fixing problem with logger.exit (#85)

* added support for same functionality as slf4j-ext.

* fixing signature of exit

Author: corneil

settings.gradle.kts

@@ -1,5 +1,7 @@
 rootProject.name = "kotlin-logging"
 
+enableFeaturePreview("GRADLE_METADATA")
+
 buildscript {
     repositories {
         mavenCentral()

src/commonMain/kotlin/mu/KLogger.kt

@@ -118,7 +118,7 @@ expect interface KLogger {
   /**
    * Add a log message with the return value of a method
    */
-  fun <T> exit(retval: T): T where T : Any
+  fun <T> exit(retval: T?): T? where T : Any
 
   /**
    * Add a log message indicating an exception will be thrown along with the stack trace.

src/jsMain/kotlin/mu/KLogger.kt

@@ -118,7 +118,7 @@ actual interface KLogger {
   /**
    * Add a log message with the return value of a method
    */
-  actual fun <T> exit(retval: T): T where T : Any
+  actual fun <T> exit(retval: T?): T? where T : Any
 
   /**
    * Add a log message indicating an exception will be thrown along with the stack trace.

src/jsMain/kotlin/mu/internal/KLoggerJS.kt

@@ -84,8 +84,8 @@ internal class KLoggerJS(
         TRACE.logIfEnabled({ "exit()" }, APPENDER::trace)
     }
 
-    override fun <T : Any> exit(retval: T): T {
-        TRACE.logIfEnabled({ "exut($retval)" }, APPENDER::trace)
+    override fun <T : Any> exit(retval: T?): T? {
+        TRACE.logIfEnabled({ "exit($retval)" }, APPENDER::trace)
         return retval
     }
 

src/jvmMain/kotlin/mu/KLogger.kt

@@ -127,7 +127,7 @@ actual interface KLogger : Logger {
   /**
    * Add a log message with the return value of a method
    */
-  actual fun <T> exit(retval: T): T where T : Any
+  actual fun <T> exit(retval: T?): T? where T : Any
 
   /**
    * Add a log message indicating an exception will be thrown along with the stack trace.

src/jvmMain/kotlin/mu/internal/LocationAwareKLogger.kt

@@ -641,10 +641,10 @@ internal class LocationAwareKLogger(override val underlyingLogger: LocationAware
         }
     }
 
-    override fun <T: Any> exit(retval: T): T  {
+    override fun <T: Any> exit(retval: T?): T?  {
         if (underlyingLogger.isTraceEnabled(EXIT)) {
             val tp = MessageFormatter.format(EXITMESSAGE, retval)
-            underlyingLogger.log(EXIT, fqcn, LocationAwareLogger.TRACE_INT, tp.message, arrayOf<Any>(retval), tp.throwable)
+            underlyingLogger.log(EXIT, fqcn, LocationAwareLogger.TRACE_INT, tp.message, arrayOf<Any?>(retval), tp.throwable)
         }
         return retval
     }

src/jvmMain/kotlin/mu/internal/LocationIgnorantKLogger.kt

@@ -164,7 +164,7 @@ internal class LocationIgnorantKLogger(override val underlyingLogger: Logger)
         }
     }
 
-    override inline fun <T : Any> exit(retval: T): T {
+    override inline fun <T : Any> exit(retval: T?): T? {
         if (underlyingLogger.isTraceEnabled) {
             underlyingLogger.trace("exit({}}", retval)
         }

src/jvmTest/resources/log4j2.xml

@@ -1,15 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<Configuration status="INFO">
+<Configuration status="TRACE">
     <Appenders>
         <!-- A1 is a ConsoleAppender, using PatternLayout. -->
         <Console name="A1" target="SYSTEM_OUT">
-            <PatternLayout pattern="%-4r [%t] %-5p %c %marker - %m%n" />
+            <PatternLayout pattern="%-4r [%t] %-5p %c %marker - %m%n"/>
         </Console>
     </Appenders>
     <Loggers>
         <!-- Set root logger level to TRACE and its only appender to A1. -->
         <Root level="TRACE">
-            <AppenderRef ref="A1" />
+            <AppenderRef ref="A1"/>
         </Root>
     </Loggers>
-</Configuration>
+</Configuration>