1 files changed, 35 insertions, 0 deletions
diff --git a/vespajlib/src/test/java/com/yahoo/tensor/functions/ReduceTestCase.java b/vespajlib/src/test/java/com/yahoo/tensor/functions/ReduceTestCase.java
new file mode 100644
index 00000000000..21fed1745b9
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+++ b/vespajlib/src/test/java/com/yahoo/tensor/functions/ReduceTestCase.java
@@ -0,0 +1,35 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.tensor.functions;
+
+import com.yahoo.tensor.Tensor;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author bratseth
+ */
+public class ReduceTestCase {
+
+    private static final double delta = 0.00000001;
+
+    @Test
+    public void testReduce() {
+        assertNan(Tensor.from("tensor(x{})", "{}").median());
+        assertEquals(1.0, Tensor.from("tensor(x[1])", "[1]").median().asDouble(), delta);
+        assertEquals(1.5, Tensor.from("tensor(x[2])", "[1, 2]").median().asDouble(), delta);
+        assertEquals(3.0, Tensor.from("tensor(x[7])", "[3, 1, 1, 1, 4, 4, 4]").median().asDouble(), delta);
+        assertEquals(2.0, Tensor.from("tensor(x[6])", "[3, 1, 1, 1, 4, 4]").median().asDouble(), delta);
+        assertEquals(2.0, Tensor.from("tensor(x{})", "{{x: foo}: 3, {x:bar}: 1}").median().asDouble(), delta);
+
+        assertNan(Tensor.Builder.of("tensor(x[3])").cell(Double.NaN, 0).cell(1, 1).cell(2, 2).build().median());
+        assertNan(Tensor.Builder.of("tensor(x[3])").cell(Double.NaN, 2).cell(1, 1).cell(2, 0).build().median());
+        assertNan(Tensor.Builder.of("tensor(x[1])").cell(Double.NaN, 0).build().median());
+    }
+
+    private void assertNan(Tensor tensor) {
+        assertTrue(tensor + " is NaN", Double.isNaN(tensor.asDouble()));
+    }
+
+}