Only throw ContextException from receive, send, and join (#166)

src/Context/Context.php

@@ -16,8 +16,7 @@ interface Context extends Channel
     /**
      * @return TResult The data returned from the context.
      *
-     * @throws ContextException If the context dies unexpectedly.
+     * @throws ContextException If the context exited with an uncaught exception or non-zero code.
-     * @throws ContextPanicError If the context throws an uncaught exception.
      */
     public function join(?Cancellation $cancellation = null): mixed;
 }

src/Context/Internal/AbstractContext.php

@@ -36,34 +36,33 @@ abstract class AbstractContext implements Context
         } catch (ChannelException $exception) {
             try {
                 $data = $this->join(new TimeoutCancellation(0.1));
-            } catch (ContextException|ChannelException|CancelledException) {
+            } catch (ChannelException|CancelledException) {
                 if (!$this->isClosed()) {
                     $this->close();
                 }
                 throw new ContextException(
-                    "The process stopped responding, potentially due to a fatal error or calling exit",
+                    "The context stopped responding, potentially due to a fatal error or calling exit",
-                    0,
+                    previous: $exception,
-                    $exception,
                 );
             }
 
-            throw new \Error(\sprintf(
+            throw new ContextException(\sprintf(
-                'Process unexpectedly exited when waiting to receive data with result: %s',
+                'Context unexpectedly exited when waiting to receive data with result: %s',
                 flattenArgument($data),
-            ), 0, $exception);
+            ), previous: $exception);
         }
 
         if (!$data instanceof ContextMessage) {
             if ($data instanceof ExitResult) {
                 $data = $data->getResult();
 
-                throw new \Error(\sprintf(
+                throw new ContextException(\sprintf(
-                    'Process unexpectedly exited when waiting to receive data with result: %s',
+                    'Context unexpectedly exited when waiting to receive data with result: %s',
                     flattenArgument($data),
                 ));
             }
 
-            throw new \Error(\sprintf(
+            throw new ContextException(\sprintf(
                 'Unexpected data type from context: %s',
                 flattenArgument($data),
             ));
@@ -79,19 +78,19 @@ abstract class AbstractContext implements Context
         } catch (ChannelException $exception) {
             try {
                 $data = $this->join(new TimeoutCancellation(0.1));
-            } catch (ContextException|ChannelException|CancelledException) {
+            } catch (ChannelException|CancelledException) {
                 if (!$this->isClosed()) {
                     $this->close();
                 }
+
                 throw new ContextException(
-                    "The process stopped responding, potentially due to a fatal error or calling exit",
+                    "The context stopped responding, potentially due to a fatal error or calling exit",
-                    0,
+                    previous: $exception,
-                    $exception,
                 );
             }
 
-            throw new \Error(\sprintf(
+            throw new ContextException(\sprintf(
-                'Process unexpectedly exited when sending data with result: %s',
+                'Context unexpectedly exited when sending data with result: %s',
                 flattenArgument($data),
             ), 0, $exception);
         }
@@ -115,7 +114,7 @@ abstract class AbstractContext implements Context
     protected function receiveExitResult(?Cancellation $cancellation = null): ExitResult
     {
         if ($this->channel->isClosed()) {
-            throw new ContextException("The context has already closed");
+            throw new ContextException("The context has already closed without providing a result");
         }
 
         try {
@@ -126,7 +125,7 @@ abstract class AbstractContext implements Context
             if (!$this->isClosed()) {
                 $this->close();
             }
-            throw new ContextException("Failed to receive result from context", 0, $exception);
+            throw new ContextException("Failed to receive result from context", previous: $exception);
         }
 
         if (!$data instanceof ExitResult) {
@@ -135,13 +134,13 @@ abstract class AbstractContext implements Context
             }
 
             if ($data instanceof ContextMessage) {
-                throw new \Error(\sprintf(
+                $data = $data->getMessage();
-                    "The context sent data instead of exiting: %s",
-                    flattenArgument($data),
-                ));
             }
 
-            throw new \Error("Did not receive an exit result from context");
+            throw new ContextException(\sprintf(
+                "The context sent data instead of exiting: %s",
+                flattenArgument($data),
+            ));
         }
 
         $this->channel->close();

src/Context/Internal/ExitFailure.php

@@ -2,6 +2,7 @@
 
 namespace Amp\Parallel\Context\Internal;
 
+use Amp\Parallel\Context\ContextException;
 use Amp\Parallel\Context\ContextPanicError;
 use function Amp\Parallel\Context\flattenThrowableBacktrace;
 
@@ -42,11 +43,16 @@ final class ExitFailure implements ExitResult
     }
 
     /**
-     * @throws ContextPanicError
+     * @throws ContextException
      */
     public function getResult(): never
     {
-        throw $this->createException();
+        $exception = $this->createException();
+
+        throw new ContextException(
+            'Process exited with an uncaught exception: ' . $exception->getMessage(),
+            previous: $exception,
+        );
     }
 
     private function createException(): ContextPanicError

src/Context/Internal/ExitResult.php

@@ -2,7 +2,7 @@
 
 namespace Amp\Parallel\Context\Internal;
 
-use Amp\Parallel\Context\ContextPanicError;
+use Amp\Parallel\Context\ContextException;
 
 /**
  * @internal
@@ -13,7 +13,7 @@ interface ExitResult
     /**
      * @return TValue Return value of the callable given to the execution context.
      *
-     * @throws ContextPanicError If the context exited with an uncaught exception.
+     * @throws ContextException If the context exited with an uncaught exception.
      */
     public function getResult(): mixed;
 }

test/Context/AbstractContextTest.php

@@ -5,7 +5,6 @@ namespace Amp\Parallel\Test\Context;
 use Amp\CancelledException;
 use Amp\Parallel\Context\Context;
 use Amp\Parallel\Context\ContextException;
-use Amp\Parallel\Context\ContextPanicError;
 use Amp\PHPUnit\AsyncTestCase;
 use Amp\TimeoutCancellation;
 use function Amp\async;
@@ -26,7 +25,7 @@ abstract class AbstractContextTest extends AsyncTestCase
 
     public function testFailingProcess(): void
     {
-        $this->expectException(ContextPanicError::class);
+        $this->expectException(ContextException::class);
         $this->expectExceptionMessage('No string provided');
 
         $context = $this->createContext(__DIR__ . "/Fixtures/test-process.php");
@@ -35,40 +34,33 @@ abstract class AbstractContextTest extends AsyncTestCase
 
     public function testThrowingProcessOnReceive(): void
     {
-        $this->expectException(ContextPanicError::class);
+        $this->expectException(ContextException::class);
         $this->expectExceptionMessage('Test message');
 
         $context = $this->createContext(__DIR__ . "/Fixtures/throwing-process.php");
 
         $cancellation = new TimeoutCancellation(0.1);
 
-        try {
+        $context->receive($cancellation);
-            $context->receive($cancellation);
+
-            self::fail('Receiving should have failed');
+        self::fail('Receiving should have failed');
-        } catch (ContextException) {
-            $context->join($cancellation);
-        }
     }
 
     public function testThrowingProcessOnSend(): void
     {
-        $this->expectException(ContextPanicError::class);
+        $this->expectException(ContextException::class);
-        $this->expectExceptionMessage('Test message');
 
         $context = $this->createContext(__DIR__ . "/Fixtures/throwing-process.php");
-        delay(1);
+        delay(1); // Give process time to start.
 
-        try {
+        $context->send(1);
-            $context->send(1);
+
-            self::fail('Sending should have failed');
+        self::fail('Sending should have failed');
-        } catch (ContextException) {
-            $context->join(new TimeoutCancellation(1));
-        }
     }
 
     public function testInvalidScriptPath(): void
     {
-        $this->expectException(ContextPanicError::class);
+        $this->expectException(ContextException::class);
         $this->expectExceptionMessage("No script found at '../test-process.php'");
 
         $context = $this->createContext("../test-process.php");
@@ -77,7 +69,7 @@ abstract class AbstractContextTest extends AsyncTestCase
 
     public function testInvalidResult(): void
     {
-        $this->expectException(ContextPanicError::class);
+        $this->expectException(ContextException::class);
         $this->expectExceptionMessage('The given data could not be serialized');
 
         $context = $this->createContext(__DIR__ . "/Fixtures/invalid-result-process.php");
@@ -86,7 +78,7 @@ abstract class AbstractContextTest extends AsyncTestCase
 
     public function testNoCallbackReturned(): void
     {
-        $this->expectException(ContextPanicError::class);
+        $this->expectException(ContextException::class);
         $this->expectExceptionMessage('did not return a callable function');
 
         $context = $this->createContext(__DIR__ . "/Fixtures/no-callback-process.php");
@@ -95,7 +87,7 @@ abstract class AbstractContextTest extends AsyncTestCase
 
     public function testParseError(): void
     {
-        $this->expectException(ContextPanicError::class);
+        $this->expectException(ContextException::class);
         $this->expectExceptionMessage('contains a parse error');
 
         $context = $this->createContext(__DIR__ . "/Fixtures/parse-error-process.inc");

test/Context/Internal/ExitFailureTest.php

@@ -2,7 +2,7 @@
 
 namespace Amp\Parallel\Test\Context\Internal;
 
-use Amp\Parallel\Context\ContextPanicError;
+use Amp\Parallel\Context\ContextException;
 use Amp\Parallel\Context\Internal\ExitFailure;
 use Amp\PHPUnit\AsyncTestCase;
 
@@ -15,7 +15,7 @@ class ExitFailureTest extends AsyncTestCase
         $result = new ExitFailure($exception);
         try {
             $result->getResult();
-        } catch (ContextPanicError $caught) {
+        } catch (ContextException $caught) {
             self::assertGreaterThan(0, \stripos($caught->getMessage(), $message));
             return;
         }