zod example

zod-example.ts

// Used Deno
// 
// If you're using Node.js, you should import it from node_modules
// And note that you must enable strict mode in your tsconfig.json
// see https://github.com/colinhacks/zod#requirements
import { z } from "https://deno.land/x/zod@v3.17.3/mod.ts";

const userSchema = z.object({
  id: z.string(),
  name: z.string(),
  email: z.string().email(),
  phone: z.string().optional(),
  group: z.nullable(z.string()),
});

type User = z.infer<typeof userSchema>;

const _exampleUser: User = {
  id: "1234",
  name: "example",
  email: "example@example.com",
  phone: "000-123-4567",
  group: null,
};

// parsing
try {
  userSchema.parse({ id: 1 });
} catch (e) {
  // Following ZodError should be thrown for each invalid field
  // Note that `e.message` is a `string` not an array of objects.
  // [
  //   {
  //     "code": "invalid_type",
  //     "expected": "string",
  //     "received": "number",
  //     "path": [
  //       "id"
  //     ],
  //     "message": "Expected string, received number"
  //   },
  //   ...
  // ]

  // This line should print the first error message
  console.error(JSON.parse(e.message)[0]);
}

// "safe" parsing
const parsingResult = userSchema.safeParse({ id: '1' });
// a condition for type narrowing 
if (!parsingResult.success) {
  // you can use .error on `success=false`
  console.group('SafeParsing');
  console.error(JSON.parse(parsingResult.error.message));
  console.groupEnd();
} else {
  // now you can use .data `success=true`
  console.log(parsingResult.data);
}