From 3e700be0b7df8022627b1f46890f3e3dad3fa54b Mon Sep 17 00:00:00 2001
From: Jakob Odersky <jakob@driver.xyz>
Date: Wed, 12 Jul 2017 22:26:07 -0700
Subject: Handle errors by failing futures in REST services

---
 .../xyz/driver/pdsuicommon/error/DomainError.scala |  8 ++
 .../xyz/driver/pdsuicommon/error/ErrorCode.scala   | 17 +++++
 .../driver/pdsuicommon/error/ErrorsResponse.scala  | 89 ++++++++++++++++++++++
 3 files changed, 114 insertions(+)
 create mode 100644 src/main/scala/xyz/driver/pdsuicommon/error/ErrorCode.scala
 create mode 100644 src/main/scala/xyz/driver/pdsuicommon/error/ErrorsResponse.scala

(limited to 'src/main/scala/xyz/driver/pdsuicommon/error')

diff --git a/src/main/scala/xyz/driver/pdsuicommon/error/DomainError.scala b/src/main/scala/xyz/driver/pdsuicommon/error/DomainError.scala
index 4bf90d1..fc8e474 100644
--- a/src/main/scala/xyz/driver/pdsuicommon/error/DomainError.scala
+++ b/src/main/scala/xyz/driver/pdsuicommon/error/DomainError.scala
@@ -28,3 +28,11 @@ object DomainError {
     Unsafe(Utils.getClassSimpleName(x.getClass))
   }
 }
+
+/** Subclasses of this exception correspond to subclasses of DomainError. They
+  * are used in REST service implementations to fail futures rather than
+  * returning successful futures, completed with corresponding DomainErrors. */
+class DomainException(message: String)         extends RuntimeException(message)
+class NotFoundException(message: String)       extends DomainException(message) // 404
+class AuthenticationException(message: String) extends DomainException(message) // 401
+class AuthorizationException(message: String)  extends DomainException(message) // 403
diff --git a/src/main/scala/xyz/driver/pdsuicommon/error/ErrorCode.scala b/src/main/scala/xyz/driver/pdsuicommon/error/ErrorCode.scala
new file mode 100644
index 0000000..5574c01
--- /dev/null
+++ b/src/main/scala/xyz/driver/pdsuicommon/error/ErrorCode.scala
@@ -0,0 +1,17 @@
+package xyz.driver.pdsuicommon.error
+
+import play.api.libs.functional.syntax._
+import play.api.libs.json.{Format, Reads, Writes}
+
+@SuppressWarnings(Array("org.wartremover.warts.Enumeration"))
+object ErrorCode extends Enumeration {
+
+  type ErrorCode = Value
+  val Unspecified = Value(1)
+
+  private val fromJsonReads: Reads[ErrorCode] = Reads.of[Int].map(ErrorCode.apply)
+  private val toJsonWrites: Writes[ErrorCode] = Writes.of[Int].contramap(_.id)
+
+  implicit val jsonFormat: Format[ErrorCode] = Format(fromJsonReads, toJsonWrites)
+
+}
diff --git a/src/main/scala/xyz/driver/pdsuicommon/error/ErrorsResponse.scala b/src/main/scala/xyz/driver/pdsuicommon/error/ErrorsResponse.scala
new file mode 100644
index 0000000..6ceadb2
--- /dev/null
+++ b/src/main/scala/xyz/driver/pdsuicommon/error/ErrorsResponse.scala
@@ -0,0 +1,89 @@
+package xyz.driver.pdsuicommon.error
+
+import xyz.driver.pdsuicommon.json.Serialization.seqJsonFormat
+import ErrorCode.{ErrorCode, Unspecified}
+import ErrorsResponse.ResponseError
+import xyz.driver.pdsuicommon.auth.{AnonymousRequestContext, RequestId}
+import xyz.driver.pdsuicommon.utils.Utils
+import play.api.http.Writeable
+import play.api.libs.functional.syntax._
+import play.api.libs.json._
+import play.api.mvc.{Result, Results}
+import xyz.driver.pdsuicommon.validation.JsonValidationErrors
+
+class ErrorsResponse(val errors: Seq[ResponseError], private val httpStatus: Results#Status, val requestId: RequestId) {
+  def toResult(implicit writeable: Writeable[ErrorsResponse]): Result = httpStatus(this)
+}
+
+object ErrorsResponse {
+
+  /**
+    * @param data      Any data that can be associated with particular error.Ex.: error field name
+    * @param message   Error message
+    * @param code      Unique error code
+    *
+    * @see https://driverinc.atlassian.net/wiki/display/RA/REST+API+Specification#RESTAPISpecification-HTTPStatuscodes
+    */
+  final case class ResponseError(data: Option[String], message: String, code: ErrorCode)
+
+  object ResponseError {
+
+    implicit val responseErrorJsonFormat: Format[ResponseError] = (
+      (JsPath \ "data").formatNullable[String] and
+        (JsPath \ "message").format[String] and
+        (JsPath \ "code").format[ErrorCode]
+    )(ResponseError.apply, unlift(ResponseError.unapply))
+
+  }
+
+  implicit val writes: Writes[ErrorsResponse] = Writes { errorsResponse =>
+    Json.obj(
+      "errors"    -> Json.toJson(errorsResponse.errors),
+      "requestId" -> Json.toJson(errorsResponse.requestId.value)
+    )
+  }
+
+  // deprecated, will be removed in REP-436
+  def fromString(message: String, httpStatus: Results#Status)(
+          implicit context: AnonymousRequestContext): ErrorsResponse = {
+    new ErrorsResponse(
+      errors = Seq(
+        ResponseError(
+          data = None,
+          message = message,
+          code = Unspecified
+        )),
+      httpStatus = httpStatus,
+      requestId = context.requestId
+    )
+  }
+
+  // scalastyle:off null
+  def fromExceptionMessage(e: Throwable, httpStatus: Results#Status = Results.InternalServerError)(
+          implicit context: AnonymousRequestContext): ErrorsResponse = {
+    val message = if (e.getMessage == null || e.getMessage.isEmpty) {
+      Utils.getClassSimpleName(e.getClass)
+    } else {
+      e.getMessage
+    }
+
+    fromString(message, httpStatus)
+  }
+  // scalastyle:on null
+
+  // deprecated, will be removed in REP-436
+  def fromJsonValidationErrors(validationErrors: JsonValidationErrors)(
+          implicit context: AnonymousRequestContext): ErrorsResponse = {
+    val errors = validationErrors.map {
+      case (path, xs) =>
+        ResponseError(
+          data = Some(path.toString()),
+          message = xs.map(_.message).mkString("\n"),
+          code = Unspecified
+        )
+    }
+
+    new ErrorsResponse(errors, Results.BadRequest, context.requestId)
+  }
+
+}
-- 
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