fix: zod client crash when schema has circular ref (#901)

Fixes the error:

> RangeError: Maximum call stack size exceeded

Author: Eric Butler

packages/zod/src/index.ts

@@ -307,11 +307,25 @@ const deference = (
   schema: SchemaObject | ReferenceObject,
   context: ContextSpecs,
 ): SchemaObject => {
-  const { schema: resolvedSchema } = resolveRef<SchemaObject>(schema, context);
+  const refName = '$ref' in schema ? schema.$ref : undefined;
+  if (refName && context.parents?.includes(refName)) {
+    return {};
+  }
 
-  return Object.entries(resolvedSchema).reduce((acc, [key, value]) => {
-    acc[key] = deferenceScalar(value, context);
+  const childContext: ContextSpecs = {
+    ...context,
+    ...(refName
+      ? { parents: [...(context.parents || []), refName] }
+      : undefined),
+  };
 
+  const { schema: resolvedSchema } = resolveRef<SchemaObject>(
+    schema,
+    childContext,
+  );
+
+  return Object.entries(resolvedSchema).reduce((acc, [key, value]) => {
+    acc[key] = deferenceScalar(value, childContext);
     return acc;
   }, {} as any);
 };

tests/configs/zod.config.ts

@@ -0,0 +1,13 @@
+import { defineConfig } from 'orval';
+
+export default defineConfig({
+  basic: {
+    output: {
+      target: '../generated/zod',
+      client: 'zod',
+    },
+    input: {
+      target: '../specifications/circular.yaml',
+    },
+  },
+});

tests/package.json

@@ -15,6 +15,7 @@
     "generate:vue-query": "yarn orval --config ./configs/vue-query.config.ts",
     "generate:swr": "yarn orval --config ./configs/swr.config.ts",
     "generate:multi-file": "yarn orval --config ./configs/multi-file.config.ts",
+    "generate:zod": "yarn orval --config ./configs/zod.config.ts",
     "build": "tsc"
   },
   "author": "Victor Bury",
@@ -33,6 +34,7 @@
     "axios": "^0.26.1",
     "msw": "^0.35.0",
     "swr": "^2.1.2",
-    "vue": "3.2.47"
+    "vue": "3.2.47",
+    "zod": "^3.21.4"
   }
 }

tests/specifications/circular.yaml

@@ -0,0 +1,26 @@
+openapi: 3.0.0
+info:
+  title: Circular references
+  version: 0.0.0
+paths:
+  /example:
+    get:
+      summary: Example
+      responses:
+        '200':
+          description: 'Example'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Node'
+components:
+  schemas:
+    Node:
+      type: object
+      properties:
+        id:
+          type: integer
+        name:
+          type: string
+        child:
+          $ref: '#/components/schemas/Node'

tests/yarn.lock

@@ -1373,3 +1373,8 @@ yargs@^17.0.1:
     string-width "^4.2.0"
     y18n "^5.0.5"
     yargs-parser "^20.2.2"
+
+zod@^3.21.4:
+  version "3.21.4"
+  resolved "https://registry.yarnpkg.com/zod/-/zod-3.21.4.tgz#10882231d992519f0a10b5dd58a38c9dabbb64db"
+  integrity sha512-m46AKbrzKVzOzs/DZgVnG5H55N1sv1M8qZU3A8RIKbs3mrACDNeIOeilDymVb2HdmP8uwshOCF4uJ8uM9rCqJw==