Feral for AzureFunctions

azure-functions/js/src/main/scala/feral/functions/IOAzureHttpFunction.scala

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+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.functions
+
+import scala.scalajs.js
+import scala.scalajs.js.annotation._
+
+import feral.functions.facade.InvocationContext
+import feral.functions.facade.JSRequest
+import feral.functions.util.AppConfig.buildDefaultConfig
+import feral.functions.util.AppConfig
+import feral.functions.util.Parser
+
+import org.http4s.HttpApp
+
+import cats.effect.IO
+import cats.effect.Resource
+import cats.syntax.all._
+import cats.effect.unsafe.IORuntime
+import cats.effect.std.Dispatcher
+import feral.functions.facade.Context
+
+abstract class IOAzureHttpFunction {
+  protected def handler: Context => Resource[IO, HttpApp[IO]]
+  protected def appConfig: AppConfig = buildDefaultConfig(handlerFn)
+  protected def qBound: Int = 100
+
+  private[functions] val runtime = IORuntime.global
+
+  final def main(args: Array[String]): Unit =
+    IOAzureHttpFunction.App.http(functionName, appConfig.toJS)
+
+  private[functions] val functionName: String =
+    getClass.getSimpleName.init
+
+  private[functions] lazy val handlerFn
+      : js.Function2[JSRequest, InvocationContext, js.Promise[js.UndefOr[js.Any]]] = {
+    val dispatcherHandle = {
+      Dispatcher
+        .parallel[IO](await = true)
+        .product(Resource.pure(handler))
+        .allocated
+        .map(_._1) // drop unused finalizer, this resource will live for the duration
+        .unsafeToPromise()(runtime)
+    }
+
+    (requestJS, context) => {
+      dispatcherHandle.`then`[js.Any] {
+        case (dispatcher, handle) => {
+          val io = for {
+            request <- Parser.decodeRequest[IO](requestJS)
+            response <- handle(Context(context)).use(app => app.run(request))
+            respEncoded <- Parser.encodeResponse[IO](response, dispatcher, qBound)
+          } yield respEncoded
+
+          dispatcher.unsafeToPromise(io)
+        }
+      }
+    }
+  }
+}
+
+object IOAzureHttpFunction {
+  @js.native
+  @JSImport("@azure/functions", "app")
+  object App extends js.Object {
+    def http(
+        name: String,
+        appConfig: js.Object
+    ): Unit = js.native
+  }
+}

azure-functions/js/src/main/scala/feral/functions/facade/Context.scala

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+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.functions.facade
+
+final case class Context(context: InvocationContext) {
+  def log(m: String): Unit = context.log(m)
+  def trace(m: String): Unit = context.trace(m)
+  def debug(m: String): Unit = context.debug(m)
+  def info(m: String): Unit = context.info(m)
+  def warn(m: String): Unit = context.warn(m)
+  def error(m: String): Unit = context.error(m)
+}

azure-functions/js/src/main/scala/feral/functions/facade/InvocationContext.scala

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+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.functions.facade
+
+import scala.scalajs.js
+
+@js.native
+private[functions] trait InvocationContext extends js.Object {
+  def log(args: js.Any*): Unit = js.native
+  def trace(args: js.Any*): Unit = js.native
+  def debug(args: js.Any*): Unit = js.native
+  def info(args: js.Any*): Unit = js.native
+  def warn(args: js.Any*): Unit = js.native
+  def error(args: js.Any*): Unit = js.native
+
+  def functionId: String = js.native
+  def functionName: String = js.native
+  def extraInputs: ExtraInputs = js.native
+  def extraOutputs: ExtraOutputs = js.native
+  def retryContext: js.UndefOr[RetryContext] = js.native
+  def traceContext: js.UndefOr[TraceContext] = js.native
+  def options: Options = js.native
+}
+
+@js.native
+private[functions] trait ExtraInputs extends js.Object {
+  def get(binding: js.Any): js.Any = js.native
+}
+
+@js.native
+private[functions] trait ExtraOutputs extends js.Object {
+  def set(binding: js.Any, value: js.Any): Unit = js.native
+}
+
+@js.native
+private[functions] trait RetryContext extends js.Object {
+  def retryCount: Int = js.native
+  def maxRetryCount: Int = js.native
+  def exception: js.UndefOr[js.Any] = js.native
+}
+
+@js.native
+private[functions] trait TraceContext extends js.Object {
+  def traceParent: js.UndefOr[String] = js.native
+  def traceState: js.UndefOr[String] = js.native
+  def attributes: js.UndefOr[js.Dictionary[js.Any]] = js.native
+}
+
+@js.native
+private[functions] trait Options extends js.Object {
+  def trigger: js.UndefOr[js.Any] = js.native
+  def extraInputs: js.UndefOr[js.Array[js.Any]] = js.native
+  def extraOutputs: js.UndefOr[js.Array[js.Any]] = js.native
+  def `return`: js.UndefOr[js.Any] = js.native
+}

azure-functions/js/src/main/scala/feral/functions/facade/JSRequest.scala

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+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.functions.facade
+
+import scala.scalajs.js
+import scala.scalajs.js.typedarray.Uint8Array
+
+import fs2.Stream
+import fs2.Chunk
+
+import cats.effect.kernel.Async
+import cats.syntax.all._
+
+@js.native
+private[functions] trait JSRequest extends js.Object {
+  def method: String = js.native
+  def url: String = js.native
+  def headers: JSHeaders = js.native
+  def body: js.UndefOr[JSReadableStream] = js.native
+}
+
+@js.native
+private[functions] trait JSHeaders extends js.Object {
+  def get(name: String): js.UndefOr[String] = js.native
+  def keys(): js.Iterator[String] = js.native
+}
+
+@js.native
+private[functions] trait JSReadableStream extends js.Object {
+  def getReader(): JSReadableStreamDefaultReader = js.native
+}
+
+@js.native
+private[functions] trait JSReadableStreamDefaultReader extends js.Object {
+  def read(): js.Promise[JSReadObject] = js.native
+  def releaseLock(): Unit = js.native
+  def cancel(reason: js.UndefOr[js.Any]): js.Promise[Unit]
+}
+
+@js.native
+private[functions] trait JSReadObject extends js.Object {
+  def value: js.UndefOr[Uint8Array] = js.native
+  def done: Boolean = js.native
+}
+
+object JSHeaders {
+  private[functions] def keyList(h: JSHeaders): List[String] = {
+    val builder = List.newBuilder[String]
+    val itr = h.keys()
+    var entity = itr.next()
+
+    while (!entity.done) {
+      builder.addOne(entity.value)
+      entity = itr.next()
+    }
+
+    builder.result()
+  }
+
+  object Syntax {
+    // syntax for method like calls???
+  }
+}
+
+object JSReadableStream {
+  private[functions] def toFs2[F[_]: Async](
+      streamOption: js.UndefOr[JSReadableStream]): Stream[F, Byte] = {
+    streamOption.toOption match {
+      case None => Stream.empty
+      case Some(null) => Stream.empty
+      case Some(stream) => {
+        Stream.eval(Async[F].delay(stream.getReader())).flatMap { reader =>
+          def nextChunk = {
+            Async[F].fromPromise(Async[F].delay(reader.read())).map { read =>
+              if (read.done) {
+                None
+              } else {
+                val chunk = read
+                  .value
+                  .toOption
+                  .map(arr => Chunk.array[Byte](toByteArray(arr)))
+                  .getOrElse(Chunk.empty[Byte])
+
+                Some(chunk)
+              }
+            }
+          }
+
+          Stream
+            .repeatEval(nextChunk)
+            .unNoneTerminate
+            .flatMap(Stream.chunk)
+            .onFinalize(Async[F].delay(reader.releaseLock()))
+        }
+      }
+    }
+  }
+
+  private def toByteArray(array: Uint8Array): Array[Byte] = {
+    val builder = Array.newBuilder[Byte]
+    val length = array.length
+    var index = 0
+
+    while (index != length) {
+      builder.addOne(array(index).toByte)
+      index = index + 1
+    }
+
+    builder.result()
+  }
+
+  object Syntax {}
+}

azure-functions/js/src/main/scala/feral/functions/util/AppConfig.scala

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+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.functions.util
+
+import AppConfig._
+
+import scala.scalajs.js
+
+import feral.functions.facade.JSRequest
+import feral.functions.facade.InvocationContext
+
+final case class AppConfig(
+    methods: List[HttpMethod],
+    authLevel: AuthLevel,
+    route: AzureRoute,
+    handlerFn: HandlerFnT) {
+  private[functions] def toJS: js.Object = {
+    js.Dynamic
+      .literal(
+        methods = methodsToJS(methods),
+        authLevel = authLevel.value,
+        route = route.value,
+        handler = handlerFn
+      )
+  }
+}
+
+object AppConfig {
+  sealed trait HttpMethod {
+    private[functions] def value: String = {
+      this match {
+        case Get => "GET"
+        case Post => "POST"
+        case Put => "PUT"
+        case Patch => "PATCH"
+        case Delete => "DELETE"
+      }
+    }
+  }
+  case object Get extends HttpMethod
+  case object Post extends HttpMethod
+  case object Put extends HttpMethod
+  case object Patch extends HttpMethod
+  case object Delete extends HttpMethod
+
+  private def methodsToJS(list: List[HttpMethod]): js.Array[String] = {
+    val dList = list.distinct.map(_.value)
+    js.Array(dList: _*)
+  }
+
+  case class AuthLevel(value: String)
+  val anonymous: AuthLevel = AuthLevel("anonymous")
+  // add more?
+
+  case class AzureRoute(value: String)
+  val catchAll: AzureRoute = AzureRoute("{*path}")
+  // add more?
+
+  type HandlerFnT = js.Function2[JSRequest, InvocationContext, js.Promise[js.UndefOr[js.Any]]]
+
+  private[functions] def buildDefaultConfig(handlerFn: HandlerFnT) =
+    AppConfig(List(Get, Post, Put, Patch, Delete), anonymous, catchAll, handlerFn)
+}