Update error message if plugin is applied in the wrong file

That also changes the IllegalStateException to an IllegalArgumentException

Author: LouisCAD

plugins/dependencies/src/main/kotlin/de/fayard/refreshVersions/RefreshVersionsPlugin.kt

@@ -10,6 +10,7 @@ import org.gradle.api.DefaultTask
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.initialization.Settings
+import org.gradle.api.invocation.Gradle
 import org.gradle.kotlin.dsl.*
 
 open class RefreshVersionsPlugin : Plugin<Any> {
@@ -32,15 +33,21 @@ open class RefreshVersionsPlugin : Plugin<Any> {
 
 
     override fun apply(target: Any) {
-        when (target) {
-            is Settings -> bootstrap(target)
-            is Project -> error(
-                """
-                Gradle plugins.id("de.fayard.refreshVersions") must be configured in settings.gradle(.kts), not in build.gradle(.kts)
-                See https://jmfayard.github.io/refreshVersions/setup/
-                """.trimIndent()
-            )
+        require(target is Settings) {
+            val notInExtraClause: String = when (target) {
+                is Project -> when (target) {
+                    target.rootProject -> ", not in build.gradle(.kts)"
+                    else -> ", not in a build.gradle(.kts) file."
+                }
+                is Gradle -> ", not in an initialization script."
+                else -> ""
+            }
+            """
+            plugins.id("de.fayard.refreshVersions") must be configured in settings.gradle(.kts)$notInExtraClause.
+            See https://jmfayard.github.io/refreshVersions/setup/
+            """.trimIndent()
         }
+        bootstrap(target)
     }
 
     private fun bootstrap(settings: Settings) {