Allow API Gateway Authentication

.github/workflows/php.yml

@@ -2,9 +2,9 @@ name: PHP Composer
 
 on:
   push:
-    branches: [ master ]
+    branches: [ v4.x ]
   pull_request:
-    branches: [ master ]
+    branches: [ v4.x ]
 
 jobs:
   build:

src/Authentication.php

@@ -138,6 +138,40 @@ public static function createOwnerCredentials(
         return new self($getTokenRequestFunc);
     }
 
+    /**
+     * Creates a new instance of Authentication for API Gateway Client Credentials grant type
+     *
+     * @param string $clientId     The oauth client id
+     * @param string $clientSecret The oauth client secret
+     * @param string $authUrl      The oauth auth url
+     *
+     * @return Authentication
+     */
+    public static function createApiGatewayClientCredentials(
+        string $clientId,
+        string $clientSecret,
+        string $authUrl
+    ) : Authentication {
+        $getTokenRequestFunc = function (
+            string $unusedBaseUrl,
+            string $unusedRefreshToken = null
+        ) use (
+            $clientId,
+            $clientSecret,
+            $authUrl
+        ) {
+            $data = ['client_id' => $clientId, 'client_secret' => $clientSecret, 'grant_type' => 'client_credentials'];
+            return new Request(
+                'POST',
+                $authUrl,
+                ['Content-Type' => 'application/x-www-form-urlencoded'],
+                Http::buildQueryString($data)
+            );
+        };
+
+        return new self($getTokenRequestFunc);
+    }
+
     /**
      * Extracts an access token from the given API response
      *

tests/AuthenticationTest.php

@@ -166,6 +166,34 @@ public function getTokenRequestClientCredentialsCustomTokenResource()
         );
         $this->assertSame(['Content-Type' => ['application/x-www-form-urlencoded']], $request->getHeaders());
     }
+
+    /**
+     * @test
+     * @covers ::createApiGatewayClientCredentials
+     */
+    public function createApiGatewayClientCredentials()
+    {
+        $auth = Authentication::createApiGatewayClientCredentials('not under test', 'not under test', 'http://auth');
+        $this->assertInstanceOf(Authentication::class, $auth);
+    }
+
+    /**
+     * @test
+     * @covers ::createApiGatewayClientCredentials
+     * @covers ::getTokenRequest
+     */
+    public function getTokenRequestApiGatewayClientCredentials()
+    {
+        $auth = Authentication::createApiGatewayClientCredentials('id', 'secret', 'example.com/token');
+        $request = $auth->getTokenRequest('baseUrl');
+        $this->assertSame('example.com/token', (string)$request->getUri());
+        $this->assertSame('POST', $request->getMethod());
+        $this->assertSame(
+            'client_id=id&client_secret=secret&grant_type=client_credentials',
+            (string)$request->getBody()
+        );
+        $this->assertSame(['Content-Type' => ['application/x-www-form-urlencoded']], $request->getHeaders());
+    }
 }
 
 function time()