fix: update init function to handle nullable types and add UUID test …

…case

src/index.spec.ts

@@ -16,6 +16,12 @@ describe("make empty", () => {
     expect(empty(schema)).toBeNull();
   });
 
+  it("uuid", () => {
+    const schema = z.string().uuid();
+    expect(init(schema).length).toBe(36);
+    expect(empty(schema)).toBeNull();
+  });
+
   it.each([
     ["", z.number(), 0],
     ["10-", z.number().min(10), 10],
@@ -228,35 +234,35 @@ describe("make empty", () => {
   describe("nullable", () => {
     it("string", () => {
       const schema = z.string().nullable();
-      expect(init(schema)).toBe("");
+      expect(init(schema)).toBeNull();
       expect(empty(schema)).toBeNull();
     });
     it("number", () => {
       const schema = z.number().nullable();
-      expect(init(schema)).toBe(0);
+      expect(init(schema)).toBeNull();
       expect(empty(schema)).toBeNull();
     });
     it("array", () => {
       const schema = z.array(z.string()).nullable();
-      expect(init(schema)).toStrictEqual([]);
+      expect(init(schema)).toBeNull();
       expect(empty(schema)).toStrictEqual([]);
     });
   });
 
   describe("nullish", () => {
     it("string", () => {
       const schema = z.string().nullish();
-      expect(init(schema)).toBe("");
+      expect(init(schema)).toBeNull();
       expect(empty(schema)).toBeNull();
     });
     it("number", () => {
       const schema = z.number().nullish();
-      expect(init(schema)).toBe(0);
+      expect(init(schema)).toBeNull();
       expect(empty(schema)).toBeNull();
     });
     it("array", () => {
       const schema = z.array(z.string()).nullish();
-      expect(init(schema)).toStrictEqual([]);
+      expect(init(schema)).toBeNull();
       expect(empty(schema)).toStrictEqual([]);
     });
   });

src/index.ts

@@ -3,6 +3,10 @@ import type { ZodTypeAny, input, output } from "zod";
 
 export function init<T extends ZodTypeAny>(schema: T): output<T> {
   const def = schema._def;
+  if (schema.isNullable() && def.typeName !== "ZodDefault") {
+    return null;
+  }
+
   switch (def.typeName) {
     case "ZodObject": {
       const outputObject: Record<string, unknown> = {};
@@ -76,17 +80,13 @@ export function init<T extends ZodTypeAny>(schema: T): output<T> {
     case "ZodNull":
     case "ZodAny":
       return null;
-    case "ZodNullable":
     case "ZodOptional":
       return init(def.innerType);
     // case "ZodUndefined":
     // case "ZodVoid":
     // case "ZodUnknown":
     // case "ZodNever":
     default:
-      if (schema.isNullable()) {
-        return null;
-      }
       return undefined;
   }
 }