Close #441 - Add MdcAdapter for Cats Effect 3 to properly share context through MDC with IO and IOLocal from Cats Effect 3

Author: kevin-lee

build.sbt

@@ -84,6 +84,7 @@ lazy val loggerF = (project in file("."))
     slf4jMdcNative,
     logbackMdcMonix3Jvm,
     testLogbackMdcMonix3Jvm,
+    logbackMdcCatsEffect3Jvm,
     doobie1Jvm,
     testKitJvm,
     testKitJs,
@@ -342,6 +343,29 @@ lazy val testLogbackMdcMonix3    = testProject(ProjectName("logback-mdc-monix3")
   )
 lazy val testLogbackMdcMonix3Jvm = testLogbackMdcMonix3.jvm
 
+lazy val logbackMdcCatsEffect3    = module(ProjectName("logback-mdc-cats-effect3"), crossProject(JVMPlatform))
+  .settings(
+    description := "Logger for F[_] - logback MDC context map support for Cats Effect 3",
+    libraryDependencies ++= Seq(
+      libs.logbackClassic,
+      libs.logbackScalaInterop,
+      libs.catsEffect3Eap,
+      libs.tests.effectieCatsEffect3,
+      libs.tests.extrasHedgehogCatsEffect3,
+    ) ++ libs.tests.hedgehogLibs,
+    libraryDependencies := libraryDependenciesRemoveScala3Incompatible(
+      scalaVersion.value,
+      libraryDependencies.value,
+    ),
+    javaOptions += "-Dcats.effect.ioLocalPropagation=true",
+  )
+  .dependsOn(
+    core,
+    monix       % Test,
+    slf4jLogger % Test,
+  )
+lazy val logbackMdcCatsEffect3Jvm = logbackMdcCatsEffect3.jvm
+
 lazy val doobie1    = module(ProjectName("doobie1"), crossProject(JVMPlatform))
   .settings(
     description := "Logger for F[_] - for Doobie v1",
@@ -890,6 +914,7 @@ def projectCommonSettings(projectName: String, crossProject: CrossProject.Builde
       //      , Compile / compile / wartremoverErrors ++= commonWarts((update / scalaBinaryVersion).value)
       //      , Test / compile / wartremoverErrors ++= commonWarts((update / scalaBinaryVersion).value)
       wartremoverErrors ++= commonWarts((update / scalaBinaryVersion).value),
+      fork := true,
       Compile / console / wartremoverErrors := List.empty,
       Compile / console / wartremoverWarnings := List.empty,
       Compile / console / scalacOptions :=

changelogs/2.2.0-beta1.md

@@ -0,0 +1,4 @@
+## [2.2.0-beta1](https://github.com/Kevin-Lee/logger-f/issues?q=is%3Aissue+milestone%3Av2-m3) - 2025-01-03
+
+* Add `MdcAdapter` for Cats Effect 3 to properly share context through `MDC` with `IO` and `IOLocal` from Cats Effect 3 (#441)
+  * This is a beta released for testing the new feature with cats-effect `3.6-02a43a6`.

modules/logger-f-cats-effect3/shared/src/test/scala/loggerf/cats/testing/ConcurrentSupport.scala

@@ -25,7 +25,10 @@ trait ConcurrentSupport {
           val stringWriter = new StringWriter()
           val printWriter  = new PrintWriter(stringWriter)
           th.printStackTrace(printWriter)
-          logger(s"⚠️ Error in Executor: ${stringWriter.toString}")
+
+          @SuppressWarnings(Array("org.wartremover.warts.ToString"))
+          val message = stringWriter.toString
+          logger(s"⚠️ Error in Executor: $message")
         },
       )
 

modules/logger-f-logback-mdc-cats-effect3/shared/src/main/scala/loggerf/logger/logback/Ce3MdcAdapter.scala

@@ -0,0 +1,85 @@
+package loggerf.logger.logback
+
+import cats.effect.unsafe.IOLocals
+import cats.effect.{IOLocal, SyncIO}
+import cats.syntax.all._
+import ch.qos.logback.classic.LoggerContext
+import logback_scala_interop.JLoggerFMdcAdapter
+import org.slf4j.{LoggerFactory, MDC}
+
+import java.util.{Map => JMap, Set => JSet}
+import scala.jdk.CollectionConverters._
+import scala.util.control.NonFatal
+
+/** @author Kevin Lee
+  * @since 2023-07-07
+  */
+class Ce3MdcAdapter extends JLoggerFMdcAdapter {
+
+  private[this] val localContext: IOLocal[Map[String, String]] =
+    IOLocal[Map[String, String]](Map.empty[String, String])
+      .syncStep(1)
+      .flatMap(
+        _.leftMap(_ =>
+          new Error(
+            "Failed to initialize the local context of the Ce3MdcAdapter."
+          )
+        ).liftTo[SyncIO]
+      )
+      .unsafeRunSync()
+
+  override def put(key: String, `val`: String): Unit =
+    IOLocals.update(localContext)(_ + (key -> `val`))
+
+  @SuppressWarnings(Array("org.wartremover.warts.Null"))
+  override def get(key: String): String =
+    IOLocals.get(localContext).getOrElse(key, null) // scalafix:ok DisableSyntax.null
+
+  override def remove(key: String): Unit = IOLocals.update(localContext)(_ - key)
+
+  override def clear(): Unit = IOLocals.reset(localContext)
+
+  override def getCopyOfContextMap: JMap[String, String] = getPropertyMap0
+
+  override def setContextMap0(contextMap: JMap[String, String]): Unit =
+    IOLocals.set(localContext, contextMap.asScala.toMap)
+
+  private def getPropertyMap0: JMap[String, String] = IOLocals.get(localContext).asJava
+
+  override def getPropertyMap: JMap[String, String] = getPropertyMap0
+
+  override def getKeys: JSet[String] = IOLocals.get(localContext).keySet.asJava
+
+}
+object Ce3MdcAdapter {
+
+  @SuppressWarnings(Array("org.wartremover.warts.Null"))
+  private def initialize0(): Ce3MdcAdapter = {
+    val field   = classOf[MDC].getDeclaredField("mdcAdapter")
+    field.setAccessible(true)
+    val adapter = new Ce3MdcAdapter
+    field.set(null, adapter) // scalafix:ok DisableSyntax.null
+    field.setAccessible(false)
+    adapter
+  }
+
+  @SuppressWarnings(Array("org.wartremover.warts.AsInstanceOf", "scalafix:DisableSyntax.asInstanceOf"))
+  def initialize(): Ce3MdcAdapter = {
+    val loggerContext =
+      LoggerFactory.getILoggerFactory.asInstanceOf[LoggerContext]
+    initializeWithLoggerContext(loggerContext)
+  }
+
+  def initializeWithLoggerContext(loggerContext: LoggerContext): Ce3MdcAdapter = {
+    val adapter = initialize0()
+    try {
+      val field = classOf[LoggerContext].getDeclaredField("mdcAdapter")
+      field.setAccessible(true)
+      field.set(loggerContext, adapter)
+      field.setAccessible(false)
+      adapter
+    } catch {
+      case NonFatal(_) => adapter
+    }
+  }
+}