Resolve the issue with recursive and nested Zod schemas

src/_vendor/zod-to-json-schema/Options.ts

@@ -38,38 +38,45 @@ export type Options<Target extends Targets = 'jsonSchema7'> = {
   openaiStrictMode?: boolean;
 };
 
-export const defaultOptions: Options = {
-  name: undefined,
-  $refStrategy: 'root',
-  basePath: ['#'],
-  effectStrategy: 'input',
-  pipeStrategy: 'all',
-  dateStrategy: 'format:date-time',
-  mapStrategy: 'entries',
-  nullableStrategy: 'from-target',
-  removeAdditionalStrategy: 'passthrough',
-  definitionPath: 'definitions',
-  target: 'jsonSchema7',
-  strictUnions: false,
-  definitions: {},
-  errorMessages: false,
-  markdownDescription: false,
-  patternStrategy: 'escape',
-  applyRegexFlags: false,
-  emailStrategy: 'format:email',
-  base64Strategy: 'contentEncoding:base64',
-  nameStrategy: 'ref',
-};
-
 export const getDefaultOptions = <Target extends Targets>(
   options: Partial<Options<Target>> | string | undefined,
-) =>
-  (typeof options === 'string' ?
-    {
-      ...defaultOptions,
-      name: options,
-    }
-  : {
-      ...defaultOptions,
-      ...options,
-    }) as Options<Target>;
+) => {
+  // Move the default options into the function to prevent the 'definitions' being mutated in each run
+  const defaultOptions: Options = {
+    name: undefined,
+    $refStrategy: 'root',
+    basePath: ['#'],
+    effectStrategy: 'input',
+    pipeStrategy: 'all',
+    dateStrategy: 'format:date-time',
+    mapStrategy: 'entries',
+    nullableStrategy: 'from-target',
+    removeAdditionalStrategy: 'passthrough',
+    definitionPath: 'definitions',
+    target: 'jsonSchema7',
+    strictUnions: false,
+    definitions: {},
+    errorMessages: false,
+    markdownDescription: false,
+    patternStrategy: 'escape',
+    applyRegexFlags: false,
+    emailStrategy: 'format:email',
+    base64Strategy: 'contentEncoding:base64',
+    nameStrategy: 'ref',
+  };
+  return (
+    typeof options === 'string' ?
+      {
+        ...defaultOptions,
+        // Create a new object to avoid mutating the default options
+        basePath: ['#'],
+        definitions: {},
+        name: options,
+      }
+    : {
+        ...defaultOptions,
+        basePath: ['#'],
+        definitions: {},
+        ...options,
+      }) as Options<Target>;
+};

src/_vendor/zod-to-json-schema/zodToJsonSchema.ts

@@ -49,14 +49,26 @@ const zodToJsonSchema = <Target extends Targets = 'jsonSchema7'>(
     }
 
     const definitions: Record<string, any> = {};
+    const processedKeys = new Set();
 
-    for (const [name, zodSchema] of Object.entries(refs.definitions)) {
-      definitions[name] =
-        parseDef(
-          zodDef(zodSchema),
-          { ...refs, currentPath: [...refs.basePath, refs.definitionPath, name] },
-          true,
-        ) ?? {};
+    // use while loop to add newly created definitions in `parseDef` to the list
+    while (true) {
+      const newKeys = Object.keys(refs.definitions).filter((key) => !processedKeys.has(key));
+
+      if (newKeys.length === 0) break;
+
+      for (const key of newKeys) {
+        const schema = refs.definitions[key];
+        if (schema) {
+          definitions[key] =
+            parseDef(
+              zodDef(schema),
+              { ...refs, currentPath: [...refs.basePath, refs.definitionPath, key] },
+              true,
+            ) ?? {};
+          processedKeys.add(key);
+        }
+      }
     }
 
     return definitions;

tests/lib/__snapshots__/parser.test.ts.snap

@@ -84,6 +84,34 @@ exports[`.parse() zod nested schema extraction 2`] = `
 "
 `;
 
+exports[`.parse() zod recursive schema extraction 2`] = `
+"{
+  "id": "chatcmpl-9vdbw9dekyUSEsSKVQDhTxA2RCxcK",
+  "object": "chat.completion",
+  "created": 1723523988,
+  "model": "gpt-4o-2024-08-06",
+  "choices": [
+    {
+      "index": 0,
+      "message": {
+        "role": "assistant",
+        "content": "{\\"linked_list\\":{\\"value\\":1,\\"next\\":{\\"value\\":2,\\"next\\":{\\"value\\":3,\\"next\\":{\\"value\\":4,\\"next\\":{\\"value\\":5,\\"next\\":null}}}}}}",
+        "refusal": null
+      },
+      "logprobs": null,
+      "finish_reason": "stop"
+    }
+  ],
+  "usage": {
+    "prompt_tokens": 40,
+    "completion_tokens": 38,
+    "total_tokens": 78
+  },
+  "system_fingerprint": "fp_2a322c9ffc"
+}
+"
+`;
+
 exports[`.parse() zod top-level recursive schemas 1`] = `
 "{
   "id": "chatcmpl-9uLhw79ArBF4KsQQOlsoE68m6vh6v",

tests/lib/parser.test.ts

@@ -525,13 +525,6 @@ describe('.parse()', () => {
           "$schema": "http://json-schema.org/draft-07/schema#",
           "additionalProperties": false,
           "definitions": {
-            "contactPerson_properties_person1_properties_name": {
-              "type": "string",
-            },
-            "contactPerson_properties_person1_properties_phone_number": {
-              "nullable": true,
-              "type": "string",
-            },
             "query": {
               "additionalProperties": false,
               "properties": {
@@ -616,6 +609,21 @@ describe('.parse()', () => {
                 },
               ],
             },
+            "query_properties_fields_items_anyOf_0_properties_metadata_anyOf_0": {
+              "additionalProperties": false,
+              "properties": {
+                "foo": {
+                  "$ref": "#/definitions/query_properties_fields_items_anyOf_0_properties_metadata_anyOf_0_properties_foo",
+                },
+              },
+              "required": [
+                "foo",
+              ],
+              "type": "object",
+            },
+            "query_properties_fields_items_anyOf_0_properties_metadata_anyOf_0_properties_foo": {
+              "type": "string",
+            },
           },
           "properties": {
             "fields": {
@@ -783,5 +791,165 @@ describe('.parse()', () => {
         }
       `);
     });
+
+    test('recursive schema extraction', async () => {
+      const baseLinkedListNodeSchema = z.object({
+        value: z.number(),
+      });
+      type LinkedListNode = z.infer<typeof baseLinkedListNodeSchema> & {
+        next: LinkedListNode | null;
+      };
+      const linkedListNodeSchema: z.ZodType<LinkedListNode> = baseLinkedListNodeSchema.extend({
+        next: z.lazy(() => z.union([linkedListNodeSchema, z.null()])),
+      });
+
+      // Define the main schema
+      const mainSchema = z.object({
+        linked_list: linkedListNodeSchema,
+      });
+
+      expect(zodResponseFormat(mainSchema, 'query').json_schema.schema).toMatchInlineSnapshot(`
+        {
+          "$schema": "http://json-schema.org/draft-07/schema#",
+          "additionalProperties": false,
+          "definitions": {
+            "query": {
+              "additionalProperties": false,
+              "properties": {
+                "linked_list": {
+                  "additionalProperties": false,
+                  "properties": {
+                    "next": {
+                      "anyOf": [
+                        {
+                          "$ref": "#/definitions/query_properties_linked_list",
+                        },
+                        {
+                          "type": "null",
+                        },
+                      ],
+                    },
+                    "value": {
+                      "type": "number",
+                    },
+                  },
+                  "required": [
+                    "value",
+                    "next",
+                  ],
+                  "type": "object",
+                },
+              },
+              "required": [
+                "linked_list",
+              ],
+              "type": "object",
+            },
+            "query_properties_linked_list": {
+              "additionalProperties": false,
+              "properties": {
+                "next": {
+                  "$ref": "#/definitions/query_properties_linked_list_properties_next",
+                },
+                "value": {
+                  "$ref": "#/definitions/query_properties_linked_list_properties_value",
+                },
+              },
+              "required": [
+                "value",
+                "next",
+              ],
+              "type": "object",
+            },
+            "query_properties_linked_list_properties_next": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/query_properties_linked_list",
+                },
+                {
+                  "type": "null",
+                },
+              ],
+            },
+            "query_properties_linked_list_properties_value": {
+              "type": "number",
+            },
+          },
+          "properties": {
+            "linked_list": {
+              "additionalProperties": false,
+              "properties": {
+                "next": {
+                  "anyOf": [
+                    {
+                      "$ref": "#/definitions/query_properties_linked_list",
+                    },
+                    {
+                      "type": "null",
+                    },
+                  ],
+                },
+                "value": {
+                  "type": "number",
+                },
+              },
+              "required": [
+                "value",
+                "next",
+              ],
+              "type": "object",
+            },
+          },
+          "required": [
+            "linked_list",
+          ],
+          "type": "object",
+        }
+      `);
+
+      const completion = await makeSnapshotRequest(
+        (openai) =>
+          openai.beta.chat.completions.parse({
+            model: 'gpt-4o-2024-08-06',
+            messages: [
+              {
+                role: 'system',
+                content:
+                  "You are a helpful assistant. Generate a data model according to the user's instructions.",
+              },
+              { role: 'user', content: 'create a linklist from 1 to 5' },
+            ],
+            response_format: zodResponseFormat(mainSchema, 'query'),
+          }),
+        2,
+      );
+
+      expect(completion.choices[0]?.message).toMatchInlineSnapshot(`
+        {
+          "content": "{"linked_list":{"value":1,"next":{"value":2,"next":{"value":3,"next":{"value":4,"next":{"value":5,"next":null}}}}}}",
+          "parsed": {
+            "linked_list": {
+              "next": {
+                "next": {
+                  "next": {
+                    "next": {
+                      "next": null,
+                      "value": 5,
+                    },
+                    "value": 4,
+                  },
+                  "value": 3,
+                },
+                "value": 2,
+              },
+              "value": 1,
+            },
+          },
+          "refusal": null,
+          "role": "assistant",
+          "tool_calls": [],
+        }
+      `);
+    });
   });
 });