Enhance StreamConnection

Also, fixes edge case error when StreamConnection::open()
was returning null instead of the Greeting object:

TypeError: Return value of Tarantool\Client\Connection\StreamConnection::open() must be an instance of Tarantool\Client\Connection\Greeting, null returned

src/Connection/StreamConnection.php

@@ -76,15 +76,9 @@ public static function create(string $uri, array $options = []) : self
             : self::createTcp($uri, $options);
     }
 
-    /**
-     * @see https://github.com/vimeo/psalm/issues/3021
-     * @psalm-suppress InvalidNullableReturnType
-     */
     public function open() : Greeting
     {
-        if (\is_resource($this->stream)) {
-            /** @see https://github.com/vimeo/psalm/issues/3021 */
-            /** @psalm-suppress NullableReturnStatement */
+        if ($this->greeting) {
             return $this->greeting;
         }
 
@@ -125,7 +119,7 @@ public function open() : Greeting
 
     public function close() : void
     {
-        if (\is_resource($this->stream)) {
+        if ($this->stream) {
             /** @psalm-suppress InvalidPropertyAssignmentValue */
             \fclose($this->stream);
         }
@@ -136,13 +130,12 @@ public function close() : void
 
     public function isClosed() : bool
     {
-        return !\is_resource($this->stream);
+        return !$this->stream;
     }
 
     public function send(string $data) : string
     {
-        /** @psalm-suppress PossiblyNullArgument */
-        if (!\fwrite($this->stream, $data)) {
+        if (!$this->stream || !\fwrite($this->stream, $data)) {
             throw new CommunicationFailed('Unable to write request');
         }
 

tests/Integration/Connection/ConnectionTest.php

@@ -13,12 +13,17 @@
 
 namespace Tarantool\Client\Tests\Integration\Connection;
 
+use Tarantool\Client\Exception\CommunicationFailed;
 use Tarantool\Client\Exception\ConnectionFailed;
 use Tarantool\Client\Exception\UnexpectedResponse;
 use Tarantool\Client\Request\PingRequest;
 use Tarantool\Client\Schema\Criteria;
 use Tarantool\Client\Schema\Operations;
+use Tarantool\Client\Tests\GreetingDataProvider;
 use Tarantool\Client\Tests\Integration\ClientBuilder;
+use Tarantool\Client\Tests\Integration\FakeServer\FakeServerBuilder;
+use Tarantool\Client\Tests\Integration\FakeServer\Handler\AtConnectionHandler;
+use Tarantool\Client\Tests\Integration\FakeServer\Handler\WriteHandler;
 use Tarantool\Client\Tests\Integration\TestCase;
 
 final class ConnectionTest extends TestCase
@@ -181,4 +186,32 @@ public function testUnexpectedResponse() : void
 
         self::fail(UnexpectedResponse::class.' was not thrown');
     }
+
+    public function testOpenConnectionHandlesTheMissingGreetingCorrectly() : void
+    {
+        $clientBuilder = ClientBuilder::createFromEnvForTheFakeServer();
+
+        FakeServerBuilder::create(
+            new AtConnectionHandler(1, new WriteHandler('')),
+            new AtConnectionHandler(2, new WriteHandler(GreetingDataProvider::generateGreeting()))
+        )
+            ->setUri($clientBuilder->getUri())
+            ->start();
+
+        $client = $clientBuilder->build();
+        $connection = $client->getHandler()->getConnection();
+
+        try {
+            $connection->open();
+            self::fail('Connection not established');
+        } catch (CommunicationFailed $e) {
+            self::assertSame('Unable to read greeting', $e->getMessage());
+            // at that point the connection was successfully established,
+            // but the greeting message was not read
+        }
+
+        // the second call should correctly handle
+        // the missing greeting from the previous call
+        $connection->open();
+    }
 }

tests/Integration/FakeServer/Handler/AtConnectionHandler.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * This file is part of the Tarantool Client package.
+ *
+ * (c) Eugene Leonovich <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Tarantool\Client\Tests\Integration\FakeServer\Handler;
+
+class AtConnectionHandler implements Handler
+{
+    private $atConnectionNumber;
+    private $handler;
+    private $connectionCount = 0;
+
+    public function __construct(int $atConnectionNumber, Handler $handler)
+    {
+        $this->atConnectionNumber = $atConnectionNumber;
+        $this->handler = $handler;
+    }
+
+    public function __invoke($conn, string $sid) : ?bool
+    {
+        ++$this->connectionCount;
+
+        if ($this->connectionCount === $this->atConnectionNumber) {
+            return ($this->handler)($conn, $sid);
+        }
+
+        return null;
+    }
+}