Fix ResourceOutputStream closed detection (#60)

The previous mechanism with feof doesn't work for systemd launched processes.

Fixes #58.

lib/ResourceOutputStream.php

@@ -71,7 +71,7 @@ public function __construct($stream, int $chunkSize = null)
                         continue;
                     }
 
-                    if (!\is_resource($stream) || @\feof($stream)) {
+                    if (!\is_resource($stream) || (($metaData = @\stream_get_meta_data($stream)) && $metaData['eof'])) {
                         throw new StreamException("The stream was closed by the peer");
                     }
 
@@ -179,8 +179,8 @@ private function send(string $data, bool $end = false): Promise
                 return new Success(0);
             }
 
-            if (!\is_resource($this->resource) || @\feof($this->resource)) {
-                return new Failure(new StreamException("The stream was closed by the peer"));
+            if (!\is_resource($this->resource) || (($metaData = @\stream_get_meta_data($this->resource)) && $metaData['eof'])) {
+                throw new StreamException("The stream was closed by the peer");
             }
 
             // Error reporting suppressed since fwrite() emits E_WARNING if the pipe is broken or the buffer is full.

test/ResourceOutputStreamTest.php

@@ -44,7 +44,7 @@ public function testBrokenPipe()
         \fclose($b);
 
         $this->expectException(StreamException::class);
-        $this->expectExceptionMessage("The stream was closed by the peer");
+        $this->expectExceptionMessage("Failed to write to stream after multiple attempts; fwrite(): send of 6 bytes failed with errno=32 Broken pipe");
         wait($stream->write("foobar"));
     }
 
@@ -60,7 +60,7 @@ public function testClosedRemoteSocket()
         \fclose($b);
 
         $this->expectException(StreamException::class);
-        $this->expectExceptionMessage("The stream was closed by the peer");
+        $this->expectExceptionMessage("Failed to write to stream after multiple attempts; fwrite(): send of 6 bytes failed with errno=32 Broken pipe");
 
         // The first write still succeeds somehow...
         wait($stream->write("foobar"));