Merge pull request #1 from php-middleware/feature/override-policy

Override policy

Author: snapshotpl

README.md

@@ -34,7 +34,7 @@ $app->run($request, $response);
 All middleware constructor options:
 
 * `PhpMiddleware\RequestId\Generator\GeneratorInterface` `$generator` - generator implementation (required)
-* `bool` `$allowOverride` (default `true`) - if `true` and request id header exists in incoming request, then value from request header will be used in middleware, using generator will be avoid
+* `bool|PhpMiddleware\RequestId\OverridePolicy\OverridePolicyInterface` `$allowOverride` (default `true`) - if `true` and request id header exists in incoming request, then value from request header will be used in middleware, using generator will be avoid
 * `string` `$responseHeader` (default `X-Request-Id`) - request id will be added to response as header with given name. If it's not string request id will be not added to response
 * `string` `$requestHeader` (default `X-Request-Id`) - request header name
 
@@ -43,6 +43,10 @@ How to get request id in my application?
 * Middleware implements `RequestIdProviderInterface`, so you are able to use `getRequestId()` method,
 * from `request-id` attribute in `ServerRequest` object (`$request->getAttribute(RequestIdMiddleware::ATTRIBUTE_NAME)`).
 
+### Override policy
+
+You can add your own logic to decide when override incoming request id. You can implement `OverridePolicyInterface` and pass it as `$allowOverride` variable in constructor.
+
 ### Monolog processor
 
 We provide simple [Monolog](https://github.com/Seldaek/monolog) [processor](src/MonologProcessor.php) to add request it to every log entry!

src/OverridePolicy/OverridePolicyInterface.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace PhpMiddleware\RequestId\OverridePolicy;
+
+use Psr\Http\Message\ServerRequestInterface;
+
+interface OverridePolicyInterface
+{
+    public function isAllowToOverride(ServerRequestInterface $request);
+}

src/RequestIdMiddleware.php

@@ -2,7 +2,11 @@
 
 namespace PhpMiddleware\RequestId;
 
+use PhpMiddleware\RequestId\Exception\InvalidRequestId;
+use PhpMiddleware\RequestId\Exception\MissingRequestId;
+use PhpMiddleware\RequestId\Exception\NotGenerated;
 use PhpMiddleware\RequestId\Generator\GeneratorInterface;
+use PhpMiddleware\RequestId\OverridePolicy\OverridePolicyInterface;
 use PhpMiddleware\RequestId\RequestIdProviderInterface;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
@@ -18,7 +22,7 @@ class RequestIdMiddleware implements RequestIdProviderInterface
     protected $generator;
 
     /**
-     * @var bool
+     * @var bool|OverridePolicyInterface
      */
     protected $allowOverride;
 
@@ -40,7 +44,7 @@ class RequestIdMiddleware implements RequestIdProviderInterface
 
     /**
      * @param GeneratorInterface $generator
-     * @param bool $allowOverride
+     * @param bool|OverridePolicyInterface $allowOverride
      * @param string $responseHeader
      * @param string $requestHeader
      */
@@ -79,12 +83,12 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
     /**
      * @return mixed
      *
-     * @throws Exception\NotGenerated
+     * @throws NotGenerated
      */
     public function getRequestId()
     {
         if ($this->requestId === null) {
-            throw new Exception\NotGenerated('Request id is not generated yet');
+            throw new NotGenerated('Request id is not generated yet');
         }
         return $this->requestId;
     }
@@ -94,25 +98,25 @@ public function getRequestId()
      *
      * @return mixed
      *
-     * @throws Exception\MissingRequestId
-     * @throws Exception\NotGenerated
+     * @throws MissingRequestId
+     * @throws NotGenerated
      */
     protected function getRequestIdFromRequest(ServerRequestInterface $request)
     {
         if ($this->isPossibleToGetFromRequest($request)) {
             $requestId = $request->getHeaderLine($this->requestHeader);
 
             if (empty($requestId)) {
-                throw new Exception\MissingRequestId(sprintf('Missing request id in "%s" request header', $this->requestHeader));
+                throw new MissingRequestId(sprintf('Missing request id in "%s" request header', $this->requestHeader));
             }
         } else {
             $requestId = $this->generator->generateRequestId();
 
             if (empty($requestId)) {
-                throw new Exception\InvalidRequestId('Generator return empty value');
+                throw new InvalidRequestId('Generator return empty value');
             }
             if (!is_string($requestId)) {
-                throw new Exception\InvalidRequestId('Request id is not a string');
+                throw new InvalidRequestId('Request id is not a string');
             }
         }
         return $requestId;
@@ -125,6 +129,12 @@ protected function getRequestIdFromRequest(ServerRequestInterface $request)
      */
     protected function isPossibleToGetFromRequest(ServerRequestInterface $request)
     {
-        return $this->allowOverride === true && $request->hasHeader($this->requestHeader);
+        if ($this->allowOverride instanceof OverridePolicyInterface) {
+            $allowOverride = $this->allowOverride->isAllowToOverride($request);
+        } else {
+            $allowOverride = $this->allowOverride;
+        }
+
+        return $allowOverride === true && $request->hasHeader($this->requestHeader);
     }
 }

test/RequestIdMiddlewareTest.php

@@ -2,13 +2,17 @@
 
 namespace PhpMiddlewareTestTest\RequestId;
 
+use PhpMiddleware\RequestId\Exception\InvalidRequestId;
+use PhpMiddleware\RequestId\Exception\MissingRequestId;
 use PhpMiddleware\RequestId\Generator\GeneratorInterface;
+use PhpMiddleware\RequestId\OverridePolicy\OverridePolicyInterface;
 use PhpMiddleware\RequestId\RequestIdMiddleware;
+use PHPUnit_Framework_TestCase;
 use Psr\Http\Message\ServerRequestInterface;
 use Zend\Diactoros\Response;
 use Zend\Diactoros\ServerRequest;
 
-class RequestIdMiddlewareTest extends \PHPUnit_Framework_TestCase
+class RequestIdMiddlewareTest extends PHPUnit_Framework_TestCase
 {
     protected $generator;
 
@@ -67,21 +71,21 @@ public function testGenerateIdAndNotEmmitToResponse()
         $this->assertSame('123456789', $middleware->getRequestId());
     }
 
-    /**
-     * @expectedException PhpMiddleware\RequestId\Exception\MissingRequestId
-     */
     public function testTryToGetRequestIdBeforeRunMiddleware()
     {
+        $this->setExpectedException(MissingRequestId::class);
+
         $middleware = new RequestIdMiddleware($this->generator);
         $middleware->getRequestId();
     }
 
     /**
      * @dataProvider dataproviderEmptyRequestIdValues
-     * @expectedException PhpMiddleware\RequestId\Exception\InvalidRequestId
      */
     public function testTryToGenerateEmptyRequestId($emptyValue)
     {
+        $this->setExpectedException(InvalidRequestId::class);
+
         $this->generator->expects($this->once())->method('generateRequestId')->willReturn($emptyValue);
 
         $middleware = new RequestIdMiddleware($this->generator);
@@ -101,11 +105,10 @@ public function dataproviderEmptyRequestIdValues()
         ];
     }
 
-    /**
-     * @expectedException PhpMiddleware\RequestId\Exception\InvalidRequestId
-     */
     public function testTryToGenerateNotStringRequestId()
     {
+        $this->setExpectedException(InvalidRequestId::class);
+
         $this->generator->expects($this->once())->method('generateRequestId')->willReturn(1);
 
         $middleware = new RequestIdMiddleware($this->generator);
@@ -165,11 +168,9 @@ public function testDontGenerateBecouseHeaderExists()
         $this->assertSame('987654321', $middleware->getRequestId());
     }
 
-    /**
-     * @expectedException PhpMiddleware\RequestId\Exception\MissingRequestId
-     */
     public function testDontGenerateBecouseHeaderExistsButEmpty()
     {
+        $this->setExpectedException(MissingRequestId::class);
         $this->generator->expects($this->never())->method('generateRequestId');
 
         $middleware = new RequestIdMiddleware($this->generator);
@@ -178,4 +179,40 @@ public function testDontGenerateBecouseHeaderExistsButEmpty()
 
         call_user_func($middleware, $request, $response, function(){});
     }
+
+    public function testOverridePolicyAllowOverride()
+    {
+        $this->generator->method('generateRequestId')->willReturn('123456789');
+
+        $request = new ServerRequest([], [], 'https://github.com/php-middleware/request-id', 'GET', 'php://input', [RequestIdMiddleware::DEFAULT_HEADER_REQUEST_ID => '987654321']);
+
+        $policy = $this->getMock(OverridePolicyInterface::class);
+        $policy->method('isAllowToOverride')->with($request)->willReturn(true);
+        $response = new Response();
+
+        $middleware = new RequestIdMiddleware($this->generator, $policy);
+        $result = call_user_func($middleware, $request, $response, function ($request, $response) {
+            return $response;
+        });
+
+        $this->assertSame('987654321', $result->getHeaderLine(RequestIdMiddleware::DEFAULT_HEADER_REQUEST_ID));
+    }
+
+    public function testOverridePolicyDisallowOverride()
+    {
+        $this->generator->method('generateRequestId')->willReturn('123456789');
+
+        $request = new ServerRequest([], [], 'https://github.com/php-middleware/request-id', 'GET', 'php://input', [RequestIdMiddleware::DEFAULT_HEADER_REQUEST_ID => '987654321']);
+
+        $policy = $this->getMock(OverridePolicyInterface::class);
+        $policy->method('isAllowToOverride')->with($request)->willReturn(false);
+        $response = new Response();
+
+        $middleware = new RequestIdMiddleware($this->generator, $policy);
+        $result = call_user_func($middleware, $request, $response, function ($request, $response) {
+            return $response;
+        });
+
+        $this->assertSame('123456789', $result->getHeaderLine(RequestIdMiddleware::DEFAULT_HEADER_REQUEST_ID));
+    }
 }