JAVA-42811 Upgrade main Kotlin version

Author: anastasiosioannidis

core-kotlin-modules/core-kotlin-6/src/test/kotlin/com/baeldung/elapsed/ElapsedTimeUnitTest.kt

@@ -10,7 +10,6 @@ import kotlin.time.ExperimentalTime
 import kotlin.time.TimedValue
 import kotlin.time.measureTime
 import kotlin.time.measureTimedValue
-import kotlin.time.milliseconds
 import kotlin.time.toDuration
 
 class ElapsedTimeUnitTest {

core-kotlin-modules/core-kotlin-advanced-4/pom.xml

@@ -55,6 +55,7 @@
 
     <properties>
         <kotlin-scripting.version>1.8.0</kotlin-scripting.version>
+        <kotlin.version>2.0.21</kotlin.version>
     </properties>
 
 </project>

core-kotlin-modules/core-kotlin-io/src/test/kotlin/com/baeldung/fileupload/FileUploadUnitTest.kt

@@ -8,6 +8,7 @@ import com.github.tomakehurst.wiremock.client.WireMock.matching
 import com.github.tomakehurst.wiremock.client.WireMock.post
 import com.github.tomakehurst.wiremock.client.WireMock.postRequestedFor
 import com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo
+import com.github.tomakehurst.wiremock.core.WireMockConfiguration
 import com.github.tomakehurst.wiremock.junit.WireMockRule
 import io.ktor.client.HttpClient
 import io.ktor.client.engine.cio.CIO
@@ -18,16 +19,12 @@ import io.ktor.client.statement.readText
 import io.ktor.http.Headers
 import io.ktor.http.HttpHeaders
 import kotlinx.coroutines.runBlocking
-import okhttp3.Call
-import okhttp3.Callback
 import okhttp3.MediaType.Companion.toMediaTypeOrNull
 import okhttp3.MultipartBody
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.asRequestBody
-import okhttp3.Response
 import okhttp3.ResponseBody
-import okhttp3.internal.wait
 import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.BeforeEach
 import org.junit.Rule
@@ -38,7 +35,6 @@ import retrofit2.http.Multipart
 import retrofit2.http.POST
 import retrofit2.http.Part
 import java.io.File
-import java.io.IOException
 
 fun uploadFileFuel(filePath: String, uploadUrl: String) {
     val file = File(filePath)
@@ -112,7 +108,7 @@ fun uploadFileRetrofit(filePath: String, uploadUrl: String) {
 class FileUploadUnitTest {
     @Rule
     @JvmField
-    val wireMockRule = WireMockRule(8080)
+    val wireMockRule = WireMockRule(WireMockConfiguration.wireMockConfig().dynamicPort())
 
     @BeforeEach
     fun startWireMock() {

core-kotlin-modules/core-kotlin-strings-4/src/test/kotlin/com/baeldung/booleanValueOfKotlinEquivalent/BooleanValueOfKotlinEquivalentUnitTest.kt

@@ -75,7 +75,7 @@ fun convertStringToBooleanUsingRegex(input: String): Boolean {
 }
 
 fun String.toBooleanValue(): Boolean =
-    when (this.toLowerCase()) {
+    when (this.lowercase()) {
         "true" -> true
         else -> false
     }

pom.xml

@@ -803,7 +803,7 @@
     </profiles>
 
     <properties>
-        <kotlin.version>2.0.21</kotlin.version>
+        <kotlin.version>2.1.0</kotlin.version>
         <kotlinx.version>1.7.1</kotlinx.version>
         <ktlint-cli.version>1.0.1</ktlint-cli.version>