From 95feaf4e07c5fe575c3acfbc246e0f2bd941fad1 Mon Sep 17 00:00:00 2001
From: Alex Smith <a@xf.gl>
Date: Sat, 27 Jun 2026 16:14:39 +0000
Subject: [PATCH] fix(kotlin): add @Valid annotation for cascade validation on
 array/object/reference fields

The Kotlin ConstraintsPreset was missing the @Valid annotation for
array, object, and reference properties, which disabled cascading
validation. This is the same issue that was fixed for the Java
generator in #2175.

Changes:
- Add @Valid annotation for ConstrainedArrayModel, ConstrainedObjectModel,
  and ConstrainedReferenceModel properties
- Add javax.validation.Valid (or jakarta.validation.Valid) import
- Add test case verifying @Valid is rendered for nested object and array props

Fixes #2573
---
 .../kotlin/presets/ConstraintsPreset.ts       | 14 ++++++++
 .../kotlin/presets/ConstraintsPreset.spec.ts  | 35 +++++++++++++++++--
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/src/generators/kotlin/presets/ConstraintsPreset.ts b/src/generators/kotlin/presets/ConstraintsPreset.ts
index 447abadae6..8e737cd186 100644
--- a/src/generators/kotlin/presets/ConstraintsPreset.ts
+++ b/src/generators/kotlin/presets/ConstraintsPreset.ts
@@ -3,6 +3,8 @@ import {
   ConstrainedFloatModel,
   ConstrainedIntegerModel,
   ConstrainedMetaModel,
+  ConstrainedObjectModel,
+  ConstrainedReferenceModel,
   ConstrainedStringModel
 } from '../../../models';
 import { KotlinPreset } from '../KotlinPreset';
@@ -20,6 +22,9 @@ export const KOTLIN_CONSTRAINTS_PRESET: KotlinPreset = {
       renderer.dependencyManager.addDependency(
         `${importFrom}.validation.constraints.*`
       );
+      renderer.dependencyManager.addDependency(
+        `${importFrom}.validation.Valid`
+      );
       return content;
     },
     property({ renderer, property, content }) {
@@ -29,6 +34,15 @@ export const KOTLIN_CONSTRAINTS_PRESET: KotlinPreset = {
         annotations.push(renderer.renderAnnotation('NotNull', null, 'get:'));
       }
 
+      // Add @Valid for cascade validation on array/object/reference fields
+      if (
+        property.property instanceof ConstrainedReferenceModel ||
+        property.property instanceof ConstrainedObjectModel ||
+        property.property instanceof ConstrainedArrayModel
+      ) {
+        annotations.push(renderer.renderAnnotation('Valid', null, 'get:'));
+      }
+
       annotations.push(
         ...getTypeSpecificAnnotations(property.property, renderer)
       );
diff --git a/test/generators/kotlin/presets/ConstraintsPreset.spec.ts b/test/generators/kotlin/presets/ConstraintsPreset.spec.ts
index 23e84ffcca..45ebb816d0 100644
--- a/test/generators/kotlin/presets/ConstraintsPreset.spec.ts
+++ b/test/generators/kotlin/presets/ConstraintsPreset.spec.ts
@@ -12,11 +12,23 @@ describe('KOTLIN_CONSTRAINTS_PRESET', () => {
     required: ['min_number_prop', 'max_number_prop']
   };
 
+  const docWithNestedObject = {
+    $id: 'NestedClazz',
+    type: 'object',
+    properties: {
+      array_prop: { type: 'array', items: { type: 'string' } },
+      obj_prop: { type: 'object', properties: { inner: { type: 'string' } } }
+    }
+  };
+
   test('should render javax constraints annotations by default', async () => {
     const generator = new KotlinGenerator({
       presets: [KOTLIN_CONSTRAINTS_PRESET]
     });
-    const expectedDependencies = ['import javax.validation.constraints.*'];
+    const expectedDependencies = [
+      'import javax.validation.constraints.*',
+      'import javax.validation.Valid'
+    ];
 
     const models = await generator.generate(doc);
     expect(models).toHaveLength(1);
@@ -36,7 +48,10 @@ describe('KOTLIN_CONSTRAINTS_PRESET', () => {
       ]
     });
 
-    const expectedDependencies = ['import javax.validation.constraints.*'];
+    const expectedDependencies = [
+      'import javax.validation.constraints.*',
+      'import javax.validation.Valid'
+    ];
 
     const models = await generator.generate(doc);
     expect(models).toHaveLength(1);
@@ -56,11 +71,25 @@ describe('KOTLIN_CONSTRAINTS_PRESET', () => {
       ]
     });
 
-    const expectedDependencies = ['import jakarta.validation.constraints.*'];
+    const expectedDependencies = [
+      'import jakarta.validation.constraints.*',
+      'import jakarta.validation.Valid'
+    ];
 
     const models = await generator.generate(doc);
     expect(models).toHaveLength(1);
     expect(models[0].result).toMatchSnapshot();
     expect(models[0].dependencies).toEqual(expectedDependencies);
   });
+
+  test('should render @Valid annotation for array and object properties', async () => {
+    const generator = new KotlinGenerator({
+      presets: [KOTLIN_CONSTRAINTS_PRESET]
+    });
+
+    const models = await generator.generate(docWithNestedObject);
+    expect(models.length).toBeGreaterThanOrEqual(1);
+    expect(models[0].result).toContain('@get:Valid');
+    expect(models[0].result).toMatchSnapshot();
+  });
 });