Added provider fetch exception handler to ImportConnector

src/Connector/ConnectionContext.php

@@ -8,8 +8,20 @@ final class ConnectionContext
 {
     private $mustCache;
 
+    /**
+     * User-defined exception handler called when a recoverable exception is thrown by Connector::fetch().
+     *
+     * @var callable
+     */
     private $fetchExceptionHandler;
 
+    /**
+     * Provider-defined exception handler called when a recoverable exception is thrown by Connector::fetch().
+     *
+     * @var callable
+     */
+    private $providerFetchExceptionHandler;
+
     private $maxFetchAttempts;
 
     public function __construct($mustCache, callable $fetchExceptionHandler, $maxFetchAttempts)
@@ -47,9 +59,30 @@ function (\Exception $exception) {
                     throw $exception;
                 }
 
+                // Call provider's exception handler, if defined.
+                if ($this->providerFetchExceptionHandler) {
+                    call_user_func($this->providerFetchExceptionHandler, $exception);
+                }
+
                 // TODO Clone exception handler to avoid persisting state between calls.
                 call_user_func($this->fetchExceptionHandler, $exception);
             }
         );
     }
+
+    /**
+     * Sets an exception handler to be called when a recoverable exception is thrown by Connector::fetch().
+     *
+     * This handler is intended to be set by provider resources only and is called before the user-defined handler.
+     *
+     * @param callable $providerFetchExceptionHandler Exception handler.
+     */
+    public function setProviderFetchExceptionHandler(callable $providerFetchExceptionHandler)
+    {
+        if ($this->providerFetchExceptionHandler !== null) {
+            throw new \LogicException('Cannot set provider fetch exception handler: already set!');
+        }
+
+        $this->providerFetchExceptionHandler = $providerFetchExceptionHandler;
+    }
 }

src/Connector/ImportConnector.php

@@ -39,4 +39,14 @@ public function getWrappedConnector()
     {
         return $this->connector;
     }
+
+    /**
+     * Sets the exception handler to be called when a recoverable exception is thrown by Connector::fetch().
+     *
+     * @param callable $exceptionHandler Exception handler.
+     */
+    public function setExceptionHandler(callable $exceptionHandler)
+    {
+        $this->context->setProviderFetchExceptionHandler($exceptionHandler);
+    }
 }

test/Integration/Porter/PorterTest.php

@@ -12,6 +12,7 @@
 use ScriptFUSION\Porter\Connector\ConnectionContext;
 use ScriptFUSION\Porter\Connector\Connector;
 use ScriptFUSION\Porter\Connector\ConnectorOptions;
+use ScriptFUSION\Porter\Connector\ImportConnector;
 use ScriptFUSION\Porter\Connector\RecoverableConnectorException;
 use ScriptFUSION\Porter\ImportException;
 use ScriptFUSION\Porter\Porter;
@@ -303,6 +304,36 @@ public function testCustomFetchExceptionHandler()
         $this->porter->import($this->specification);
     }
 
+    /**
+     * Tests that when a provider fetch exception handler is specified and the connector throws a recoverable
+     * exception, the handler is called before the user handler.
+     */
+    public function testCustomProviderFetchExceptionHandler()
+    {
+        $this->specification->setFetchExceptionHandler(function () {
+            throw new \LogicException('This exception must not be thrown!');
+        });
+
+        $this->arrangeConnectorException($connectorException =
+            new RecoverableConnectorException('This exception is caught by the provider handler.'));
+
+        $this->resource
+            ->shouldReceive('fetch')
+            ->andReturnUsing(function (ImportConnector $connector) use ($connectorException) {
+                $connector->setExceptionHandler(function (\Exception $exception) use ($connectorException) {
+                    self::assertSame($connectorException, $exception);
+
+                    throw new \RuntimeException('This exception is thrown by the provider handler.');
+                });
+
+                yield $connector->fetch('foo');
+            })
+        ;
+
+        $this->setExpectedException(\RuntimeException::class);
+        $this->porter->importOne($this->specification);
+    }
+
     #endregion
 
     public function testFilter()

test/Unit/Porter/Connector/ImportConnectorTest.php

@@ -89,4 +89,20 @@ public function testGetWrappedConnector()
 
         self::assertSame($wrappedConnector, $connector->getWrappedConnector());
     }
+
+    /**
+     * Tests that setting the provider exception handler twice produces an exception the second time.
+     */
+    public function testSetExceptionHandlerTwice()
+    {
+        $connector = new ImportConnector(
+            $wrappedConnector = \Mockery::mock(Connector::class),
+            FixtureFactory::buildConnectionContext()
+        );
+
+        $connector->setExceptionHandler([$this, __FUNCTION__]);
+
+        $this->setExpectedException(\LogicException::class);
+        $connector->setExceptionHandler([$this, __FUNCTION__]);
+    }
 }