ESQL: Small fixes for COPY_SIGN

docs/changelog/132459.yaml

@@ -0,0 +1,5 @@
+pr: 132459
+summary: Small fixes for COPY_SIGN
+area: ES|QL
+type: bug
+issues: []

docs/reference/query-languages/esql/_snippets/lists/math-functions.md

@@ -5,6 +5,7 @@
 * [`ATAN2`](../../functions-operators/math-functions.md#esql-atan2)
 * [`CBRT`](../../functions-operators/math-functions.md#esql-cbrt)
 * [`CEIL`](../../functions-operators/math-functions.md#esql-ceil)
+* [`COPY_SIGN`](../../functions-operators/math-functions.md#esql-copy_sign)
 * [`COS`](../../functions-operators/math-functions.md#esql-cos)
 * [`COSH`](../../functions-operators/math-functions.md#esql-cosh)
 * [`E`](../../functions-operators/math-functions.md#esql-e)

docs/reference/query-languages/esql/functions-operators/math-functions.md

@@ -33,6 +33,9 @@ mapped_pages:
 :::{include} ../_snippets/functions/layout/ceil.md
 :::
 
+:::{include} ../_snippets/functions/layout/copy_sign.md
+:::
+
 :::{include} ../_snippets/functions/layout/cos.md
 :::
 

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

@@ -15,6 +15,7 @@
 import org.elasticsearch.xpack.esql.EsqlIllegalArgumentException;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.expression.Expressions;
+import org.elasticsearch.xpack.esql.core.expression.TypeResolutions;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
@@ -60,21 +61,20 @@ EvalOperator.ExpressionEvaluator.Factory create(
 
     private DataType dataType;
 
-    @FunctionInfo(
-        description = "Returns a value with the magnitude of the first argument and the sign of the second argument. "
-            + "This function is similar to Java's Math.copySign(double magnitude, double sign).",
-        returnType = { "double", "float" }
-    )
+    @FunctionInfo(description = """
+        Returns a value with the magnitude of the first argument and the sign of the second argument.
+        This function is similar to Java's Math.copySign(double magnitude, double sign) which is
+        similar to `copysign` from [IEEE 754](https://en.wikipedia.org/wiki/IEEE_754).""", returnType = { "double", "integer", "long" })
     public CopySign(
         Source source,
         @Param(
             name = "magnitude",
-            type = { "double", "float", "integer", "long" },
+            type = { "double", "integer", "long" },
             description = "The expression providing the magnitude of the result. Must be a numeric type."
         ) Expression magnitude,
         @Param(
             name = "sign",
-            type = { "double", "float", "integer", "long" },
+            type = { "double", "integer", "long" },
             description = "The expression providing the sign of the result. Must be a numeric type."
         ) Expression sign
     ) {
@@ -125,11 +125,25 @@ public TypeResolution resolveType() {
         }
         var magnitude = children().get(0);
         var sign = children().get(1);
-        if (magnitude.dataType().isNumeric() == false) {
-            return new TypeResolution("Magnitude must be a numeric type");
+        TypeResolution resolution = TypeResolutions.isType(
+            magnitude,
+            t -> t.isNumeric() && t != DataType.UNSIGNED_LONG,
+            sourceText(),
+            TypeResolutions.ParamOrdinal.FIRST,
+            "numeric"
+        );
+        if (resolution.unresolved()) {
+            return resolution;
         }
-        if (sign.dataType().isNumeric() == false) {
-            return new TypeResolution("Sign must be a numeric type");
+        resolution = TypeResolutions.isType(
+            sign,
+            t -> t.isNumeric() && t != DataType.UNSIGNED_LONG,
+            sourceText(),
+            TypeResolutions.ParamOrdinal.SECOND,
+            "numeric"
+        );
+        if (resolution.unresolved()) {
+            return resolution;
         }
         // The return type is the same as the magnitude type, so we can use it directly.
         dataType = magnitude.dataType();

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/TestCaseSupplier.java

@@ -47,6 +47,7 @@
 import java.util.function.UnaryOperator;
 import java.util.stream.Collectors;
 
+import static org.elasticsearch.xpack.esql.core.util.NumericUtils.UNSIGNED_LONG_MAX;
 import static org.elasticsearch.xpack.esql.core.util.SpatialCoordinateTypes.CARTESIAN;
 import static org.elasticsearch.xpack.esql.core.util.SpatialCoordinateTypes.GEO;
 import static org.hamcrest.Matchers.equalTo;
@@ -357,6 +358,22 @@ public static List<TypedDataSupplier> getSuppliersForNumericType(DataType type,
         throw new IllegalArgumentException("bogus numeric type [" + type + "]");
     }
 
+    public static List<TypedDataSupplier> getSuppliersForNumericType(DataType type) {
+        if (type == DataType.INTEGER) {
+            return intCases(Integer.MIN_VALUE, Integer.MAX_VALUE, true);
+        }
+        if (type == DataType.LONG) {
+            return longCases(Long.MIN_VALUE, Long.MAX_VALUE, true);
+        }
+        if (type == DataType.UNSIGNED_LONG) {
+            return ulongCases(BigInteger.ZERO, UNSIGNED_LONG_MAX, true);
+        }
+        if (type == DataType.DOUBLE) {
+            return doubleCases(-Double.MAX_VALUE, Double.MAX_VALUE, true);
+        }
+        throw new IllegalArgumentException("bogus numeric type [" + type + "]");
+    }
+
     public static List<TestCaseSupplier> forBinaryComparisonWithWidening(
         NumericTypeTestConfigs<Boolean> typeStuff,
         String lhsName,

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/scalar/math/CopySignErrorTests.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.math;
+
+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 CopySignErrorTests extends ErrorsForCasesWithoutExamplesTestCase {
+    @Override
+    protected List<TestCaseSupplier> cases() {
+        return paramsToSuppliers(CopySignTests.parameters());
+    }
+
+    @Override
+    protected Expression build(Source source, List<Expression> args) {
+        return new CopySign(source, args.get(0), args.get(1));
+    }
+
+    @Override
+    protected Matcher<String> expectedTypeErrorMatcher(List<Set<DataType>> validPerPosition, List<DataType> signature) {
+        return equalTo(typeErrorMessage(true, validPerPosition, signature, (v, i) -> "numeric"));
+    }
+}