Add string in map binary operator to core extension

src/Extension/Core/BinaryOperator/Handler/InOperator/StringMapHandler.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cel\Extension\Core\BinaryOperator\Handler\InOperator;
+
+use Cel\Exception\InternalException;
+use Cel\Operator\BinaryOperatorOverloadHandlerInterface;
+use Cel\Syntax\Binary\BinaryExpression;
+use Cel\Util\OperandUtil;
+use Cel\Value\BooleanValue;
+use Cel\Value\MapValue;
+use Cel\Value\StringValue;
+use Cel\Value\Value;
+use Override;
+use Psl\Iter;
+
+final readonly class StringMapHandler implements BinaryOperatorOverloadHandlerInterface
+{
+    /**
+     * @param BinaryExpression $expression The binary expression being evaluated.
+     * @param Value $left The evaluated left operand.
+     * @param Value $right The evaluated right operand.
+     *
+     * @return Value The result of the binary operation.
+     *
+     * @throws InternalException If operand type assertion fails.
+     */
+    #[Override]
+    public function __invoke(BinaryExpression $expression, Value $left, Value $right): Value
+    {
+        $left = OperandUtil::assertLeft($left, StringValue::class);
+        $right = OperandUtil::assertRight($right, MapValue::class);
+
+        return new BooleanValue(Iter\contains_key($right->value, $left->value));
+    }
+}

src/Extension/Core/BinaryOperator/InOperator.php

@@ -14,6 +14,7 @@
 use Cel\Extension\Core\BinaryOperator\Handler\InOperator\MessageListHandler;
 use Cel\Extension\Core\BinaryOperator\Handler\InOperator\NullListHandler;
 use Cel\Extension\Core\BinaryOperator\Handler\InOperator\StringListHandler;
+use Cel\Extension\Core\BinaryOperator\Handler\InOperator\StringMapHandler;
 use Cel\Extension\Core\BinaryOperator\Handler\InOperator\TimestampListHandler;
 use Cel\Extension\Core\BinaryOperator\Handler\InOperator\UnsignedIntegerListHandler;
 use Cel\Operator\BinaryOperatorOverloadInterface;
@@ -44,5 +45,6 @@ public function getOverloads(): iterable
         yield [ValueKind::Message, ValueKind::List] => new MessageListHandler();
         yield [ValueKind::Timestamp, ValueKind::List] => new TimestampListHandler();
         yield [ValueKind::Duration, ValueKind::List] => new DurationListHandler();
+        yield [ValueKind::String, ValueKind::Map] => new StringMapHandler();
     }
 }

tests/Runtime/RuntimeTest.php

@@ -59,6 +59,25 @@ public static function provideEvaluationCases(): iterable
             new BooleanValue(true),
         ];
 
+        yield 'Form: field in answers' => [
+            '\'field\' in answers',
+            [
+                'answers' => [
+                    'field' => 'available',
+                ],
+            ],
+            new BooleanValue(true),
+        ];
+        yield 'Form: field not in answers' => [
+            '\'field\' in answers',
+            [
+                'answers' => [
+                    'foo' => 'bar',
+                ],
+            ],
+            new BooleanValue(false),
+        ];
+
         yield 'RBAC: owner access' => [
             'user.id == resource.owner_id',
             [