Fix check for Kotlin default properties

core-processor/src/main/java/io/micronaut/inject/writer/MethodGenUtils.java

@@ -107,7 +107,7 @@ public static ExpressionDef invokeBeanConstructor(MethodElement constructor,
         List<ParameterElement> constructorArguments = Arrays.asList(constructor.getParameters());
         allowKotlinDefaults = allowKotlinDefaults && hasKotlinDefaultsParameters(constructorArguments);
 
-        List<ExpressionDef> constructorValues = constructorValues(constructor.getParameters(), values, allowKotlinDefaults);
+        List<ExpressionDef> constructorValues = constructorValues(constructor.getParameters(), values, hasValuesExpressions, allowKotlinDefaults);
 
         if (requiresReflection && !isCompanion) { // Companion and reflection not implemented
             return ClassTypeDef.of(InstantiationUtils.class).invokeStatic(
@@ -175,13 +175,22 @@ private static ExpressionDef invokeKotlinDefaultMethod(ClassElement declaringTyp
     private static List<ExpressionDef> constructorValues(ParameterElement[] constructorArguments,
                                                          @Nullable
                                                          List<? extends ExpressionDef> values,
+                                                         @Nullable
+                                                         List<? extends ExpressionDef> hasValuesExpressions,
                                                          boolean addKotlinDefaults) {
         List<ExpressionDef> expressions = new ArrayList<>(constructorArguments.length);
         for (int i = 0; i < constructorArguments.length; i++) {
             ParameterElement constructorArgument = constructorArguments[i];
             ExpressionDef value = values == null ? null : values.get(i);
             if (value != null) {
-                if (!addKotlinDefaults || value instanceof ExpressionDef.Constant constant && constant.value() != null || !constructorArgument.isPrimitive()) {
+                if (!addKotlinDefaults || value instanceof ExpressionDef.Constant constant && constant.value() != null) {
+                    expressions.add(value);
+                } else if (hasValuesExpressions != null) {
+                    // There should be a better way to check if the value exists only once
+                    expressions.add(
+                        hasValuesExpressions.get(i).isTrue().doIfElse(value, getDefaultValue(constructorArgument))
+                    );
+                } else if (!constructorArgument.isPrimitive()) {
                     expressions.add(value);
                 } else {
                     expressions.add(

test-suite-kotlin-ksp/src/test/kotlin/io/micronaut/validation/validator/ControllerCfg.kt

@@ -0,0 +1,11 @@
+package io.micronaut.validation.validator
+
+import io.micronaut.context.annotation.ConfigurationProperties
+import jakarta.validation.constraints.NotBlank
+
+@ConfigurationProperties("app.controller")
+data class ControllerCfg(
+    val enabled: Boolean = true,
+    @NotBlank val apiBase:String = "https://api.example.com/",
+    @NotBlank val something: String = "some-value"
+)

test-suite-kotlin-ksp/src/test/kotlin/io/micronaut/validation/validator/ValidatorSpec.kt

@@ -8,15 +8,24 @@ import jakarta.validation.ConstraintViolationException
 
 class ValidatorSpec {
 
+    @Test
+    fun propertiesWithValidation() {
+        val context = ApplicationContext.run()
+        val conf = context.getBean(ControllerCfg::class.java)
+        assertEquals("https://api.example.com/", conf.apiBase)
+        assertEquals(true, conf.enabled)
+        assertEquals("some-value", conf.something)
+        context.close()
+    }
+
     @Test
     fun testValidateInstance() {
         val context = ApplicationContext.run()
         val validator = context.getBean(Validator::class.java)
 
         val person = Person("", 10)
         val violations = validator.validate(person)
-//      TODO: currently fails because bean introspection API does not handle data classes
-//        assertEquals(2, violations.size)
+        assertEquals(2, violations.size)
         context.close()
     }