Fixed normalizing headers in HeadersConstraint (#16)

Author: slavcodev

src/PhpUnit/HeadersConstraint.php

@@ -57,7 +57,7 @@ protected function matches($actualHeaders)
         foreach ($this->expectedHeadersSchemas as $name => $expectedSchema) {
             if (isset($actualHeaders[$name])) {
                 $errors = $this->validator->validate(
-                    $this->normalizeHeaderValue($actualHeaders[$name]),
+                    $this->normalizeHeaderValue($actualHeaders[$name], $expectedSchema->type),
                     $expectedSchema,
                     $name
                 );
@@ -110,18 +110,25 @@ private static function normalizeJsonSchema($schema)
     }
 
     /**
-     * Ensure header value is array.
+     * The PSR-7 says that the header values MUST be an array of strings,
+     * but OpenAPI allow scalar values. So if scalar value expected,
+     * we try to cast array to scalar, using first element.
      *
-     * @param mixed $value
+     * @param array $value
+     * @param string $type
      *
      * @return array
      */
-    private static function normalizeHeaderValue($value)
+    private static function normalizeHeaderValue(array $value, $type)
     {
-        if (is_string($value) && strpos($value, ',') !== false) {
-            return preg_split('#\s*,\s*#', $value, -1, PREG_SPLIT_NO_EMPTY);
-        } else {
-            return $value;
+        if ($type !== 'array') {
+            $value = reset($value) ?: null;
+
+            if (is_numeric($value)) {
+                $value += 0;
+            }
         }
+
+        return $value;
     }
 }

tests/PhpUnit/HeadersConstraintTest.php

@@ -65,12 +65,12 @@ public function passUnexpectedValue()
     /**
      * @test
      */
-    public function AssertValidHeaders()
+    public function assertValidHeaders()
     {
         $headers = [
-            'Content-Type' => 'application/json',
-            'Allow' => 'OPTIONS, HEAD',
-            'X-Timestamp' => time(),
+            'Content-Type' => ['application/json'],
+            'Allow' => ['OPTIONS', 'HEAD'],
+            'X-Timestamp' => [time()],
         ];
 
         $this->assertThat($headers, $this->constraint);
@@ -107,15 +107,15 @@ public function provideInvalidHeaders()
             'Missing required header' => [
                 [],
             ],
-            '[Allow] String value found, but an array is required' => [
+            '[Allow] There must be a minimum of 2 items in the array' => [
                 [
-                    'Content-Type' => 'application/json',
-                    'Allow' => 'OPTIONS',
+                    'Content-Type' => ['application/json'],
+                    'Allow' => ['OPTIONS'],
                 ],
             ],
             '[X-Timestamp] String value found, but an integer is required' => [
                 [
-                    'X-Timestamp' => 'foo',
+                    'X-Timestamp' => ['foo'],
                 ],
             ],
         ];