Throw InvalidRequest exception on invalid CURL request

README.md

@@ -147,6 +147,9 @@ var_dump(
 );
 ```
 
+If there is an issues with the request, such as misconfigured CURL SSL options, an `InvalidRequest` will be thrown
+with message from CURL on why the request failed. Use the message as a hit to troubleshooting steps of your environment. 
+
 <a name="usage"></a>
 # Usage
 

lib/Client.php

@@ -13,6 +13,8 @@
 
 namespace SendGrid;
 
+use SendGrid\Exception\InvalidRequest;
+
 /**
  *
  * Class Client
@@ -453,6 +455,7 @@ private function retryRequest(array $responseHeaders, $method, $url, $body, $hea
      * @param bool   $retryOnLimit should retry if rate limit is reach?
      *
      * @return Response object
+     * @throws InvalidRequest
      */
     public function makeRequest($method, $url, $body = null, $headers = null, $retryOnLimit = false)
     {
@@ -463,6 +466,10 @@ public function makeRequest($method, $url, $body = null, $headers = null, $retry
         curl_setopt_array($channel, $options);
         $content = curl_exec($channel);
 
+        if ($content === false) {
+            throw new InvalidRequest(curl_error($channel), curl_errno($channel));
+        }
+
         $response = $this->parseResponse($channel, $content);
 
         if ($response->statusCode() === self::TOO_MANY_REQUESTS_HTTP_CODE && $retryOnLimit) {

lib/Exception/InvalidRequest.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * HTTP Client library
+ *
+ * @author    Matt Bernier <[email protected]>
+ * @author    Elmer Thomas <[email protected]>
+ * @copyright 2018 SendGrid
+ * @license   https://opensource.org/licenses/MIT The MIT License
+ * @version   GIT: <git_id>
+ * @link      http://packagist.org/packages/sendgrid/php-http-client
+ */
+namespace SendGrid\Exception;
+
+use Throwable;
+
+/**
+ * Class InvalidHttpRequest
+ *
+ * Thrown when invalid payload was constructed, which could not reach SendGrid server.
+ *
+ * @package SendGrid\Exceptions
+ */
+class InvalidRequest extends \Exception
+{
+    public function __construct(
+        $message = "",
+        $code = 0,
+        Throwable $previous = null
+    ) {
+        $message = 'Could not send request to server. '.
+            'CURL error '.$code.': '.$message;
+        parent::__construct($message, $code, $previous);
+    }
+
+}

test/unit/ClientTest.php

@@ -3,6 +3,7 @@
 namespace SendGrid\Test;
 
 use SendGrid\Client;
+use SendGrid\Exception\InvalidRequest;
 
 class ClientTest extends \PHPUnit_Framework_TestCase
 {
@@ -195,6 +196,14 @@ public function testCreateCurlOptionsWithBodyAndHeaders()
         ], $result);
     }
 
+
+    public function testThrowExceptionOnInvalidCall()
+    {
+        $this->setExpectedException(InvalidRequest::class);
+        $client = new Client('invalid://url',['User-Agent: Custom-Client 1.0']);
+        $client->get();
+    }
+
     /**
      * @param object $obj
      * @param string $name