ensure rawheaders is not whitespace

Author: James Galecki

src/Util/Http.php

@@ -3,6 +3,7 @@
 namespace TraderInteractive\Util;
 
 use Exception;
+use InvalidArgumentException;
 
 /**
  * Static class with various HTTP related functions.
@@ -47,6 +48,10 @@ final class Http
      */
     public static function parseHeaders(string $rawHeaders) : array
     {
+        if (empty($rawHeaders)) {
+            throw new InvalidArgumentException('$rawHeaders cannot be whitespace');
+        }
+
         $headers = [];
         $rawHeaders = preg_replace("/\r\n[\t ]+/", ' ', trim($rawHeaders));
         $fields = explode("\r\n", $rawHeaders);

tests/Util/HttpTest.php

@@ -97,6 +97,23 @@ public function parseHeadersMethodAndUrlSet()
         $this->assertSame($expected, $result);
     }
 
+    /**
+     * Verifies that the rawHeaders string cannot be whitespace.
+     *
+     * @test
+     * @group unit
+     * @covers ::parseHeaders
+     *
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage $rawHeaders cannot be whitespace
+     *
+     * @return void
+     */
+    public function parseHeadersWhitespace()
+    {
+        Http::parseHeaders('');
+    }
+
     /**
      * @test
      * @covers ::buildQueryString