1 files changed, 51 insertions, 0 deletions
diff --git a/config-model/src/test/java/com/yahoo/schema/document/HnswIndexParamsTestCase.java b/config-model/src/test/java/com/yahoo/schema/document/HnswIndexParamsTestCase.java
new file mode 100644
index 00000000000..8ef51369ecb
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+++ b/config-model/src/test/java/com/yahoo/schema/document/HnswIndexParamsTestCase.java
@@ -0,0 +1,51 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+package com.yahoo.schema.document;
+
+import java.util.Optional;
+import org.junit.Test;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class HnswIndexParamsTestCase {
+
+    @Test
+    public void override_from() throws Exception {
+        var empty = new HnswIndexParams();
+        var builder = new HnswIndexParams.Builder();
+        builder.setMaxLinksPerNode(7);
+        builder.setMultiThreadedIndexing(false);
+        var one = builder.build();
+        builder.setNeighborsToExploreAtInsert(42);
+        var three = builder.build();
+        builder.setMaxLinksPerNode(17);
+        builder.setNeighborsToExploreAtInsert(500);
+        builder.setMultiThreadedIndexing(true);
+        var four = builder.build();
+
+        assertThat(empty.maxLinksPerNode(), is(16));
+        assertThat(empty.neighborsToExploreAtInsert(), is(200));
+        assertThat(empty.multiThreadedIndexing(), is(true));
+
+        assertThat(one.maxLinksPerNode(), is(7));
+        assertThat(one.multiThreadedIndexing(), is(false));
+        assertThat(three.neighborsToExploreAtInsert(), is(42));
+
+        assertThat(four.maxLinksPerNode(), is(17));
+        assertThat(four.neighborsToExploreAtInsert(), is(500));
+        assertThat(four.multiThreadedIndexing(), is(true));
+
+        var five = four.overrideFrom(Optional.of(empty));
+        assertThat(five.maxLinksPerNode(), is(17));
+        assertThat(five.neighborsToExploreAtInsert(), is(500));
+        assertThat(five.multiThreadedIndexing(), is(true));
+
+        var six = four.overrideFrom(Optional.of(one));
+        assertThat(six.maxLinksPerNode(), is(7));
+        assertThat(six.neighborsToExploreAtInsert(), is(500));
+        // This is explicitly set to false in 'one'
+        assertThat(six.multiThreadedIndexing(), is(false));
+    }
+
+}