Deal with null responses coming back from server

.phive/phars.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phive xmlns="https://phar.io/phive">
-  <phar name="psalm" version="^4.13.1" installed="4.13.1" location="./tools/psalm.phar" copy="true"/>
+  <phar name="psalm" version="^4.17" installed="4.17.0" location="./tools/psalm.phar" copy="true"/>
   <phar name="php-cs-fixer" version="^3.3.2" installed="3.3.2" location="./tools/php-cs-fixer.phar" copy="true"/>
 </phive>

psalm.xml

@@ -2,7 +2,6 @@
 <psalm
     errorLevel="2"
     resolveFromConfigFile="true"
-    forbidEcho="true"
     strictBinaryOperands="true"
     phpVersion="8.0"
     allowStringToStandInForClass="true"
@@ -19,7 +18,4 @@
             <directory name="tests" />
         </ignoreFiles>
     </projectFiles>
-    <stubs>
-        <file name="stubs/SoapClient.phpstub" />
-    </stubs>
 </psalm>

src/AbusedClient.php

@@ -6,6 +6,7 @@
 
 use Soap\Engine\HttpBinding\SoapRequest;
 use Soap\Engine\HttpBinding\SoapResponse;
+use Soap\ExtSoapEngine\ErrorHandling\ExtSoapErrorHandler;
 use Soap\ExtSoapEngine\Exception\RequestException;
 use SoapClient;
 
@@ -63,7 +64,11 @@ public function doActualRequest(
         bool $oneWay = false
     ): string {
         $this->__last_request = $request;
-        $this->__last_response = (string) parent::__doRequest($request, $location, $action, $version, $oneWay);
+        $this->__last_response = (string) ExtSoapErrorHandler::handleNullResponse(
+            ExtSoapErrorHandler::handleInternalErrors(
+                fn (): ?string => parent::__doRequest($request, $location, $action, $version, $oneWay)
+            )
+        );
 
         return $this->__last_response;
     }

src/ErrorHandling/ExtSoapErrorHandler.php

@@ -0,0 +1,82 @@
+<?php
+declare(strict_types=1);
+
+namespace Soap\ExtSoapEngine\ErrorHandling;
+
+use Soap\ExtSoapEngine\Exception\RequestException;
+
+/**
+ * @psalm-internal Soap\ExtSoapEngine
+ */
+final class ExtSoapErrorHandler
+{
+    private function __construct()
+    {
+    }
+
+    /**
+     * @template T
+     *
+     * @param (callable(): T) $fun
+     *
+     * @return array{0: T, 1: ?string}
+     *
+     * @psalm-suppress MissingThrowsDocblock
+     */
+    public function __invoke(callable $fun): array
+    {
+        $lastMessage = null;
+        /** @psalm-suppress InvalidArgument */
+        set_error_handler(static function (int $_type, string $message) use (&$lastMessage) {
+            $lastMessage = $message;
+        });
+
+        try {
+            $value = $fun();
+
+            /** @var array{0: T, 1: ?string} $result */
+            $result = [$value, $lastMessage];
+
+            return $result;
+        } finally {
+            restore_error_handler();
+        }
+    }
+
+    /**
+     * @template T
+     *
+     * @param (callable(): T) $fun
+     *
+     * @return T
+     */
+    public static function handleInternalErrors(callable $fun)
+    {
+        [$result, $lastMessage] = (new self)($fun);
+
+        if ($lastMessage) {
+            throw RequestException::internalSoapError($lastMessage);
+        }
+
+        return $result;
+    }
+
+    /**
+     * @template T
+     *
+     * @param T $response
+     * @psalm-assert !null $response
+     *
+     * @return T
+     */
+    public static function handleNullResponse($response)
+    {
+        if ($response === null) {
+            throw RequestException::internalSoapError(
+                'An empty response got returned after contacting the SOAP server.'
+            );
+        }
+
+        return $response;
+    }
+}

src/Exception/RequestException.php

@@ -11,4 +11,9 @@ public static function noRequestWasMadeYet(): self
     {
         return new self('No request has been registered yet.');
     }
+
+    public static function internalSoapError(string $lastError): self
+    {
+        return new self('Internal ext-soap error: ' . $lastError);
+    }
 }

tests/Unit/ErrorHandling/ExtSoapErrorHandlerTest.php

@@ -0,0 +1,47 @@
+<?php
+declare(strict_types=1);
+
+namespace SoapTest\ExtSoapEngine\Unit\ErrorHandling;
+
+use PHPUnit\Framework\TestCase;
+use Soap\ExtSoapEngine\ErrorHandling\ExtSoapErrorHandler;
+use Soap\ExtSoapEngine\Exception\RequestException;
+
+final class ExtSoapErrorHandlerTest extends TestCase
+{
+    public function test_it_can_deal_with_null_responses(): void
+    {
+        $this->expectException(RequestException::class);
+
+        ExtSoapErrorHandler::handleNullResponse(null);
+    }
+
+    public function test_it_can_deal_with_non_null_responses(): void
+    {
+        $res = ExtSoapErrorHandler::handleNullResponse('hello');
+
+        static::assertSame('hello', $res);
+    }
+
+    public function test_it_can_detect_no_internal_errors_during_callback(): void
+    {
+        $res = ExtSoapErrorHandler::handleInternalErrors(
+            static fn () => 'hello'
+        );
+
+        static::assertSame($res, 'hello');
+    }
+
+    public function test_it_can_detect_internal_errors_during_callback(): void
+    {
+        $this->expectException(RequestException::class);
+        $this->expectExceptionMessage('hello');
+
+        ExtSoapErrorHandler::handleInternalErrors(
+            static function () {
+                trigger_error('hello');
+                return 'x';
+            }
+        );
+    }
+}