random tests

Author: jan-elastic

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/scalar/approximate/Random.java

@@ -16,6 +16,7 @@
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
+import org.elasticsearch.xpack.esql.core.type.DataType;
 import org.elasticsearch.xpack.esql.expression.function.EsqlFunctionRegistry;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
 import org.elasticsearch.xpack.esql.expression.function.FunctionType;
@@ -25,6 +26,9 @@
 import java.io.IOException;
 import java.util.List;
 
+import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.ParamOrdinal.DEFAULT;
+import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isType;
+
 /**
  * This function is used internally by {@link Approximate}, and is not exposed
  * to users via the {@link EsqlFunctionRegistry}.
@@ -63,6 +67,11 @@ public ExpressionEvaluator.Factory toEvaluator(ToEvaluator toEvaluator) {
         return new RandomEvaluator.Factory(source(), toEvaluator.apply(field));
     }
 
+    @Override
+    protected Expression.TypeResolution resolveType() {
+        return isType(field, t -> t == DataType.INTEGER, sourceText(), DEFAULT, "int");
+    }
+
     @Override
     public final Expression replaceChildren(List<Expression> newChildren) {
         return new Random(source(), newChildren.get(0));
@@ -75,6 +84,6 @@ protected NodeInfo<? extends Expression> info() {
 
     @Override
     public boolean foldable() {
-        return false;
+        return field.dataType() == DataType.NULL;
     }
 }

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/scalar/approximate/ConfidenceIntervalTests.java

@@ -16,7 +16,6 @@
 import org.elasticsearch.xpack.esql.expression.function.AbstractScalarFunctionTestCase;
 import org.elasticsearch.xpack.esql.expression.function.TestCaseSupplier;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Supplier;
 import java.util.stream.IntStream;
@@ -33,13 +32,14 @@ public class ConfidenceIntervalTests extends AbstractScalarFunctionTestCase {
 
     @ParametersFactory
     public static Iterable<Object[]> parameters() {
-        List<TestCaseSupplier> suppliers = new ArrayList<>();
-        suppliers.add(randomBuckets());
-        suppliers.add(allBucketsFilled());
-        suppliers.add(nanBuckets_ignoreNan());
-        suppliers.add(nanBuckets_zeroNan());
-        suppliers.add(inconsistentData());
-        suppliers.add(manyNans());
+        List<TestCaseSupplier> suppliers = List.of(
+            randomBuckets(),
+            allBucketsFilled(),
+            nanBuckets_ignoreNan(),
+            nanBuckets_zeroNan(),
+            inconsistentData(),
+            manyNans()
+        );
         return parameterSuppliersFromTypedDataWithDefaultChecks(false, suppliers);
     }
 

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/scalar/approximate/RandomErrorTests.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.esql.expression.function.scalar.approximate;
+
+import org.elasticsearch.xpack.esql.core.expression.Expression;
+import org.elasticsearch.xpack.esql.core.tree.Source;
+import org.elasticsearch.xpack.esql.core.type.DataType;
+import org.elasticsearch.xpack.esql.expression.function.ErrorsForCasesWithoutExamplesTestCase;
+import org.elasticsearch.xpack.esql.expression.function.TestCaseSupplier;
+import org.hamcrest.Matcher;
+
+import java.util.List;
+import java.util.Set;
+
+import static org.hamcrest.Matchers.equalTo;
+
+public class RandomErrorTests extends ErrorsForCasesWithoutExamplesTestCase {
+    @Override
+    protected List<TestCaseSupplier> cases() {
+        return paramsToSuppliers(RandomTests.parameters());
+    }
+
+    @Override
+    protected Expression build(Source source, List<Expression> args) {
+        return new Random(source, args.get(0));
+    }
+
+    @Override
+    protected Matcher<String> expectedTypeErrorMatcher(List<Set<DataType>> validPerPosition, List<DataType> signature) {
+        return equalTo(typeErrorMessage(false, validPerPosition, signature, (v, i) -> "int"));
+    }
+}

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/scalar/approximate/RandomSerializationTests.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.esql.expression.function.scalar.approximate;
+
+import org.elasticsearch.xpack.esql.expression.AbstractExpressionSerializationTests;
+
+import java.io.IOException;
+
+public class RandomSerializationTests extends AbstractExpressionSerializationTests<Random> {
+
+    @Override
+    protected Random createTestInstance() {
+        return new Random(randomSource(), randomChild());
+    }
+
+    @Override
+    protected Random mutateInstance(Random instance) throws IOException {
+        return new Random(instance.source(), randomValueOtherThan(instance.field(), AbstractExpressionSerializationTests::randomChild));
+    }
+}

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/scalar/approximate/RandomTests.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.esql.expression.function.scalar.approximate;
+
+import com.carrotsearch.randomizedtesting.annotations.Name;
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
+import org.elasticsearch.xpack.esql.core.expression.Expression;
+import org.elasticsearch.xpack.esql.core.tree.Source;
+import org.elasticsearch.xpack.esql.core.type.DataType;
+import org.elasticsearch.xpack.esql.expression.function.AbstractScalarFunctionTestCase;
+import org.elasticsearch.xpack.esql.expression.function.TestCaseSupplier;
+
+import java.util.List;
+import java.util.function.Supplier;
+
+import static org.hamcrest.Matchers.allOf;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.lessThan;
+
+public class RandomTests extends AbstractScalarFunctionTestCase {
+
+    @ParametersFactory
+    public static Iterable<Object[]> parameters() {
+        List<TestCaseSupplier> suppliers = List.of(new TestCaseSupplier("Basic Case", List.of(DataType.INTEGER), () -> {
+            int bound = randomIntBetween(1, 100);
+            return new TestCaseSupplier.TestCase(
+                List.of(new TestCaseSupplier.TypedData(bound, DataType.INTEGER, "bound")),
+                "RandomEvaluator[bound=Attribute[channel=0]]",
+                DataType.INTEGER,
+                allOf(instanceOf(Integer.class), greaterThanOrEqualTo(0), lessThan(bound))
+            );
+        }));
+        return parameterSuppliersFromTypedDataWithDefaultChecks(false, suppliers);
+    }
+
+    public RandomTests(@Name("TestCase") Supplier<TestCaseSupplier.TestCase> testCaseSupplier) {
+        this.testCase = testCaseSupplier.get();
+    }
+
+    @Override
+    protected Expression build(Source source, List<Expression> args) {
+        return new Random(source, args.get(0));
+    }
+
+    @Override
+    public void testFold() {
+        // Random cannot be folded as it is non-deterministic.
+    }
+}