From 9556d52f91a5abb680e74534534f92dfb0e6e542 Mon Sep 17 00:00:00 2001
From: MaxwellAt <exnoob123@gmail.com>
Date: Tue, 5 Aug 2025 21:01:16 -0300
Subject: [PATCH] fix: correct additionalProperties condition in all Zod plugin
 versions

- Changed from Object.keys(properties) to Object.keys(schema.properties)
- Added ZodType for circular references in v4 plugin
- Removed type === 'object' restriction for additionalProperties
- Applied consistent fixes across v3, v4, and mini plugin versions
---
 README.md                                     |  2 +-
 .../openapi-ts/src/plugins/zod/mini/plugin.ts |  3 +--
 .../openapi-ts/src/plugins/zod/v3/plugin.ts   |  3 +--
 .../openapi-ts/src/plugins/zod/v4/plugin.ts   | 20 +++++++++++++++++--
 4 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index f5c4d7a3c..6b53016ec 120000
--- a/README.md
+++ b/README.md
@@ -1 +1 @@
-packages/openapi-ts/README.md
\ No newline at end of file
+packages/openapi-ts/README.md
diff --git a/packages/openapi-ts/src/plugins/zod/mini/plugin.ts b/packages/openapi-ts/src/plugins/zod/mini/plugin.ts
index 4a8da7cef..bc6549dde 100644
--- a/packages/openapi-ts/src/plugins/zod/mini/plugin.ts
+++ b/packages/openapi-ts/src/plugins/zod/mini/plugin.ts
@@ -469,8 +469,7 @@ const objectTypeToZodSchema = ({
 
   if (
     schema.additionalProperties &&
-    schema.additionalProperties.type === 'object' &&
-    !Object.keys(properties).length
+    (!schema.properties || !Object.keys(schema.properties).length)
   ) {
     const zodSchema = schemaToZodSchema({
       plugin,
diff --git a/packages/openapi-ts/src/plugins/zod/v3/plugin.ts b/packages/openapi-ts/src/plugins/zod/v3/plugin.ts
index a370c991a..fcd2412d3 100644
--- a/packages/openapi-ts/src/plugins/zod/v3/plugin.ts
+++ b/packages/openapi-ts/src/plugins/zod/v3/plugin.ts
@@ -391,8 +391,7 @@ const objectTypeToZodSchema = ({
 
   if (
     schema.additionalProperties &&
-    schema.additionalProperties.type === 'object' &&
-    !Object.keys(properties).length
+    (!schema.properties || !Object.keys(schema.properties).length)
   ) {
     const zodSchema = schemaToZodSchema({
       plugin,
diff --git a/packages/openapi-ts/src/plugins/zod/v4/plugin.ts b/packages/openapi-ts/src/plugins/zod/v4/plugin.ts
index 305c9ea9e..4114a2480 100644
--- a/packages/openapi-ts/src/plugins/zod/v4/plugin.ts
+++ b/packages/openapi-ts/src/plugins/zod/v4/plugin.ts
@@ -431,8 +431,7 @@ const objectTypeToZodSchema = ({
 
   if (
     schema.additionalProperties &&
-    schema.additionalProperties.type === 'object' &&
-    !Object.keys(properties).length
+    (!schema.properties || !Object.keys(schema.properties).length)
   ) {
     const zodSchema = schemaToZodSchema({
       plugin,
@@ -458,6 +457,15 @@ const objectTypeToZodSchema = ({
     if (zodSchema.hasCircularReference) {
       result.hasCircularReference = true;
     }
+
+    // Return with typeName for circular references
+    if (result.hasCircularReference) {
+      return {
+        ...result,
+        typeName: 'ZodType',
+      } as ZodSchema;
+    }
+
     return result as Omit<ZodSchema, 'typeName'>;
   }
 
@@ -469,6 +477,14 @@ const objectTypeToZodSchema = ({
     parameters: [ts.factory.createObjectLiteralExpression(properties, true)],
   });
 
+  // Return with typeName for circular references (AnyZodObject doesn't exist in Zod v4, use ZodType)
+  if (result.hasCircularReference) {
+    return {
+      ...result,
+      typeName: 'ZodType',
+    } as ZodSchema;
+  }
+
   return result as Omit<ZodSchema, 'typeName'>;
 };
 
-- 
2.51.2