Provide easier access to path parameters

Author: mduesterhoeft

src/main/kotlin/com/github/mduesterhoeft/router/RequestHandler.kt

@@ -28,7 +28,7 @@ abstract class RequestHandler : RequestHandler<APIGatewayProxyRequestEvent, APIG
             if (matchResult.match) {
                 val handler: HandlerFunction<Any, Any> = routerFunction.handler
                 val requestBody = deserializeRequest(handler, input)
-                val request = Request(input, requestBody)
+                val request = Request(input, requestBody, routerFunction.requestPredicate.pathPattern)
                 val response = router.filter.then(handler as HandlerFunction<*, *>).invoke(request)
                 return createResponse(input, response)
             }

src/main/kotlin/com/github/mduesterhoeft/router/Router.kt

@@ -85,4 +85,8 @@ data class RouterFunction<I, T>(
     val handler: HandlerFunction<I, T>
 )
 
-data class Request<I>(val apiRequest: APIGatewayProxyRequestEvent, val body: I)
+data class Request<I>(val apiRequest: APIGatewayProxyRequestEvent, val body: I, val pathPattern: String) {
+
+    val pathParameters by lazy { UriTemplate.from(pathPattern).extract(apiRequest.path) }
+    fun getPathParameter(name: String) = pathParameters[name]
+}

src/test/kotlin/com/github/mduesterhoeft/router/RequestHandlerTest.kt

@@ -188,7 +188,7 @@ class RequestHandlerTest {
                 ResponseEntity.ok(TestResponse("Hello"))
             }
             GET("/some/{id}") { r: Request<Unit> ->
-                ResponseEntity.ok(TestResponse("Hello ${UriTemplate.from("/some/{id}").extract(r.apiRequest.path)["id"]}"))
+                ResponseEntity.ok(TestResponse("Hello ${r.getPathParameter("id")}"))
             }
             GET("/some-proto") { _: Request<Unit> ->
                 ResponseEntity.ok(Sample.newBuilder().setHello("Hello").build())