Tests: Add unit test for InternalScriptedMetric (#23330)

Relates to #22278

core/src/main/java/org/elasticsearch/search/aggregations/metrics/scripted/InternalScriptedMetric.java

@@ -35,6 +35,7 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 public class InternalScriptedMetric extends InternalAggregation implements ScriptedMetric {
     private final Script reduceScript;
@@ -126,4 +127,16 @@ public class InternalScriptedMetric extends InternalAggregation implements Scrip
         return builder.field("value", aggregation());
     }
 
+    @Override
+    protected boolean doEquals(Object obj) {
+        InternalScriptedMetric other = (InternalScriptedMetric) obj;
+        return Objects.equals(reduceScript, other.reduceScript) &&
+                Objects.equals(aggregation, other.aggregation);
+    }
+
+    @Override
+    protected int doHashCode() {
+        return Objects.hash(reduceScript, aggregation);
+    }
+
 }

core/src/test/java/org/elasticsearch/search/aggregations/InternalAggregationTestCase.java

@@ -21,6 +21,7 @@ package org.elasticsearch.search.aggregations;
 
 import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.search.SearchModule;
 import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
 import org.elasticsearch.test.AbstractWireSerializingTestCase;
@@ -36,9 +37,7 @@ public abstract class InternalAggregationTestCase<T extends InternalAggregation>
     private final NamedWriteableRegistry namedWriteableRegistry = new NamedWriteableRegistry(
             new SearchModule(Settings.EMPTY, false, emptyList()).getNamedWriteables());
 
-    protected abstract T createTestInstance(String name,
-            List<PipelineAggregator> pipelineAggregators,
-            Map<String, Object> metaData);
+    protected abstract T createTestInstance(String name, List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData);
 
     /** Return an instance on an unmapped field. */
     protected T createUnmappedInstance(String name,
@@ -57,21 +56,30 @@ public abstract class InternalAggregationTestCase<T extends InternalAggregation>
             inputs.add(t);
             toReduce.add(t);
         }
-        if (randomBoolean()) {
-            // we leave at least one in the list
-            List<InternalAggregation> internalAggregations = randomSubsetOf(randomIntBetween(1, toReduceSize), toReduce);
-            InternalAggregation.ReduceContext context = new InternalAggregation.ReduceContext(null, null, false);
+        ScriptService mockScriptService = mockScriptService();
+        if (randomBoolean() && toReduce.size() > 1) {
+            // we leave at least the first element in the list
+            List<InternalAggregation> internalAggregations = randomSubsetOf(randomIntBetween(1, toReduceSize - 1),
+                    toReduce.subList(1, toReduceSize));
+            InternalAggregation.ReduceContext context = new InternalAggregation.ReduceContext(null, mockScriptService, false);
             @SuppressWarnings("unchecked")
             T reduced = (T) inputs.get(0).reduce(internalAggregations, context);
             toReduce.removeAll(internalAggregations);
             toReduce.add(reduced);
         }
-        InternalAggregation.ReduceContext context = new InternalAggregation.ReduceContext(null, null, true);
+        InternalAggregation.ReduceContext context = new InternalAggregation.ReduceContext(null, mockScriptService, true);
         @SuppressWarnings("unchecked")
         T reduced = (T) inputs.get(0).reduce(toReduce, context);
         assertReduced(reduced, inputs);
     }
 
+    /**
+     * overwrite in tests that need it
+     */
+    protected ScriptService mockScriptService() {
+        return null;
+    }
+
     protected abstract void assertReduced(T reduced, List<T> inputs);
 
     @Override

core/src/test/java/org/elasticsearch/search/aggregations/metrics/scripted/InternalScriptedMetricTests.java

@@ -0,0 +1,110 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.search.aggregations.metrics.scripted;
+
+import org.elasticsearch.ElasticsearchException;
+import org.elasticsearch.common.io.stream.Writeable.Reader;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.env.Environment;
+import org.elasticsearch.script.MockScriptEngine;
+import org.elasticsearch.script.Script;
+import org.elasticsearch.script.ScriptContextRegistry;
+import org.elasticsearch.script.ScriptEngineRegistry;
+import org.elasticsearch.script.ScriptService;
+import org.elasticsearch.script.ScriptSettings;
+import org.elasticsearch.script.ScriptType;
+import org.elasticsearch.search.aggregations.InternalAggregationTestCase;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class InternalScriptedMetricTests extends InternalAggregationTestCase<InternalScriptedMetric> {
+
+    private static final String REDUCE_SCRIPT_NAME = "reduceScript";
+    // randomized only once so that any random test instance has the same value
+    private boolean hasReduceScript = randomBoolean();
+
+    @Override
+    protected InternalScriptedMetric createTestInstance(String name, List<PipelineAggregator> pipelineAggregators,
+            Map<String, Object> metaData) {
+        Map<String, Object> params = new HashMap<>();
+        if (randomBoolean()) {
+            params.put(randomAsciiOfLength(5), randomAsciiOfLength(5));
+        }
+        Script reduceScript = null;
+        if (hasReduceScript) {
+            reduceScript = new Script(ScriptType.INLINE, MockScriptEngine.NAME, REDUCE_SCRIPT_NAME, params);
+        }
+        return new InternalScriptedMetric(name, randomAsciiOfLength(5), reduceScript, pipelineAggregators, metaData);
+    }
+
+    /**
+     * Mock of the script service. The script that is run looks at the
+     * "_aggs" parameter visible when executing the script and simply returns the count.
+     * This should be equal to the number of input InternalScriptedMetrics that are reduced
+     * in total.
+     */
+    @Override
+    protected ScriptService mockScriptService() {
+        Settings settings = Settings.builder()
+                .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir())
+                // no file watching, so we don't need a ResourceWatcherService
+                .put(ScriptService.SCRIPT_AUTO_RELOAD_ENABLED_SETTING.getKey(), "false")
+                .build();
+        // mock script always retuns the size of the input aggs list as result
+        @SuppressWarnings("unchecked")
+        MockScriptEngine scriptEngine = new MockScriptEngine(MockScriptEngine.NAME,
+                Collections.singletonMap(REDUCE_SCRIPT_NAME, script -> {
+                    return ((List<Object>) script.get("_aggs")).size();
+                }));
+        ScriptEngineRegistry scriptEngineRegistry = new ScriptEngineRegistry(Collections.singletonList(scriptEngine));
+        ScriptContextRegistry scriptContextRegistry = new ScriptContextRegistry(Collections.emptyList());
+        ScriptSettings scriptSettings = new ScriptSettings(scriptEngineRegistry, scriptContextRegistry);
+        try {
+            return new ScriptService(settings, new Environment(settings), null, scriptEngineRegistry, scriptContextRegistry,
+                    scriptSettings);
+        } catch (IOException e) {
+            throw new ElasticsearchException(e);
+        }
+    }
+
+    @Override
+    protected void assertReduced(InternalScriptedMetric reduced, List<InternalScriptedMetric> inputs) {
+        InternalScriptedMetric firstAgg = inputs.get(0);
+        assertEquals(firstAgg.getName(), reduced.getName());
+        assertEquals(firstAgg.pipelineAggregators(), reduced.pipelineAggregators());
+        assertEquals(firstAgg.getMetaData(), reduced.getMetaData());
+        if (hasReduceScript) {
+            assertEquals(inputs.size(), reduced.aggregation());
+        } else {
+            assertEquals(inputs.size(), ((List<Object>) reduced.aggregation()).size());
+        }
+    }
+
+    @Override
+    protected Reader<InternalScriptedMetric> instanceReader() {
+        return InternalScriptedMetric::new;
+    }
+
+}