Simplify resolver to remove some special casing no longer needed

gradle-versions-plugin/src/main/kotlin/com/github/benmanes/gradle/versions/updates/Resolver.kt

@@ -89,12 +89,8 @@ class Resolver(
     revision: String,
     currentCoordinates: Map<Coordinate.Key, Coordinate>,
   ): Configuration {
-    // Kotlin deps anywhere in the hierarchy are a special case we'll handle later separately, unless they are being
-    // forced, as is the case with plugins, in which case handle those deps here
-    val kotlinDeps = { dependency: ExternalDependency -> (dependency.group?.startsWith("org.jetbrains.kotlin") ?: false) && dependency.version != null }
     val latest = configuration.allDependencies
       .filterIsInstance<ExternalDependency>()
-      .filterNot { kotlinDeps(it) && it.isForce }
       .mapTo(mutableListOf()) { dependency ->
         createQueryDependency(dependency as ModuleDependency)
       }
@@ -123,11 +119,12 @@ class Resolver(
     }
 
     // Resolve using the latest version of explicitly declared dependencies and retains Kotlin's
-    // inherited stdlib dependencies from the super configurations. This is required for variant
-    // resolution, but the full set can break consumer capability matching.
+    // inherited dependencies (importantly, including stdlib) from the super configurations. This
+    // is required for variant resolution, but the full set can break consumer capability matching.
+    val isKotlinDep = { dependency: ExternalDependency -> (dependency.group?.startsWith("org.jetbrains.kotlin") ?: false) }
     val inheritedKotlin = configuration.allDependencies
       .filterIsInstance<ExternalDependency>()
-      .filter(kotlinDeps)
+      .filter { d -> isKotlinDep(d) }
       .minus(configuration.dependencies)
 
     // Adds the Kotlin 1.2.x legacy metadata to assist in variant selection

gradle-versions-plugin/src/test/groovy/com/github/benmanes/gradle/versions/PluginUpdateDetectionSpec.groovy → gradle-versions-plugin/src/test/groovy/com/github/benmanes/gradle/versions/KotlinDependencyUpdatesSpec.groovy

@@ -8,8 +8,10 @@ import spock.lang.Specification
 
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-final class PluginUpdateDetectionSpec extends Specification {
-  private static final KOTLIN_VERSION = '1.6.0'
+final class KotlinDependencyUpdatesSpec extends Specification {
+  private static final DECLARED_KOTLIN_VERSION = '1.7.0'
+  private static final DECLARED_KOTLIN_STD_VERSION = '1.8.0'
+  private static final CURRENT_KOTLIN_VERSION = '2.0.0-Beta3'
 
   @Rule
   final TemporaryFolder testProjectDir = new TemporaryFolder()
@@ -45,7 +47,7 @@ final class PluginUpdateDetectionSpec extends Specification {
         }
       """.stripIndent()
 
-    testProjectDir.newFile('gradle.properties') << "kotlin_version = $KOTLIN_VERSION"
+    testProjectDir.newFile('gradle.properties') << "kotlin_version = $DECLARED_KOTLIN_VERSION"
 
     when:
     def result = GradleRunner.create()
@@ -56,7 +58,7 @@ final class PluginUpdateDetectionSpec extends Specification {
 
     then:
     result.output.contains """The following dependencies have later milestone versions:
- - org.jetbrains.kotlin:kotlin-gradle-plugin [$KOTLIN_VERSION -> """
+ - org.jetbrains.kotlin:kotlin-gradle-plugin [$DECLARED_KOTLIN_VERSION -> $CURRENT_KOTLIN_VERSION]"""
     result.task(':dependencyUpdates').outcome == SUCCESS
 
     where:
@@ -83,7 +85,7 @@ final class PluginUpdateDetectionSpec extends Specification {
         }
       """.stripIndent()
 
-    testProjectDir.newFile('gradle.properties') << "kotlin_version = $KOTLIN_VERSION"
+    testProjectDir.newFile('gradle.properties') << "kotlin_version = $DECLARED_KOTLIN_VERSION"
 
     when:
     def result = GradleRunner.create()
@@ -94,7 +96,47 @@ final class PluginUpdateDetectionSpec extends Specification {
 
     then:
     result.output.contains """The following dependencies have later milestone versions:
- - org.jetbrains.kotlin:kotlin-gradle-plugin [$KOTLIN_VERSION -> """
+ - org.jetbrains.kotlin:kotlin-gradle-plugin [$DECLARED_KOTLIN_VERSION -> $CURRENT_KOTLIN_VERSION]"""
     result.task(':dependencyUpdates').outcome == SUCCESS
   }
+
+  @See("https://github.com/ben-manes/gradle-versions-plugin/issues/423")
+  def "kotlin stdlib is properly handled (when added explicitly: #explicitStdLibVersion)"() {
+    given:
+    testProjectDir.newFile('build.gradle') <<
+      """
+        plugins {
+            id 'com.github.ben-manes.versions' version '0.46.0'
+            id 'org.jetbrains.kotlin.jvm' version '$DECLARED_KOTLIN_VERSION'
+        }
+
+        repositories {
+            mavenCentral()
+        }
+
+        dependencies {
+            implementation "org.jetbrains.kotlin:kotlin-stdlib${explicitStdLibVersion ? ":$DECLARED_KOTLIN_STD_VERSION" : ""}"
+        }
+      """.stripIndent()
+
+    when:
+    def result = GradleRunner.create()
+      .withProjectDir(testProjectDir.root)
+      .withArguments('dependencyUpdates', '--info')
+      .withPluginClasspath()
+      .build()
+
+    then:
+    result.output.contains """The following dependencies have later milestone versions:
+ - org.jetbrains.kotlin:kotlin-scripting-compiler-embeddable [$DECLARED_KOTLIN_VERSION -> $CURRENT_KOTLIN_VERSION]
+     https://kotlinlang.org/
+ - org.jetbrains.kotlin:kotlin-stdlib [${explicitStdLibVersion ? DECLARED_KOTLIN_STD_VERSION : DECLARED_KOTLIN_VERSION} -> $CURRENT_KOTLIN_VERSION]
+     https://kotlinlang.org/
+ - org.jetbrains.kotlin.jvm:org.jetbrains.kotlin.jvm.gradle.plugin [$DECLARED_KOTLIN_VERSION -> $CURRENT_KOTLIN_VERSION]
+     https://kotlinlang.org/"""
+    result.task(':dependencyUpdates').outcome == SUCCESS
+
+    where:
+    explicitStdLibVersion << [true, false]
+  }
 }