Prevented users from using "GET" method

- Throwing exception if client is constructed with request method other than "POST"
- Formatted code
- Improved code coverage

Author: mghoneimy

src/Client.php

@@ -3,6 +3,7 @@
 namespace GraphQL;
 
 use GraphQL\Exception\QueryError;
+use GraphQL\Exception\MethodNotSupportedException;
 use GraphQL\QueryBuilder\QueryBuilderInterface;
 use GraphQL\Util\GuzzleAdapter;
 use GuzzleHttp\Exception\ClientException;
@@ -70,6 +71,9 @@ public function __construct(
         $this->endpointUrl          = $endpointUrl;
         $this->httpClient           = $httpClient ?? new GuzzleAdapter(new \GuzzleHttp\Client($httpOptions));
         $this->httpHeaders          = $headers;
+        if ($requestMethod !== 'POST') {
+            throw new MethodNotSupportedException($requestMethod);
+        }
         $this->requestMethod        = $requestMethod;
     }
 

src/Exception/MethodNotSupportedException.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace GraphQL\Exception;
+
+use RunTimeException;
+
+/**
+ * Class MethodNotSupportedException
+ *
+ * @package GraphQL\Exception
+ */
+class MethodNotSupportedException extends RunTimeException
+{
+    public function __construct($requestMethod)
+    {
+        parent::__construct("Method \"$requestMethod\" is currently unsupported by client.");
+    }
+}

src/FieldTrait.php

@@ -42,7 +42,7 @@ protected function constructSelectionSet(): string
     {
         if (empty($this->selectionSet)) {
             return '';
-	}
+	    }
 
         $attributesString = " {" . PHP_EOL;
         $first            = true;

tests/ClientTest.php

@@ -4,6 +4,7 @@
 
 use GraphQL\Client;
 use GraphQL\Exception\QueryError;
+use GraphQL\Exception\MethodNotSupportedException;
 use GraphQL\QueryBuilder\QueryBuilder;
 use GraphQL\RawObject;
 use GuzzleHttp\Exception\ClientException;
@@ -47,6 +48,8 @@ protected function setUp(): void
     /**
      * @covers \GraphQL\Client::__construct
      * @covers \GraphQL\Client::runRawQuery
+     * @covers \GraphQL\Util\GuzzleAdapter::__construct
+     * @covers \GraphQL\Util\GuzzleAdapter::sendRequest
      */
     public function testConstructClient()
     {
@@ -74,9 +77,6 @@ public function testConstructClient()
         $client = new Client('', ['Authorization' => 'Basic xyz'], ['handler' => $handler, 'headers' => [ 'Authorization' => 'Basic zyx', 'User-Agent' => 'test' ]]);
         $client->runRawQuery('query_string');
 
-        $client = new Client('', ['Authorization' => 'Basic xyz'], ['handler' => $handler, 'headers' => [ 'Authorization' => 'Basic zyx', 'User-Agent' => 'test' ]], null, 'GET');
-        $client->runRawQuery('query_string');
-
         /** @var Request $firstRequest */
         $firstRequest = $container[0]['request'];
         $this->assertEquals('{"query":"query_string","variables":{}}', $firstRequest->getBody()->getContents());
@@ -100,10 +100,16 @@ public function testConstructClient()
         $this->assertNotEmpty($fourthRequest->getHeader('User-Agent'));
         $this->assertEquals(['Basic zyx'], $fourthRequest->getHeader('Authorization'));
         $this->assertEquals(['test'], $fourthRequest->getHeader('User-Agent'));
+    }
 
-        /** @var Request $fifthRequest */
-        $fifthRequest = $container[4]['request'];
-        $this->assertSame('GET', $fifthRequest->getMethod());
+    /**
+     * @covers \GraphQL\Client::__construct
+     * @covers \GraphQL\Exception\MethodNotSupportedException
+     */
+    public function testConstructClientWithGetRequestMethod()
+    {
+        $this->expectException(MethodNotSupportedException::class);
+        $client = new Client('', [], [], null, 'GET');
     }
 
     /**

tests/QueryTest.php

@@ -48,6 +48,7 @@ public function testEmptyArguments(Query $query)
 
     /**
      * @covers \GraphQL\Query::__toString
+     * @covers FieldTrait::constructSelectionSet
      */
     public function testQueryWithoutFieldName()
     {