1 files changed, 10 insertions, 0 deletions
diff --git a/vespajlib/src/test/java/com/yahoo/tensor/IndexedTensorTestCase.java b/vespajlib/src/test/java/com/yahoo/tensor/IndexedTensorTestCase.java
index 3a6a7f2f65d..09b6e79a101 100644
--- a/vespajlib/src/test/java/com/yahoo/tensor/IndexedTensorTestCase.java
+++ b/vespajlib/src/test/java/com/yahoo/tensor/IndexedTensorTestCase.java
@@ -3,6 +3,7 @@ package com.yahoo.tensor;
 import junit.framework.TestCase;
 import org.junit.Test;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
@@ -63,6 +64,15 @@ public class IndexedTensorTestCase {
         assertBuildingVWXYZ(type);
     }
     
+    @Test
+    public void testUnderspecifiedBuilding() {
+        TensorType type = new TensorType.Builder().indexed("x").build();
+        Tensor.Builder builder = Tensor.Builder.of(type);
+        builder.cell(47.0, 98);
+        Tensor tensor = builder.build();
+        assertEquals(47.0, tensor.sum(Collections.singletonList("x")).asDouble(), 0.000001);
+    }
+    
     private void assertBuildingVWXYZ(TensorType type) {
         IndexedTensor.Builder builder = IndexedTensor.Builder.of(type);
         // Build in scrambled order