Ignore ZodNever and ZodUndefined (#202)

README.md

@@ -521,6 +521,7 @@ For example in `z.string().nullable()` will be rendered differently
 - ZodLiteral
 - ZodNativeEnum
   - supporting `string`, `number` and combined enums.
+- ZodNever
 - ZodNull
 - ZodNullable
 - ZodNumber
@@ -543,6 +544,7 @@ For example in `z.string().nullable()` will be rendered differently
 - ZodTuple
   - `items` mapping for `.rest()`
   - `prefixItems` mapping for OpenAPI 3.1.0+
+- ZodUndefined
 - ZodUnion
   - By default it outputs an `allOf` schema. Use `unionOneOf` to change this to output `oneOf` instead.
 - ZodUnknown

src/create/schema/parsers/object.test.ts

@@ -199,4 +199,19 @@ describe('extend', () => {
 
     expect(result).toStrictEqual(expected);
   });
+
+  it('ignores ZodNever and ZodUndefined schemas', () => {
+    const expected: oas31.SchemaObject = {
+      type: 'object',
+      properties: {
+        a: { type: 'string' },
+      },
+      required: ['a'],
+    };
+    const schema = z.object({ a: z.string(), b: z.undefined(), c: z.never() });
+
+    const result = createObjectSchema(schema, createOutputState());
+
+    expect(result).toStrictEqual(expected);
+  });
 });

src/create/schema/parsers/object.ts

@@ -185,6 +185,13 @@ export const mapProperties = (
 ): oas31.SchemaObject['properties'] =>
   Object.entries(shape).reduce<NonNullable<oas31.SchemaObject['properties']>>(
     (acc, [key, zodSchema]): NonNullable<oas31.SchemaObject['properties']> => {
+      if (
+        isZodType(zodSchema, 'ZodNever') ||
+        isZodType(zodSchema, 'ZodUndefined')
+      ) {
+        return acc;
+      }
+
       acc[key] = createSchemaObject(zodSchema, state, [`property: ${key}`]);
       return acc;
     },

src/create/schema/parsers/optional.ts

@@ -14,7 +14,11 @@ export const isOptionalSchema = (
   zodSchema: ZodTypeAny,
   state: SchemaState,
 ): boolean => {
-  if (isZodType(zodSchema, 'ZodOptional')) {
+  if (
+    isZodType(zodSchema, 'ZodOptional') ||
+    isZodType(zodSchema, 'ZodNever') ||
+    isZodType(zodSchema, 'ZodUndefined')
+  ) {
     return true;
   }