fix: Date cannot be represented in JSON Schema

Author: omermecitoglu

src/core/zod-to-openapi.ts

@@ -1,6 +1,29 @@
-import { type ZodType, z } from "zod";
+import { type ZodObject, type ZodType, z } from "zod";
 import type { SchemaObject } from "@omer-x/openapi-types/schema";
 
+function fixSchema(schema: ZodType<unknown>): ZodType<unknown> {
+  if ("unwrap" in schema && typeof schema.unwrap === "function") {
+    switch (schema._zod.def.type) {
+      case "nullable": return fixSchema(schema.unwrap()).nullable();
+      case "optional": return fixSchema(schema.unwrap()).optional();
+      case "readonly": return fixSchema(schema.unwrap()).readonly();
+      case "array": return fixSchema(schema.unwrap()).array();
+      default: throw new Error(`${schema._zod.def.type} type is not covered in fixSchema (@omer-x/next-openapi-json-generator")`);
+    }
+  }
+  if (schema._zod.def.type === "date") {
+    return z.iso.datetime();
+  }
+  if (schema._zod.def.type === "object") {
+    const { shape } = schema as ZodObject;
+    const entries = Object.entries(shape);
+    const alteredEntries = entries.map(([propName, prop]) => [propName, fixSchema(prop)]);
+    const newShape = Object.fromEntries(alteredEntries);
+    return z.object(newShape);
+  }
+  return schema;
+}
+
 export default function convertToOpenAPI(schema: ZodType<unknown>, isArray: boolean) {
-  return z.toJSONSchema(isArray ? schema.array() : schema) as SchemaObject;
+  return z.toJSONSchema(fixSchema(isArray ? schema.array() : schema)) as SchemaObject;
 }