PHP SoapServer ignores invalid enum value

request.xml

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="test-service-namespace">
    <SOAP-ENV:Body>
        <ns1:TestOperation>
            <ns1:firstArgument>
                <!-- Wrong enum -->
                <ns1:timeGroup>FooBar</ns1:timeGroup>
                <!-- Good enum -->
                <ns1:customerType>CHILD</ns1:customerType>
            </ns1:firstArgument>
        </ns1:TestOperation>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

service.wsdl.xml

<?xml version='1.0' encoding='UTF-8'?>
<wsdl:definitions
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
    targetNamespace="test-service-namespace"
    name="TestService">
    <wsdl:types>
        <xs:schema targetNamespace="test-service-namespace" elementFormDefault="qualified">
            <xs:simpleType name="TimeGroupEnum">
                <xs:restriction base="xs:string">
                    <xs:enumeration value="NOGROUP"/>
                    <xs:enumeration value="DAY"/>
                    <xs:enumeration value="WEEK"/>
                    <xs:enumeration value="MONTH"/>
                    <xs:enumeration value="QUARTER"/>
                    <xs:enumeration value="YEAR"/>
                </xs:restriction>
            </xs:simpleType>
            <xs:simpleType name="CustomerTypeEnum">
                <xs:restriction base="xs:string">
                    <xs:enumeration value="CHILD"/>
                    <xs:enumeration value="ADULT"/>
                </xs:restriction>
            </xs:simpleType>
            <xs:complexType name="TestStructure">
                <xs:sequence>
                    <xs:element name="timeGroup" type="tns:TimeGroupEnum"/>
                    <xs:element name="customerType" type="tns:CustomerTypeEnum"/>
                </xs:sequence>
            </xs:complexType>
            <xs:complexType name="TestOperation">
                <xs:sequence>
                    <xs:element name="firstArgument" type="tns:TestStructure"/>
                </xs:sequence>
            </xs:complexType>
            <xs:complexType name="TestOperationResponse">
                <xs:sequence>
                    <xs:element name="TestOperationResult" type="xs:string" minOccurs="0" nillable="true"/>
                </xs:sequence>
            </xs:complexType>
            <xs:element name="TestStructure" type="tns:TestStructure"/>
            <xs:element name="TestOperation" type="tns:TestOperation"/>
            <xs:element name="TestOperationResponse" type="tns:TestOperationResponse"/>            
        </xs:schema>
    </wsdl:types>
    <wsdl:message name="TestOperation">
        <wsdl:part name="TestOperation" element="tns:TestOperation"/>
    </wsdl:message>
    <wsdl:message name="TestOperationResponse">
        <wsdl:part name="TestOperationResponse" element="tns:TestOperationResponse"/>
    </wsdl:message>
    <wsdl:portType name="TestService">
        <wsdl:operation name="TestOperation" parameterOrder="TestOperation">
            <wsdl:input name="TestOperation" message="tns:TestOperation"/>
            <wsdl:output name="TestOperationResponse" message="tns:TestOperationResponse"/>
        </wsdl:operation>
    </wsdl:portType>
    <wsdl:binding name="TestService" type="tns:TestService">
        <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
        <wsdl:operation name="TestOperation">
            <soap:operation soapAction="TestOperation" style="document"/>
            <wsdl:input name="TestOperation">
                <soap:body use="literal"/>
            </wsdl:input>
            <wsdl:output name="TestOperationResponse">
                <soap:body use="literal"/>
            </wsdl:output>
        </wsdl:operation>
    </wsdl:binding>
    <wsdl:service name="TestService">
        <wsdl:port name="TestService" binding="tns:TestService">
            <soap:address location="http://localhost/test/service"/>
        </wsdl:port>
    </wsdl:service>
</wsdl:definitions>

test.php

<?php

// Проверка упадёт ли SOAP сервер от неправильного енума
// reportType из request.xml не соответствует определению service.wsdl.xml

function TestOperation($params)
{
    print_r($params);
    die();
    return array('TestOperationResult' => 42);
    return 42;
}

$soapServer = new SoapServer('service.wsdl.xml');

$soapServer->addFunction('TestOperation');

$request = file_get_contents('request.xml');

print_r($soapServer->handle($request));

die("\n\n");

Thanks for a detailed list of php soap server's limitations.