Implement toString() method for TensorFieldValue.

3 files changed, 19 insertions, 0 deletions

diff --git a/document/abi-spec.json b/document/abi-spec.json
index 7d7aad64bca..1a03221923f 100644
--- a/document/abi-spec.json
+++ b/document/abi-spec.json
@@ -3112,6 +3112,7 @@
       "public void <init>(com.yahoo.tensor.Tensor)",
       "public java.util.Optional getTensor()",
       "public com.yahoo.document.TensorDataType getDataType()",
+      "public java.lang.String toString()",
       "public void printXml(com.yahoo.document.serialization.XmlStream)",
       "public void clear()",
       "public void assign(java.lang.Object)",
diff --git a/document/src/main/java/com/yahoo/document/datatypes/TensorFieldValue.java b/document/src/main/java/com/yahoo/document/datatypes/TensorFieldValue.java
index 1808396986e..2c6a556c652 100644
--- a/document/src/main/java/com/yahoo/document/datatypes/TensorFieldValue.java
+++ b/document/src/main/java/com/yahoo/document/datatypes/TensorFieldValue.java
@@ -44,6 +44,15 @@ public class TensorFieldValue extends FieldValue {
     }
 
     @Override
+    public String toString() {
+        if (tensor.isPresent()) {
+            return tensor.get().toString();
+        } else {
+            return "null";
+        }
+    }
+
+    @Override
     public void printXml(XmlStream xml) {
         // TODO (geirst)
     }
diff --git a/document/src/test/java/com/yahoo/document/datatypes/TensorFieldValueTestCase.java b/document/src/test/java/com/yahoo/document/datatypes/TensorFieldValueTestCase.java
index b92d374004f..7293dcdb8eb 100644
--- a/document/src/test/java/com/yahoo/document/datatypes/TensorFieldValueTestCase.java
+++ b/document/src/test/java/com/yahoo/document/datatypes/TensorFieldValueTestCase.java
@@ -5,6 +5,7 @@ import com.yahoo.tensor.Tensor;
 import com.yahoo.tensor.TensorType;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
@@ -47,4 +48,12 @@ public class TensorFieldValueTestCase {
         assertTrue(field1.equals(field2));
         assertTrue(field1.equals(createFieldValue("{{x:0}:2.0}")));
     }
+
+    @Test
+    public void requireThatToStringWorks() {
+        TensorFieldValue field1 = createFieldValue("{{x:0}:2.0}");
+        assertEquals("tensor(x{}):{{x:0}:2.0}", field1.toString());
+        TensorFieldValue field2 = new TensorFieldValue(TensorType.fromSpec("tensor(x{})"));
+        assertEquals("null", field2.toString());
+    }
 }