fix: apply modifiers (nullable) to additionalProperties value type in zod generator

Copilot · mrlubos · Copilot · commit 77c16c699ca6 · 2026-02-25T22:43:38.000Z
Co-authored-by: mrlubos &lt;12529395+mrlubos@users.noreply.github.com&gt;
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: z.optional(zNullableObject)
 });
 
+/**
+ * An object with additional properties that can be null
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), z.nullable(zNullableObject));
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: z.optional(zNullableObject)
 });
 
+/**
+ * An object with additional properties that can be null (anyOf ref + null)
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), z.nullable(zNullableObject));
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null (anyOf ref + null)
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null (anyOf ref + null)
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: z.optional(zNullableObject)
 });
 
+/**
+ * An object with additional properties that can be null
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), z.nullable(zNullableObject));
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: z.optional(zNullableObject)
 });
 
+/**
+ * An object with additional properties that can be null (anyOf ref + null)
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), z.nullable(zNullableObject));
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null (anyOf ref + null)
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/default/zod.gen.ts
@@ -721,6 +721,11 @@ export const zModelWithNullableObject = z.object({
     data: zNullableObject.optional()
 });
 
+/**
+ * An object with additional properties that can be null (anyOf ref + null)
+ */
+export const zModelWithAdditionalPropertiesRef = z.record(z.string(), zNullableObject.nullable());
+
 export const zModelWithOneOfEnum = z.union([
     z.object({
         foo: z.enum(['Bar'])
diff --git a/packages/openapi-ts/src/plugins/zod/mini/toAst/object.ts b/packages/openapi-ts/src/plugins/zod/mini/toAst/object.ts
@@ -29,7 +29,7 @@ type ExtendedContext = ObjectResolverContext & {
 };
 
 function additionalPropertiesNode(ctx: ExtendedContext): Chain | null | undefined {
-  const { schema, walk, walkerCtx } = ctx;
+  const { applyModifiers, schema, walk, walkerCtx } = ctx;
 
   if (
     !schema.additionalProperties ||
@@ -43,7 +43,8 @@ function additionalPropertiesNode(ctx: ExtendedContext): Chain | null | undefine
     childContext(walkerCtx, 'additionalProperties'),
   );
   if (additionalResult.hasLazyExpression) ctx.utils.ast.hasLazyExpression = true;
-  return additionalResult.expression.expression;
+  const ast = applyModifiers(additionalResult, {});
+  return ast.expression;
 }
 
 function baseNode(ctx: ExtendedContext): Chain {
diff --git a/packages/openapi-ts/src/plugins/zod/v3/toAst/object.ts b/packages/openapi-ts/src/plugins/zod/v3/toAst/object.ts
@@ -29,7 +29,7 @@ type ExtendedContext = ObjectResolverContext & {
 };
 
 function additionalPropertiesNode(ctx: ExtendedContext): Chain | null | undefined {
-  const { schema, walk, walkerCtx } = ctx;
+  const { applyModifiers, schema, walk, walkerCtx } = ctx;
 
   if (
     !schema.additionalProperties ||
@@ -43,7 +43,8 @@ function additionalPropertiesNode(ctx: ExtendedContext): Chain | null | undefine
     childContext(walkerCtx, 'additionalProperties'),
   );
   if (additionalResult.hasLazyExpression) ctx.utils.ast.hasLazyExpression = true;
-  return additionalResult.expression.expression;
+  const ast = applyModifiers(additionalResult, {});
+  return ast.expression;
 }
 
 function baseNode(ctx: ExtendedContext): Chain {
diff --git a/packages/openapi-ts/src/plugins/zod/v4/toAst/object.ts b/packages/openapi-ts/src/plugins/zod/v4/toAst/object.ts
@@ -29,7 +29,7 @@ type ExtendedContext = ObjectResolverContext & {
 };
 
 function additionalPropertiesNode(ctx: ExtendedContext): Chain | null | undefined {
-  const { schema, walk, walkerCtx } = ctx;
+  const { applyModifiers, schema, walk, walkerCtx } = ctx;
 
   if (
     !schema.additionalProperties ||
@@ -43,7 +43,8 @@ function additionalPropertiesNode(ctx: ExtendedContext): Chain | null | undefine
     childContext(walkerCtx, 'additionalProperties'),
   );
   if (additionalResult.hasLazyExpression) ctx.utils.ast.hasLazyExpression = true;
-  return additionalResult.expression.expression;
+  const ast = applyModifiers(additionalResult, {});
+  return ast.expression;
 }
 
 function baseNode(ctx: ExtendedContext): Chain {
diff --git a/specs/3.0.x/full.yaml b/specs/3.0.x/full.yaml
@@ -2208,6 +2208,13 @@ components:
       properties:
         data:
           $ref: '#/components/schemas/NullableObject'
+    ModelWithAdditionalPropertiesRef:
+      type: object
+      description: An object with additional properties that can be null
+      additionalProperties:
+        nullable: true
+        allOf:
+          - $ref: '#/components/schemas/NullableObject'
     ModelWithOneOfEnum:
       oneOf:
         - type: object
diff --git a/specs/3.1.x/full.yaml b/specs/3.1.x/full.yaml
@@ -2248,6 +2248,13 @@ components:
       properties:
         data:
           $ref: '#/components/schemas/NullableObject'
+    ModelWithAdditionalPropertiesRef:
+      type: object
+      description: An object with additional properties that can be null (anyOf ref + null)
+      additionalProperties:
+        anyOf:
+          - $ref: '#/components/schemas/NullableObject'
+          - type: 'null'
     ModelWithOneOfEnum:
       oneOf:
         - type: object
