Working with Records, Maps, Sets, and Enums in Zod

Using z.record()

z.record() defines objects with dynamic keys (like dictionaries or hash maps).

Example: Key-value object of strings

const StringMap = z.record(z.string());

StringMap.parse({
  en: "Hello",
  fr: "Bonjour",
  he: "שלום",
}); // ✅

All values must match the provided schema.

Example: Nested object values

const ScoreMap = z.record(z.object({ score: z.number(), passed: z.boolean() }));

ScoreMap.parse({
  math: { score: 95, passed: true },
  history: { score: 82, passed: true },
}); // ✅

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Working with z.map()

Zod supports the native JavaScript Map object:

const mapSchema = z.map(z.string(), z.number());

mapSchema.parse(
  new Map([
    ["a", 1],
    ["b", 2],
  ])
); // ✅

Useful when using Map instances instead of plain objects.

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Validating Sets with z.set()

Zod can validate JavaScript Set objects too:

const setSchema = z.set(z.string());

setSchema.parse(new Set(["apple", "banana"])); // ✅

You can also enforce minimum or maximum size:

const limitedSet = z.set(z.number()).min(2).max(5);

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Creating Enums with z.enum()

Zod’s z.enum() creates a strict list of allowed string values:

const RoleSchema = z.enum(["admin", "user", "guest"]);

RoleSchema.parse("admin"); // ✅
RoleSchema.parse("manager"); // ❌

Zod will infer a union type automatically:

type Role = z.infer<typeof roleschema>;
// ➜ "admin" | "user" | "guest"

Getting Enum Options

RoleSchema.options; // ➜ ["admin", "user", "guest"]

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Using Native TypeScript Enums

Zod also supports TypeScript enums:

enum Direction {
  Up = "up",
  Down = "down",
}

const DirectionSchema = z.nativeEnum(Direction);

DirectionSchema.parse("up"); // ✅
DirectionSchema.parse(Direction.Down); // ✅

Great for working with shared enums across front-end and back-end apps.

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Summary

• Use z.record() for key-value objects with unknown keys
• Use z.map() and z.set() for native JS Map and Set support
• Use z.enum() for strict union types and validation
• Use z.nativeEnum() when working with TypeScript enums

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Next: Lesson 11 – Zod and Async Validation with Promises

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