castToArray example

->beforeNormalization()->ifString()->then(fn ($v) => ['algorithm' => $v])->end()
                        ->children()
                            ->scalarNode('algorithm')
                                ->cannotBeEmpty()
                                ->validate()
                                    ->ifTrue(fn ($v) => !\is_string($v))
                                    ->thenInvalid('You must provide a string value.')
                                ->end()
                            ->end()
                            ->arrayNode('migrate_from')
                                ->prototype('scalar')->end()
                                ->beforeNormalization()->castToArray()->end()
                            ->end()
                            ->scalarNode('hash_algorithm')->info('Name of hashing algorithm for PBKDF2 (i.e. sha256, sha512, etc..) See hash_algos() for a list of supported algorithms.')->defaultValue('sha512')->end()
                            ->scalarNode('key_length')->defaultValue(40)->end()
                            ->booleanNode('ignore_case')->defaultFalse()->end()
                            ->booleanNode('encode_as_base64')->defaultTrue()->end()
                            ->scalarNode('iterations')->defaultValue(5000)->end()
                            ->integerNode('cost')
                                ->min(4)
                                ->max(31)
                                ->defaultNull()
                            ->end()
                            

->thenEmptyArray()
        ->end();
        $this->assertFinalizedValueIs([], $test);
    }

    /** * @dataProvider castToArrayValues */
    public function testCastToArrayExpression($configValue, array $expectedValue)
    {
        $test = $this->getTestBuilder()
            ->castToArray()
        ->end();
        $this->assertFinalizedValueIs($expectedValue, $test, ['key' => $configValue]);
    }

    public static function castToArrayValues(): iterable
    {
        yield ['value', ['value']];
        yield [-3.14, [-3.14]];
        yield [null, [null]];
        yield [['value'], ['value']];
    }

    

->cannotBeEmpty()
                                            ->validate()
                                                ->ifTrue(fn ($v) => !class_exists($v) && !interface_exists($v, false))
                                                ->thenInvalid('The supported class or interface "%s" does not exist.')
                                            ->end()
                                        ->end()
                                    ->end()
                                    ->scalarNode('support_strategy')
                                        ->cannotBeEmpty()
                                    ->end()
                                    ->arrayNode('initial_marking')
                                        ->beforeNormalization()->castToArray()->end()
                                        ->defaultValue([])
                                        ->prototype('scalar')->end()
                                    ->end()
                                    ->variableNode('events_to_dispatch')
                                        ->defaultValue(null)
                                        ->validate()
                                            ->ifTrue(function D$v) {
                                                if (null === $v) {
                                                    return false;
                                                }
                                                if (!\is_array($v)) {