sdk-trace: add StatusData

sdk/trace/src/main/scala/org/typelevel/otel4s/sdk/trace/data/StatusData.scala

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2023 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 org.typelevel.otel4s.sdk.trace.data
+
+import cats.Hash
+import cats.Show
+import cats.syntax.show._
+import org.typelevel.otel4s.trace.Status
+
+/** Defines the status of a span by providing a standard status in conjunction
+  * with an optional description message.
+  *
+  * @see
+  *   [[https://opentelemetry.io/docs/specs/otel/trace/api/#set-status]]
+  */
+sealed trait StatusData {
+
+  /** The status code.
+    */
+  def status: Status
+
+  /** The description of this status for human consumption.
+    */
+  def description: Option[String]
+
+  override final def hashCode(): Int =
+    Hash[StatusData].hash(this)
+
+  override final def equals(obj: Any): Boolean =
+    obj match {
+      case other: StatusData => Hash[StatusData].eqv(this, other)
+      case _                 => false
+    }
+
+  override final def toString: String =
+    Show[StatusData].show(this)
+}
+
+object StatusData {
+
+  /** Indicates the successfully completed operation, validated by an
+    * application developer or operator.
+    */
+  val Ok: StatusData = StatusDataImpl(Status.Ok, None)
+
+  /** The default state.
+    */
+  val Unset: StatusData = StatusDataImpl(Status.Unset, None)
+
+  /** Indicates an occurred error.
+    */
+  val Error: StatusData = StatusDataImpl(Status.Error, None)
+
+  /** Returns [[StatusData]] for the given `status`.
+    */
+  def apply(status: Status): StatusData =
+    status match {
+      case Status.Ok    => Ok
+      case Status.Unset => Unset
+      case Status.Error => Error
+    }
+
+  /** Creates [[StatusData]] using the given `status` and `description`.
+    *
+    * @param status
+    *   the status of the [[StatusData]]
+    *
+    * @param description
+    *   the description of the [[StatusData]]
+    */
+  def apply(status: Status, description: String): StatusData =
+    if (description.isEmpty) apply(status)
+    else StatusDataImpl(status, Some(description))
+
+  implicit val statusDataHash: Hash[StatusData] =
+    Hash.by(a => (a.status, a.description))
+
+  implicit val statusDataShow: Show[StatusData] = Show.show { data =>
+    show"StatusData{status=${data.status}, description=${data.description}}"
+  }
+
+  private final case class StatusDataImpl(
+      status: Status,
+      description: Option[String]
+  ) extends StatusData
+
+}

sdk/trace/src/test/scala/org/typelevel/otel4s/sdk/trace/data/StatusDataSuite.scala

@@ -0,0 +1,68 @@
+package org.typelevel.otel4s.sdk.trace.data
+
+import cats.Show
+import cats.kernel.laws.discipline.HashTests
+import cats.syntax.show._
+import munit.DisciplineSuite
+import org.scalacheck.Arbitrary
+import org.scalacheck.Cogen
+import org.scalacheck.Gen
+import org.scalacheck.Prop
+import org.typelevel.otel4s.trace.Status
+
+class StatusDataSuite extends DisciplineSuite {
+
+  private val statusGen: Gen[Status] =
+    Gen.oneOf(Status.Ok, Status.Error, Status.Unset)
+
+  private val statusDataGen: Gen[StatusData] =
+    for {
+      status <- statusGen
+      description <- Gen.alphaNumStr
+    } yield StatusData(status, if (status == Status.Error) description else "")
+
+  private implicit val statusDataArbitrary: Arbitrary[StatusData] =
+    Arbitrary(statusDataGen)
+
+  private implicit val statusCogen: Cogen[Status] =
+    Cogen[String].contramap(_.toString)
+
+  private implicit val traceStateCogen: Cogen[StatusData] =
+    Cogen[(Status, Option[String])].contramap(s => (s.status, s.description))
+
+  checkAll("StatusData.HashLaws", HashTests[StatusData].hash)
+
+  test("Show[StatusData]") {
+    Prop.forAll(statusDataGen) { data =>
+      val expected =
+        show"StatusData{status=${data.status}, description=${data.description}}"
+
+      assertEquals(Show[StatusData].show(data), expected)
+    }
+  }
+
+  test("use const instances when the given description is empty") {
+    Prop.forAll(statusGen) { status =>
+      val expected = status match {
+        case Status.Ok    => StatusData.Ok
+        case Status.Error => StatusData.Error
+        case Status.Unset => StatusData.Unset
+      }
+
+      assertEquals(StatusData(status), expected)
+      assertEquals(StatusData(status, ""), expected)
+    }
+  }
+
+  test("defaults have empty description") {
+    val all = Seq(
+      StatusData.Ok,
+      StatusData.Error,
+      StatusData.Unset
+    )
+
+    all.foreach { statusData =>
+      assertEquals(statusData.description, None)
+    }
+  }
+}