More extensible path calculation (#86)

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## [1.8.0] - October 4th, 2021
+
+### Changed
+
+- Path calculation revamped to allow for simpler selector injection
+- Kotlin version bumped to 1.5.31
+- Ktor version bumped to 1.6.4
+
 ## [1.7.0] - August 14th, 2021
 
 ### Added

README.md

@@ -119,6 +119,33 @@ suggestions on better implementations are welcome 🤠
 Under the hood, Kompendium uses Jackson to serialize the final api spec.  However, this implementation detail 
 does not leak to the actual API, meaning that users are free to choose the serialization library of their choice.  
 
+### Route Handling
+
+> ⚠️ Warning: Custom route handling is almost definitely an indication that a new Kompendium module needs to be added.  If you have encountered a route type that is not handled, please consider opening an [issue](https://github.com/bkbnio/kompendium/issues/new)
+
+Kompendium does its best to handle all Ktor routes out of the gate.  However, in keeping with the modular approach of 
+Ktor and Kompendium, this is not always possible. 
+
+Should you need to, custom route handlers can be registered via the 
+`Kompendium.addCustomRouteHandler` function.  
+
+The method declaration is a bit gross, so lets dig in to what is happening.
+
+```kotlin
+fun <T : RouteSelector> addCustomRouteHandler(
+  selector: KClass<T>,
+  handler: PathCalculator.(Route, String) -> String
+)
+```
+
+This function takes a selector, which _must_ be an implementation of the Ktor `RouteSelector`.  The handler is a function
+that extends the Kompendium `PathCalculator`.  This is necessary because it gives you access to `PathCalculator.calculate`, 
+which you are going to want in order to calculate the rest of the route :)
+
+Its parameters are the `Route` itself, along with the "tail" of the Path (the path that has been calculated thus far).
+
+Working examples `init` blocks of the `PathCalculator` and `KompendiumAuth` object.
+
 ## Examples
 
 The full source code can be found in the `kompendium-playground` module. Here is a simple get endpoint example 

build.gradle.kts

@@ -4,7 +4,7 @@ import io.gitlab.arturbosch.detekt.extensions.DetektExtension
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
-  id("org.jetbrains.kotlin.jvm") version "1.5.0" apply false
+  id("org.jetbrains.kotlin.jvm") version "1.5.31" apply false
   id("io.gitlab.arturbosch.detekt") version "1.17.0-RC3" apply false
   id("com.adarshr.test-logger") version "3.0.0" apply false
   id("io.github.gradle-nexus.publish-plugin") version "1.1.0" apply true

gradle.properties

@@ -1,5 +1,5 @@
 # Kompendium
-project.version=1.7.0
+project.version=1.8.0
 # Kotlin
 kotlin.code.style=official
 # Gradle

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 kotlin = "1.4.32"
-ktor = "1.5.3"
+ktor = "1.6.4"
 kotlinx-serialization = "1.2.1"
 jackson-kotlin = "2.12.0"
 slf4j = "1.7.30"

kompendium-auth/src/main/kotlin/io/bkbn/kompendium/auth/AuthPathCalculator.kt

@@ -1,19 +0,0 @@
-package io.bkbn.kompendium.auth
-
-import io.ktor.auth.AuthenticationRouteSelector
-import io.ktor.routing.Route
-import io.bkbn.kompendium.path.CorePathCalculator
-import org.slf4j.LoggerFactory
-
-class AuthPathCalculator : CorePathCalculator() {
-
-  private val logger = LoggerFactory.getLogger(javaClass)
-
-  override fun handleCustomSelectors(route: Route, tail: String): String = when (route.selector) {
-    is AuthenticationRouteSelector -> {
-      logger.debug("Found authentication route selector ${route.selector}")
-      super.calculate(route.parent, tail)
-    }
-    else -> super.handleCustomSelectors(route, tail)
-  }
-}

kompendium-auth/src/main/kotlin/io/bkbn/kompendium/auth/KompendiumAuth.kt

@@ -7,11 +7,14 @@ import io.ktor.auth.jwt.jwt
 import io.ktor.auth.jwt.JWTAuthenticationProvider
 import io.bkbn.kompendium.Kompendium
 import io.bkbn.kompendium.models.oas.OpenApiSpecSchemaSecurity
+import io.ktor.auth.AuthenticationRouteSelector
 
 object KompendiumAuth {
 
   init {
-      Kompendium.pathCalculator = AuthPathCalculator()
+    Kompendium.addCustomRouteHandler(AuthenticationRouteSelector::class) { route, tail ->
+      calculate(route.parent, tail)
+    }
   }
 
   fun Authentication.Configuration.notarizedBasic(

kompendium-core/src/main/kotlin/io/bkbn/kompendium/Kompendium.kt

@@ -5,8 +5,10 @@ import io.bkbn.kompendium.models.meta.SchemaMap
 import io.bkbn.kompendium.models.oas.OpenApiSpec
 import io.bkbn.kompendium.models.oas.OpenApiSpecInfo
 import io.bkbn.kompendium.models.oas.TypedSchema
-import io.bkbn.kompendium.path.CorePathCalculator
+import io.bkbn.kompendium.path.IPathCalculator
 import io.bkbn.kompendium.path.PathCalculator
+import io.ktor.routing.Route
+import io.ktor.routing.RouteSelector
 import kotlin.reflect.KClass
 
 /**
@@ -23,7 +25,7 @@ object Kompendium {
     paths = mutableMapOf()
   )
 
-  var pathCalculator: PathCalculator = CorePathCalculator()
+  fun calculatePath(route: Route) = PathCalculator.calculate(route)
 
   fun resetSchema() {
     openApiSpec = OpenApiSpec(
@@ -37,4 +39,12 @@ object Kompendium {
   fun addCustomTypeSchema(clazz: KClass<*>, schema: TypedSchema) {
     cache = cache.plus(clazz.simpleName!! to schema)
   }
+
+  fun <T : RouteSelector> addCustomRouteHandler(
+    selector: KClass<T>,
+    handler: IPathCalculator.(Route, String) -> String
+  ) {
+    PathCalculator.addCustomRouteHandler(selector, handler)
+  }
+
 }

kompendium-core/src/main/kotlin/io/bkbn/kompendium/Notarized.kt

@@ -36,7 +36,7 @@ object Notarized {
     noinline body: PipelineInterceptor<Unit, ApplicationCall>
   ): Route =
     KompendiumPreFlight.methodNotarizationPreFlight<TParam, Unit, TResp>() { paramType, requestType, responseType ->
-      val path = Kompendium.pathCalculator.calculate(this)
+      val path = Kompendium.calculatePath(this)
       Kompendium.openApiSpec.paths.getOrPut(path) { OpenApiSpecPathItem() }
       Kompendium.openApiSpec.paths[path]?.get = parseMethodInfo(info, paramType, requestType, responseType)
       return method(HttpMethod.Get) { handle(body) }
@@ -55,7 +55,7 @@ object Notarized {
     noinline body: PipelineInterceptor<Unit, ApplicationCall>
   ): Route =
     KompendiumPreFlight.methodNotarizationPreFlight<TParam, TReq, TResp>() { paramType, requestType, responseType ->
-      val path = Kompendium.pathCalculator.calculate(this)
+      val path = Kompendium.calculatePath(this)
       Kompendium.openApiSpec.paths.getOrPut(path) { OpenApiSpecPathItem() }
       Kompendium.openApiSpec.paths[path]?.post = parseMethodInfo(info, paramType, requestType, responseType)
       return method(HttpMethod.Post) { handle(body) }
@@ -74,7 +74,7 @@ object Notarized {
     noinline body: PipelineInterceptor<Unit, ApplicationCall>,
   ): Route =
     KompendiumPreFlight.methodNotarizationPreFlight<TParam, TReq, TResp>() { paramType, requestType, responseType ->
-      val path = Kompendium.pathCalculator.calculate(this)
+      val path = Kompendium.calculatePath(this)
       Kompendium.openApiSpec.paths.getOrPut(path) { OpenApiSpecPathItem() }
       Kompendium.openApiSpec.paths[path]?.put =
         parseMethodInfo(info, paramType, requestType, responseType)
@@ -93,7 +93,7 @@ object Notarized {
     noinline body: PipelineInterceptor<Unit, ApplicationCall>
   ): Route =
     KompendiumPreFlight.methodNotarizationPreFlight<TParam, Unit, TResp> { paramType, requestType, responseType ->
-      val path = Kompendium.pathCalculator.calculate(this)
+      val path = Kompendium.calculatePath(this)
       Kompendium.openApiSpec.paths.getOrPut(path) { OpenApiSpecPathItem() }
       Kompendium.openApiSpec.paths[path]?.delete = parseMethodInfo(info, paramType, requestType, responseType)
       return method(HttpMethod.Delete) { handle(body) }

kompendium-core/src/main/kotlin/io/bkbn/kompendium/path/CorePathCalculator.kt

@@ -1,51 +0,0 @@
-package io.bkbn.kompendium.path
-
-import io.ktor.routing.PathSegmentConstantRouteSelector
-import io.ktor.routing.PathSegmentParameterRouteSelector
-import io.ktor.routing.RootRouteSelector
-import io.ktor.routing.Route
-import io.ktor.util.InternalAPI
-import org.slf4j.LoggerFactory
-
-/**
- * Default [PathCalculator] meant to be overridden as necessary
- */
-open class CorePathCalculator : PathCalculator {
-
-  private val logger = LoggerFactory.getLogger(javaClass)
-
-  @OptIn(InternalAPI::class)
-  override fun calculate(
-    route: Route?,
-    tail: String
-  ): String = when (route) {
-    null -> tail
-    else -> when (route.selector) {
-      is RootRouteSelector -> {
-        logger.debug("Root route detected, returning path: $tail")
-        tail
-      }
-      is PathSegmentParameterRouteSelector -> {
-        logger.debug("Found segment parameter ${route.selector}, continuing to parent")
-        val newTail = "/${route.selector}$tail"
-        calculate(route.parent, newTail)
-      }
-      is PathSegmentConstantRouteSelector -> {
-        logger.debug("Found segment constant ${route.selector}, continuing to parent")
-        val newTail = "/${route.selector}$tail"
-        calculate(route.parent, newTail)
-      }
-      else -> when (route.selector.javaClass.simpleName) {
-        "TrailingSlashRouteSelector" -> {
-          logger.debug("Found trailing slash route selector")
-          val newTail = tail.ifBlank { "/" }
-          calculate(route.parent, newTail)
-        }
-        else -> handleCustomSelectors(route, tail)
-      }
-    }
-  }
-
-  override fun handleCustomSelectors(route: Route, tail: String): String = error("Unknown selector ${route.selector}")
-
-}

kompendium-core/src/main/kotlin/io/bkbn/kompendium/path/IPathCalculator.kt

@@ -0,0 +1,13 @@
+package io.bkbn.kompendium.path
+
+import io.ktor.routing.Route
+import io.ktor.routing.RouteSelector
+import kotlin.reflect.KClass
+
+interface IPathCalculator {
+  fun calculate(route: Route?, tail: String = ""): String
+  fun <T : RouteSelector> addCustomRouteHandler(
+    selector: KClass<T>,
+    handler: IPathCalculator.(Route, String) -> String
+  )
+}

kompendium-core/src/main/kotlin/io/bkbn/kompendium/path/PathCalculator.kt

@@ -1,20 +1,54 @@
 package io.bkbn.kompendium.path
 
+import io.ktor.routing.PathSegmentConstantRouteSelector
+import io.ktor.routing.PathSegmentParameterRouteSelector
+import io.ktor.routing.RootRouteSelector
 import io.ktor.routing.Route
+import io.ktor.routing.RouteSelector
+import io.ktor.routing.TrailingSlashRouteSelector
+import io.ktor.util.InternalAPI
+import kotlin.reflect.KClass
 
 /**
- * Extensible interface for calculating Ktor paths
+ * Responsible for calculating a url path from a provided [Route]
  */
-interface PathCalculator {
+@OptIn(InternalAPI::class)
+internal object PathCalculator: IPathCalculator {
 
-  /**
-   * Core route calculation method
-   */
-  fun calculate(route: Route?, tail: String = ""): String
-
-  /**
-   * Used to handle any custom selectors that may be missed by the base route calculation
-   */
-  fun handleCustomSelectors(route: Route, tail: String): String
+  private val pathHandler: RouteHandlerMap = mutableMapOf()
 
+  init {
+    addCustomRouteHandler(RootRouteSelector::class) { _, tail -> tail }
+    addCustomRouteHandler(PathSegmentParameterRouteSelector::class) { route, tail ->
+      val newTail = "/${route.selector}$tail"
+      calculate(route.parent, newTail)
+    }
+    addCustomRouteHandler(PathSegmentConstantRouteSelector::class) { route, tail ->
+      val newTail = "/${route.selector}$tail"
+      calculate(route.parent, newTail)
+    }
+    addCustomRouteHandler(TrailingSlashRouteSelector::class) { route, tail ->
+      val newTail = tail.ifBlank { "/" }
+      calculate(route.parent, newTail)
+    }
+  }
+
+  @OptIn(InternalAPI::class)
+  override fun calculate(
+    route: Route?,
+    tail: String
+  ): String = when (route) {
+    null -> tail
+    else -> when (pathHandler.containsKey(route.selector::class)) {
+      true -> pathHandler[route.selector::class]!!.invoke(this, route, tail)
+      else -> error("No handler has been registered for ${route.selector}")
+    }
+  }
+
+  override fun <T : RouteSelector> addCustomRouteHandler(
+    selector: KClass<T>,
+    handler: IPathCalculator.(Route, String) -> String
+  ) {
+    pathHandler[selector] = handler
+  }
 }

kompendium-core/src/main/kotlin/io/bkbn/kompendium/path/RouteHandlerMap.kt

@@ -0,0 +1,7 @@
+package io.bkbn.kompendium.path
+
+import io.ktor.routing.Route
+import io.ktor.routing.RouteSelector
+import kotlin.reflect.KClass
+
+typealias RouteHandlerMap = MutableMap<KClass<out RouteSelector>, IPathCalculator.(Route, String) -> String>