Upgrade Gradle and add iOS targets (#27)

- Upgraded Gradle wrapper to version 8.5.
- Updated Gradle build scripts and configurations.
- Added iOS targets (iosX64, iosArm64, iosSimulatorArm64) to the Kotlin Multiplatform setup.
- Configured shared iOS source sets.
- Bumped project version to 3.1.0.
- Updated JDK version to 21 in project settings.
- Removed kotlinScripting.xml.
- Added runConfigurations.xml and AndroidProjectSystem.xml.

(cherry picked from commit 06dc507590)

.idea/AndroidProjectSystem.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="AndroidProjectSystem">
+    <option name="providerId" value="com.android.tools.idea.GradleProjectSystem" />
+  </component>
+</project>

.idea/gradle.xml

@@ -4,8 +4,9 @@
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
-        <option name="distributionType" value="WRAPPED" />
+        <option name="testRunner" value="CHOOSE_PER_TEST" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
+        <option name="gradleJvm" value="#GRADLE_LOCAL_JAVA_HOME" />
         <option name="modules">
           <set>
             <option value="$PROJECT_DIR$" />

.idea/kotlinScripting.xml

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="KotlinScriptingSettings">
-    <scriptDefinition className="org.jetbrains.kotlin.scripting.resolve.KotlinScriptDefinitionFromAnnotatedTemplate" definitionName="KotlinBuildScript">
-      <order>2147483647</order>
-      <autoReloadConfigurations>true</autoReloadConfigurations>
-    </scriptDefinition>
-  </component>
-</project>

.idea/misc.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="11" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="jbr-21" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

.idea/runConfigurations.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RunConfigurationProducerService">
+    <option name="ignoredProducers">
+      <set>
+        <option value="com.intellij.execution.junit.AbstractAllInDirectoryConfigurationProducer" />
+        <option value="com.intellij.execution.junit.AllInPackageConfigurationProducer" />
+        <option value="com.intellij.execution.junit.PatternConfigurationProducer" />
+        <option value="com.intellij.execution.junit.TestInClassConfigurationProducer" />
+        <option value="com.intellij.execution.junit.UniqueIdConfigurationProducer" />
+        <option value="com.intellij.execution.junit.testDiscovery.JUnitTestDiscoveryConfigurationProducer" />
+        <option value="org.jetbrains.kotlin.idea.junit.KotlinJUnitRunConfigurationProducer" />
+        <option value="org.jetbrains.kotlin.idea.junit.KotlinPatternConfigurationProducer" />
+      </set>
+    </option>
+  </component>
+</project>

build.gradle.kts

@@ -9,7 +9,7 @@ plugins {
 
 val PUBLISH_GROUP_ID = "com.github.adriankuta"
 val PUBLISH_ARTIFACT_ID = "tree-structure"
-val PUBLISH_VERSION = "3.0.2"
+val PUBLISH_VERSION = "3.1.0"
 
 val secretFile = File(rootProject.rootDir, "local.properties")
 if (secretFile.exists()) {
@@ -118,6 +118,12 @@ kotlin {
             }
         }
     }
+
+    // Add iOS targets
+    iosX64()
+    iosArm64()
+    iosSimulatorArm64()
+
     val hostOs = System.getProperty("os.name")
     val isMingwX64 = hostOs.startsWith("Windows")
     val nativeTarget = when {
@@ -127,7 +133,6 @@ kotlin {
         else -> throw GradleException("Host OS is not supported in Kotlin/Native.")
     }
 
-
     sourceSets {
         val commonMain by getting
         val commonTest by getting {
@@ -145,5 +150,19 @@ kotlin {
         val jsTest by getting
         val nativeMain by getting
         val nativeTest by getting
+
+        // Shared iOS source sets
+        val iosMain by creating {
+            dependsOn(commonMain)
+        }
+        val iosTest by creating {
+            dependsOn(commonTest)
+        }
+        val iosX64Main by getting { dependsOn(iosMain) }
+        val iosArm64Main by getting { dependsOn(iosMain) }
+        val iosSimulatorArm64Main by getting { dependsOn(iosMain) }
+        val iosX64Test by getting { dependsOn(iosTest) }
+        val iosArm64Test by getting { dependsOn(iosTest) }
+        val iosSimulatorArm64Test by getting { dependsOn(iosTest) }
     }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -55,7 +55,7 @@
 #       Darwin, MinGW, and NonStop.
 #
 #   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
 #       within the Gradle project.
 #
 #       You can find Gradle at https://github.com/gradle/gradle/.
@@ -80,13 +80,11 @@ do
     esac
 done
 
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
-
-APP_NAME="Gradle"
+# This is normally unused
+# shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -133,22 +131,29 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
 if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
     case $MAX_FD in  #(
       '' | soft) :;; #(
       *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -193,11 +198,15 @@ if "$cygwin" || "$msys" ; then
     done
 fi
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
@@ -205,6 +214,12 @@ set -- \
         org.gradle.wrapper.GradleWrapperMain \
         "$@"
 
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
 # Use "xargs" to parse quoted args.
 #
 # With -n1 it outputs one arg per line, with the quotes and backslashes removed.

gradlew.bat

@@ -14,7 +14,7 @@
 @rem limitations under the License.
 @rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +25,8 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,7 +41,7 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
 echo.
 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
@@ -75,13 +76,15 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 0 goto mainEnd
 
 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal