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display-name-schema

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Validates a trimmed, Unicode-normalized display label without restricting names to one writing system.

Code

Section titled “Code”
display-name-schema.ts
import * as z from "zod";


const DISPLAY_NAME_MIN_LENGTH = 1;
const DISPLAY_NAME_MAX_LENGTH = 80;
const CONTROL_CHARACTER_PATTERN = /[\u0000-\u001f\u007f-\u009f]/u;
const codePointLength = (value: string): number => Array.from(value).length;
const isWellFormedUnicode = (value: string): boolean => {
  for (let index = 0; index < value.length; index += 1) {
    const codeUnit = value.charCodeAt(index);
    if (codeUnit >= 0xd800 && codeUnit <= 0xdbff) {
      const nextCodeUnit = value.charCodeAt(index + 1);
      if (!(nextCodeUnit >= 0xdc00 && nextCodeUnit <= 0xdfff)) return false;
      index += 1;
    } else if (codeUnit >= 0xdc00 && codeUnit <= 0xdfff) {
      return false;
    }
  }
  return true;
};


/** Validates and brands a trimmed, NFC-normalized display name. */
export const displayNameSchema = z
  .string({ error: "Display name must be a string" })
  .check(
    z.trim(),
    z.refine(isWellFormedUnicode, {
      error: "Display name must contain only well-formed Unicode",
    }),
    z.normalize("NFC"),
    z.refine((value) => !CONTROL_CHARACTER_PATTERN.test(value), {
      error: "Display name must not contain control characters",
    }),
    z.refine(
      (value) => codePointLength(value) >= DISPLAY_NAME_MIN_LENGTH,
      { error: "Display name is required" },
    ),
    z.refine(
      (value) => codePointLength(value) <= DISPLAY_NAME_MAX_LENGTH,
      {
        error: `Display name must contain at most ${DISPLAY_NAME_MAX_LENGTH} characters`,
      },
    ),
  )
  .brand<"DisplayName">()
  .meta({
    title: "Display name",
    description:
      "A trimmed, NFC-normalized display name containing at most 80 Unicode code points.",
    examples: ["Ada Lovelace"],
  });


export type DisplayName = z.infer<typeof displayNameSchema>;

Download

Section titled “Download”
Terminal
wget -O src/schemas/display-name-schema.ts https://raw.githubusercontent.com/jrTilak/lazykit/HEAD/registry/zod-schemas/display-name-schema.ts

Examples

Section titled “Examples”
display-name-schema.example.ts
import {
  displayNameSchema,
  type DisplayName,
} from "./display-name-schema";


const displayName = displayNameSchema.parse("  Ada Lovelace  ");


const greet = (name: DisplayName) => {
  console.log(`Hello, ${name}`);
};


greet(displayName);
// Output: Hello, Ada Lovelace

Props

Section titled “Props”
  • input (string) — The display label to canonicalize.

Returns

Section titled “Returns”

DisplayName, a string branded with "DisplayName". Outer whitespace is trimmed, Unicode text is normalized to NFC, and the result must contain 1 to 80 Unicode code points. Unpaired UTF-16 surrogates are rejected.

Ordinary internal whitespace is preserved. C0 and C1 control characters, including internal tabs and line breaks, are rejected after outer whitespace is trimmed. The schema deliberately permits all scripts, emoji, apostrophes, hyphens, and other well-formed characters; it validates a display label, not a person’s legal or culturally specific name.