Merge pull request #683 from armanbilge/topic/deprecate-implicit-slf4…

…j-logger-factory Deprecate implicit materialization of `Slf4jFactory`
typelevel · Sep 20, 2022 · 5e239db · 5e239db
2 parents a4351b5 + 93aa9ba
commit 5e239db
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Showing 4 changed files with 22 additions and 29 deletions.
diff --git a/docs/index.md b/docs/index.md
@@ -100,29 +100,17 @@ This brings several advantages:
 If you are unsure how to create a new `LoggerFactory[F]` instance, then you can look at the `log4cats-slf4j`,
 or `log4cats-noop` modules for concrete implementations.
 
-The quickest fix might be to import needed implicits:
-```scala mdoc:silent
-// assumes dependency on log4cats-slf4j module
-import org.typelevel.log4cats._
-import org.typelevel.log4cats.slf4j._
-
-val logger: SelfAwareStructuredLogger[IO] = LoggerFactory[IO].getLogger
-
-// or
-def anyFSyncLogger[F[_]: Sync]: SelfAwareStructuredLogger[F] = Slf4jFactory[F].getLogger
-```
-
-Alternatively, a mutually exclusive solution is to explicitly create your 
-`LoggerFactory[F]` instance and pass them around implicitly:
+The quickest fix might be to create an instance of a `Slf4jFactory` and pass it around implicitly:
 ```scala mdoc:reset:silent
 import cats.effect.IO
 import cats.Monad
 import cats.syntax.all._
 import org.typelevel.log4cats._
+// assumes dependency on log4cats-slf4j module
 import org.typelevel.log4cats.slf4j.Slf4jFactory
 
 // create our LoggerFactory
-implicit val logging: LoggerFactory[IO] = Slf4jFactory[IO]
+implicit val logging: LoggerFactory[IO] = Slf4jFactory.create[IO]
 
 // we summon LoggerFactory instance, and create logger
 val logger: SelfAwareStructuredLogger[IO] = LoggerFactory[IO].getLogger

diff --git a/slf4j/src/main/scala/org/typelevel/log4cats/slf4j/Slf4jFactory.scala b/slf4j/src/main/scala/org/typelevel/log4cats/slf4j/Slf4jFactory.scala
@@ -17,6 +17,7 @@
 package org.typelevel.log4cats
 package slf4j
 
+import cats.effect.kernel.Sync
 import org.slf4j.{Logger => JLogger}
 
 trait Slf4jFactory[F[_]] extends LoggerFactory[F] {
@@ -28,6 +29,20 @@ trait Slf4jFactory[F[_]] extends LoggerFactory[F] {
 object Slf4jFactory extends LoggerFactoryGenCompanion {
   def apply[F[_]: Slf4jFactory]: Slf4jFactory[F] = implicitly
 
+  def create[F[_]: Sync]: Slf4jFactory[F] = new Slf4jFactory[F] {
+    override def getLoggerFromName(name: String): SelfAwareStructuredLogger[F] =
+      Slf4jLogger.getLoggerFromName(name)
+
+    override def getLoggerFromSlf4j(logger: JLogger): SelfAwareStructuredLogger[F] =
+      Slf4jLogger.getLoggerFromSlf4j(logger)
+
+    override def fromName(name: String): F[SelfAwareStructuredLogger[F]] =
+      Slf4jLogger.fromName(name)
+
+    override def fromSlf4j(logger: JLogger): F[SelfAwareStructuredLogger[F]] =
+      Slf4jLogger.fromSlf4j(logger)
+  }
+
   def getLoggerFromSlf4j[F[_]](logger: JLogger)(implicit
       lf: Slf4jFactory[F]
   ): SelfAwareStructuredLogger[F] = lf.getLoggerFromSlf4j(logger)

diff --git a/slf4j/src/main/scala/org/typelevel/log4cats/slf4j/package.scala b/slf4j/src/main/scala/org/typelevel/log4cats/slf4j/package.scala
@@ -17,20 +17,10 @@
 package org.typelevel.log4cats
 
 import cats.effect.Sync
-import org.slf4j.{Logger => JLogger}
 
 package object slf4j {
-  implicit def loggerFactoryforSync[F[_]: Sync]: Slf4jFactory[F] = new Slf4jFactory[F] {
-    override def getLoggerFromName(name: String): SelfAwareStructuredLogger[F] =
-      Slf4jLogger.getLoggerFromName(name)
 
-    override def getLoggerFromSlf4j(logger: JLogger): SelfAwareStructuredLogger[F] =
-      Slf4jLogger.getLoggerFromSlf4j(logger)
-
-    override def fromName(name: String): F[SelfAwareStructuredLogger[F]] =
-      Slf4jLogger.fromName(name)
-
-    override def fromSlf4j(logger: JLogger): F[SelfAwareStructuredLogger[F]] =
-      Slf4jLogger.fromSlf4j(logger)
-  }
+  @deprecated("Use Slf4jFactory.create[F] explicitly", "2.6.0")
+  implicit def loggerFactoryforSync[F[_]: Sync]: Slf4jFactory[F] =
+    Slf4jFactory.create[F]
 }
diff --git a/slf4j/src/test/scala/org/typelevel/log4cats/slf4j/Slf4jLoggerMacroCompilationTests.scala b/slf4j/src/test/scala/org/typelevel/log4cats/slf4j/Slf4jLoggerMacroCompilationTests.scala
@@ -48,7 +48,7 @@ class Slf4jLoggerOuterClassMacroTest {
 
 object LoggingBaseline {
   val t = new Throwable
-  def logger[F[_]: Sync]: SelfAwareStructuredLogger[F] = Slf4jFactory.getLogger[F]
+  def logger[F[_]: Sync]: SelfAwareStructuredLogger[F] = Slf4jFactory.create[F].getLogger
 
   val traceM = logger[IO].trace("")
   val traceTM = logger[IO].trace(t)("")