Fix Gradle 9 compatibility issues

- Replace deprecated org.gradle.util.VersionNumber with custom version parsing
  in XbuildResolver.groovy (VersionNumber was removed in Gradle 7+)
- Update to gradle-dotnet-plugin 3.1.0 (compatible with Gradle 9)
- Replace custom Exec tasks with gradle-dotnet-plugin for better integration
- Fix generateZip task to handle cases where dotnet project properties aren't available
- Add JUnit Platform launcher dependency for Gradle 9+ compatibility
- Configure dotnet plugin with correct workingDir and solution path

Author: gamma

build.gradle

@@ -3,7 +3,7 @@ plugins {
     id 'com.gradle.plugin-publish' version '1.2.1' // Updated for Gradle 9 compatibility
     id 'signing' // Required for Maven Central
     id 'io.github.gradle-nexus.publish-plugin' version '2.0.0' // Automates Sonatype Nexus publishing
-    id 'com.itiviti.dotnet' version '2.0.1' // MSBuild-specific: for ProjectFileParser build
+    id 'com.itiviti.dotnet' version '3.1.0' // MSBuild-specific: for ProjectFileParser build (updated for Gradle 9)
     id 'de.undercouch.download' version '4.1.2' // MSBuild-specific: for vswhere.exe download
     // id 'net.researchgate.release' version '2.6.0' // Temporarily disabled for Gradle 9 compatibility
 }
@@ -44,22 +44,43 @@ dependencies {
     // JUnit 5 for JUnit Platform tests (if any)
     testImplementation(platform('org.junit:junit-bom:5.10.1'))
     testImplementation('org.junit.jupiter:junit-jupiter')
+    testRuntimeOnly('org.junit.platform:junit-platform-launcher') // Required for Gradle 9+
 }
 
 test {
     useJUnitPlatform()
 }
 
+// MSBuild-specific: .NET project build configuration using gradle-dotnet-plugin
 dotnet {
+    workingDir = projectDir // Solution is at project root
     solution = 'ProjectFileParser.sln'
-    projectName = 'ProjectFileParser'
+    configuration = 'Release'
+    restore {
+        beforeBuild = true // Delay restore until build to avoid evaluation phase issues
+    }
 }
 
 tasks.test.dependsOn(tasks.named('dotnetTest'))
 
 tasks.register('generateZip', Zip) {
-    dependsOn tasks.named('dotnetBuild')
-    from { dotnet.mainProject.properties.TargetDir } {
+    description = 'Package .NET build output into zip'
+    dependsOn 'dotnetBuild'
+    // Use the dotnet plugin's mainProject properties if available, otherwise use default location
+    from { 
+        try {
+            def mainProject = project.dotnet?.mainProject
+            if (mainProject?.properties?.TargetDir != null) {
+                file(mainProject.properties.TargetDir)
+            } else {
+                // Fallback to default output location based on solution structure
+                file("src/main/dotnet/ProjectFileParser/bin/Release/net6.0")
+            }
+        } catch (Exception e) {
+            // If dotnet project properties aren't available, use default location
+            file("src/main/dotnet/ProjectFileParser/bin/Release/net6.0")
+        }
+    } {
         include '*.exe'
         include '*.json'
         include '*.dll'

src/main/groovy/com/ullink/XbuildResolver.groovy

@@ -1,7 +1,6 @@
 package com.ullink
 
 import org.gradle.api.GradleException
-import org.gradle.util.VersionNumber
 
 class XbuildResolver implements IExecutableResolver {
 
@@ -55,7 +54,7 @@ class XbuildResolver implements IExecutableResolver {
         ]}
         .findAll { it[0].exists() }
 
-        def foundXBuild = existingXBuilds.find { msbuild.version == null || msbuild.version.equals("${it[1].major}.${it[1].minor}".toString()) }
+        def foundXBuild = existingXBuilds.find { msbuild.version == null || msbuild.version.equals("${it[1][0]}.${it[1][1]}".toString()) }
         if (foundXBuild != null) {
             File file = foundXBuild[0]
             msbuild.logger.info("Resolved xbuild to: ${file.absolutePath}")
@@ -77,9 +76,37 @@ class XbuildResolver implements IExecutableResolver {
         }
         return file.listFiles()
                 .findAll { it.isDirectory() }
-                .collect { [it.absolutePath, VersionNumber.parse(it.name)] }
-                .findAll { !VersionNumber.UNKNOWN.equals(it[1]) }
-                .sort { a, b -> b[1].compareTo(a[1]) }
+                .collect { [it.absolutePath, parseVersion(it.name)] }
+                .findAll { it[1] != null }
+                .sort { a, b -> compareVersions(b[1], a[1]) }
+    }
+
+    // Simple version parsing to replace org.gradle.util.VersionNumber (removed in Gradle 7+)
+    private static List<Integer> parseVersion(String versionString) {
+        try {
+            def parts = versionString.split('\\.')
+            def major = parts.length > 0 ? Integer.parseInt(parts[0]) : 0
+            def minor = parts.length > 1 ? Integer.parseInt(parts[1]) : 0
+            def micro = parts.length > 2 ? Integer.parseInt(parts[2]) : 0
+            return [major, minor, micro]
+        } catch (NumberFormatException e) {
+            return null // Invalid version string
+        }
+    }
+
+    // Compare two version arrays [major, minor, micro]
+    private static int compareVersions(List<Integer> v1, List<Integer> v2) {
+        if (v1 == null && v2 == null) return 0
+        if (v1 == null) return -1
+        if (v2 == null) return 1
+        
+        for (int i = 0; i < Math.max(v1.size(), v2.size()); i++) {
+            def part1 = i < v1.size() ? v1[i] : 0
+            def part2 = i < v2.size() ? v2[i] : 0
+            def cmp = part1 <=> part2
+            if (cmp != 0) return cmp
+        }
+        return 0
     }