AttributeValue> attributeMap = new HashMap<>();
+    when(mockTrace.getAttributes())
+        .thenReturn(Attributes.newBuilder().setAttributeMap(attributeMap).build());
+    assertNull(TraceAttributeUtils.getListAttribute(mockTrace, "someattribute"));
+
+    attributeMap.put(
+        "someattribute",
+        AttributeValue.newBuilder().setValueList(List.of("somevalue1", "somevalue2")).build());
+    assertEquals(
+        List.of("somevalue1", "somevalue2"),
+        TraceAttributeUtils.getListAttribute(mockTrace, "someattribute"));
+  }
+}