**Build scan:**
https://gradle-enterprise.elastic.co/s/fvg2knbi424p4/tests/:x-pack:plugin:esql:test/org.elasticsearch.xpack.esql.expression.function.scalar.conditional.LeastTests/testEvaluateInManyThreads%20%7BTestCase=(%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E)%20null%20in%204%7D
**Reproduction lines:**
```
gradlew ':x-pack:plugin:esql:test' --tests "org.elasticsearch.xpack.esql.expression.function.scalar.conditional.GreatestTests.testEvaluateInManyThreads {TestCase=(<mv_integer>) null in 0}" -Dtests.seed=BCCD8A2AFCEA37CB -Dtests.locale=zh -Dtests.timezone=Europe/Guernsey -Druntime.java=21

gradlew ':x-pack:plugin:esql:test' --tests "org.elasticsearch.xpack.esql.expression.function.scalar.conditional.LeastTests.testEvaluateInManyThreads {TestCase=(<keyword>, <keyword>, <keyword>, <keyword>, <keyword>, <keyword>, <keyword>) null in 4}" -Dtests.seed=BCCD8A2AFCEA37CB -Dtests.locale=lt -Dtests.timezone=Indian/Christmas -Druntime.java=21

 gradlew ':x-pack:plugin:esql:test' --tests "org.elasticsearch.xpack.esql.expression.function.scalar.conditional.GreatestTests.testEvaluateInManyThreads {TestCase=(<mv_integer>) null in 0}" -Dtests.seed=BCCD8A2AFCEA37CB -Dtests.locale=zh -Dtests.timezone=Europe/Guernsey -Druntime.java=21
```

**Applicable branches:**
main

**Reproduces locally?:**
Yes

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.xpack.esql.expression.function.scalar.conditional.LeastTests&tests.test=testEvaluateInManyThreads%20%7BTestCase%3D(%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E,%20%3Ckeyword%3E)%20null%20in%204%7D


**Failure excerpt:**
```
org.elasticsearch.xpack.esql.expression.function.scalar.conditional.GreatestTests > classMethod FAILED
    java.lang.AssertionError: expected:<[boolean, double, integer, ip, keyword, long, text, version]> but was:<[integer]>


```
x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/AbstractFunctionTestCase.java
import org.elasticsearch.indices.CrankyCircuitBreakerService;
import org.elasticsearch.logging.LogManager;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.xpack.esql.evaluator.EvalMapper;
import org.elasticsearch.xpack.esql.expression.function.scalar.conditional.Greatest;
import org.elasticsearch.xpack.esql.expression.function.scalar.nulls.Coalesce;
import org.elasticsearch.xpack.esql.optimizer.FoldNull;
import org.elasticsearch.xpack.esql.planner.Layout;
import org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner;
import org.elasticsearch.xpack.esql.type.EsqlDataTypes;
import org.elasticsearch.xpack.ql.expression.Expression;
import org.elasticsearch.xpack.ql.expression.FieldAttribute;
import org.elasticsearch.xpack.ql.expression.Literal;
import org.elasticsearch.xpack.ql.expression.TypeResolutions;
import org.elasticsearch.xpack.ql.expression.function.FunctionDefinition;
import org.elasticsearch.xpack.ql.tree.Source;
import org.elasticsearch.xpack.ql.type.DataType;
import org.elasticsearch.xpack.ql.type.DataTypes;
import org.elasticsearch.xpack.ql.type.EsField;
import org.elasticsearch.xpack.ql.util.StringUtils;
import org.elasticsearch.xpack.versionfield.Version;
import org.hamcrest.Matcher;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.time.Duration;
import java.time.Period;