[Optics] Show error for generic classes in KSP plug-in

arrow-libs/optics/arrow-optics-ksp-plugin/build.gradle.kts

@@ -1,5 +1,5 @@
 plugins {
-  id(libs.plugins.kotlin.jvm.get().pluginId)
+  id(libs.plugins.kotlin.multiplatform.get().pluginId)
   alias(libs.plugins.arrowGradleConfig.kotlin)
   alias(libs.plugins.arrowGradleConfig.publish)
 }
@@ -11,27 +11,27 @@ kotlin {
 apply(from = property("TEST_COVERAGE"))
 apply(from = property("ANIMALSNIFFER_MPP"))
 
-dependencies {
-  implementation(libs.ksp)
-
-  testImplementation(libs.kotlin.stdlibJDK8)
-  testImplementation(libs.junitJupiter)
-  testImplementation(libs.junitJupiterEngine)
-  testImplementation(libs.assertj)
-  testImplementation(libs.classgraph)
-  testImplementation(libs.kotlinCompileTesting) {
-    exclude(
-      group = libs.classgraph.get().module.group,
-      module = libs.classgraph.get().module.name
-    )
-    exclude(
-      group = libs.kotlin.stdlibJDK8.get().module.group,
-      module = libs.kotlin.stdlibJDK8.get().module.name
-    )
+kotlin {
+  sourceSets {
+    jvmMain {
+      dependencies {
+        implementation(libs.ksp)
+      }
+    }
+    jvmTest {
+      dependencies {
+        implementation(libs.kotlin.stdlibJDK8)
+        implementation(libs.junitJupiter)
+        implementation(libs.junitJupiterEngine)
+        implementation(libs.assertj)
+        implementation(libs.classgraph)
+        implementation(libs.kotlinCompileTesting)
+        implementation(libs.kotlinCompileTestingKsp)
+        runtimeOnly(projects.arrowOpticsKspPlugin)
+        runtimeOnly(projects.arrowAnnotations)
+        runtimeOnly(projects.arrowCore)
+        runtimeOnly(projects.arrowOptics)
+      }
+    }
   }
-  testImplementation(libs.kotlinCompileTestingKsp)
-  testRuntimeOnly(projects.arrowOpticsKspPlugin)
-  testRuntimeOnly(projects.arrowAnnotations)
-  testRuntimeOnly(projects.arrowCore)
-  testRuntimeOnly(projects.arrowOptics)
 }

arrow-libs/optics/arrow-optics-ksp-plugin/src/jvmMain/kotlin/arrow/optics/plugin/OpticsProcessor.kt

@@ -7,6 +7,7 @@ import arrow.optics.plugin.internals.join
 import arrow.optics.plugin.internals.noCompanion
 import arrow.optics.plugin.internals.otherClassTypeErrorMessage
 import arrow.optics.plugin.internals.snippets
+import arrow.optics.plugin.internals.typeParametersErrorMessage
 import com.google.devtools.ksp.processing.CodeGenerator
 import com.google.devtools.ksp.processing.Dependencies
 import com.google.devtools.ksp.processing.KSPLogger
@@ -36,14 +37,21 @@ class OpticsProcessor(private val codegen: CodeGenerator, private val logger: KS
       return
     }
 
+    // check that it does not have type arguments
+    if (klass.typeParameters.isNotEmpty()) {
+      logger.error(klass.simpleName.asString().typeParametersErrorMessage, klass)
+      return
+    }
+
     // check that the companion object exists
-    val companion = klass.companionObject
-    if (companion == null) {
+    if (klass.companionObject == null) {
       logger.error(klass.simpleName.asString().noCompanion, klass)
       return
     }
 
-    adt(klass, logger).snippets().groupBy(Snippet::fqName).values.map(List<Snippet>::join).forEach {
+    val adts = adt(klass, logger)
+    val snippets = adts.snippets()
+    snippets.groupBy(Snippet::fqName).values.map(List<Snippet>::join).forEach {
       val writer =
         codegen
           .createNewFile(

arrow-libs/optics/arrow-optics-ksp-plugin/src/jvmMain/kotlin/arrow/optics/plugin/internals/errors.kt

@@ -5,8 +5,14 @@ val String.otherClassTypeErrorMessage
     """
       |$this cannot be annotated with @optics
       | ^
-      |
-      |Only data and sealed classes can be annotated with @optics annotation""".trimMargin()
+      |Only data and sealed classes can be annotated with @optics""".trimMargin()
+
+val String.typeParametersErrorMessage
+  get() =
+    """
+      |$this cannot be annotated with @optics
+      | ^
+      |Only classes with no type parameters can be annotated with @optics""".trimMargin()
 
 val String.lensErrorMessage
   get() =
@@ -56,10 +62,14 @@ val String.dslErrorMessage
   get() =
     """
       |Cannot generate DSL (arrow.optics.BoundSetter) for $this
-      |                                           ^
+      |                                                    ^
       |arrow.optics.OpticsTarget.DSL is an invalid @optics argument for $this.
       |It is only valid for data classes and sealed classes.
       """.trimMargin()
 
 val String.noCompanion
-  get() = "@optics annotated class $this needs to declare companion object."
+  get() =
+    """
+      |$this must declare a companion object
+      | ^
+      |A companion object is required for the generated optics""".trimMargin()

arrow-libs/optics/arrow-optics-ksp-plugin/src/jvmTest/kotlin/arrow/optics/plugin/LensTests.kt

@@ -1,5 +1,6 @@
 package arrow.optics.plugin
 
+import arrow.optics.plugin.internals.typeParametersErrorMessage
 import org.junit.jupiter.api.Test
 
 class LensTests {
@@ -32,4 +33,34 @@ class LensTests {
       |val r = i != null
       """.evals("r" to true)
   }
+
+  @Test
+  fun `Lenses which mentions imported elements`() {
+    """
+      |$imports
+      |import kotlin.time.Duration
+      |
+      |@optics
+      |data class OpticsTest(val time: Duration) {
+      |  companion object
+      |}
+      |
+      |val i: Lens<OpticsTest, Duration> = OpticsTest.time
+      |val r = i != null
+      """.evals("r" to true)
+  }
+
+  @Test
+  fun `Lenses which mentions type arguments`() {
+    """
+      |$imports
+      |@optics
+      |data class OpticsTest<A>(val field: A) {
+      |  companion object
+      |}
+      |
+      |val i: Lens<OpticsTest, Int> = OpticsTest<Int>.time
+      |val r = i != null
+      """.failsWith { it.contains("OpticsTest".typeParametersErrorMessage) }
+  }
 }