feat(88): Added tracing capabilities using a strategy

rcardin · Dec 30, 2024 · 7a5dfbb · 7a5dfbb
1 parent 48bc7d9
commit 7a5dfbb
Show file tree

Hide file tree

Showing 3 changed files with 65 additions and 7 deletions.
diff --git a/core/src/main/scala/in/rcard/raise4s/Raise.scala b/core/src/main/scala/in/rcard/raise4s/Raise.scala
@@ -1,7 +1,7 @@
 package in.rcard.raise4s
 
 import in.rcard.raise4s
-import in.rcard.raise4s.Strategies.RecoverWith
+import in.rcard.raise4s.Strategies.{RecoverWith, TraceWith, Traced, TracedRaise}
 
 import scala.annotation.targetName
 import scala.util.Try
@@ -1768,4 +1768,16 @@ object Raise {
     */
   inline def withDefault[Error, A](default: A)(inline block: Raise[Error] ?=> A): A =
     Raise.recover(block)(error => default)
+
+  inline def traced[Error, A](
+      inline block: Raise[Error] ?=> A
+  )(using inline tracing: TraceWith[Error]): Raise[Error] ?=> A = {
+    try {
+      given tracedRaise: Raise[Error] = new TracedRaise
+      block
+    } catch
+      case traced: Traced[Error] =>
+        tracing.trace(traced)
+        Raise.raise(traced.original)
+  }
 }
diff --git a/core/src/main/scala/in/rcard/raise4s/Strategies.scala b/core/src/main/scala/in/rcard/raise4s/Strategies.scala
@@ -61,12 +61,24 @@ object Strategies {
     * actual should be(43)
     * }}}
     *
-    * @tparam Error The type of the error to recover from
-    * @tparam A The type of the value to return if the recovery is successful
-   *           
-   * @see [[Raise.recoverable]]
+    * @tparam Error
+    *   The type of the error to recover from
+    * @tparam A
+    *   The type of the value to return if the recovery is successful
+    *
+    * @see
+    *   [[Raise.recoverable]]
     */
   trait RecoverWith[Error, A] {
     def recover(error: Error): A
   }
+
+  private[raise4s] class TracedRaise extends Raise[Any]:
+    def raise(e: Any): Nothing = throw Traced(e)
+
+  case class Traced[Error](original: Error) extends Exception
+
+  trait TraceWith[Error] {
+    def trace(traced: Traced[Error]): Unit
+  }
 }
diff --git a/core/src/test/scala/in/rcard/raise4s/StrategiesSpec.scala b/core/src/test/scala/in/rcard/raise4s/StrategiesSpec.scala
@@ -1,7 +1,7 @@
 package in.rcard.raise4s
 
-import in.rcard.raise4s.Raise.raise
-import in.rcard.raise4s.Strategies.{MapError, anyRaised}
+import in.rcard.raise4s.Raise.{raise, traced}
+import in.rcard.raise4s.Strategies.{MapError, TraceWith, anyRaised}
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
 
@@ -39,4 +39,38 @@ class StrategiesSpec extends AnyFlatSpec with Matchers {
     val result: Int | String = Raise.run(finalLambda)
     result shouldBe "Hello"
   }
+
+  "TraceWith" should "allow defining a strategy that trace the error and return it" in {
+    val queue = collection.mutable.ListBuffer.empty[String]
+    given TraceWith[String] = trace => {
+      queue += trace.original
+      trace.printStackTrace()
+    }
+
+    val lambda: Int raises String = traced {
+      raise("Oops!")
+    }
+
+    val actual: String | Int = Raise.run(lambda)
+
+    actual shouldBe "Oops!"
+    queue should contain("Oops!")
+  }
+
+  it should "return the happy path value if no error is raised" in {
+    val queue = collection.mutable.ListBuffer.empty[String]
+    given TraceWith[String] = trace => {
+      queue += trace.original
+      trace.printStackTrace()
+    }
+
+    val lambda: Int raises String = traced {
+      42
+    }
+
+    val actual: Int | String = Raise.run(lambda)
+
+    actual shouldBe 42
+    queue shouldBe empty
+  }
 }