Type Vault is a TypeScript utility package that provides robust and validated types for common structured values like UUIDs, URLs, ISO date-times, hex colors, and more. It helps enforce correctness at runtime while maintaining strong typing at compile time.
- ✅ Runtime and compile time validation
- 🧪 Built-in helpers for immutability and nullability
Create a validated Email instance and access or update its value:
import { Email } from '@martijnvdb87/type-vault';
const email = new Email('user@example.com');
console.log(email.value); // 'user@example.com'
// Update the value with another valid email
email.value = 'foo@bar.com';
console.log(email.value); // 'foo@bar.com'Use .nullable() or pass { nullable: true } to allow null as a valid value:
import { Email } from '@martijnvdb87/type-vault';
const nullable = Email.nullable();
// Or:
const nullable = new Email(null, { nullable: true });
console.log(nullable.value); // null
// Set a valid email later
nullable.value = 'user@example.com';
console.log(nullable.value); // 'user@example.com'Use .immutable() or pass { immutable: true } to prevent value changes after initialization:
import { Email } from '@martijnvdb87/type-vault';
const immutable = Email.immutable('user@example.com');
// Or:
const immutable = new Email('user@example.com', { immutable: true });
console.log(immutable.value); // 'user@example.com'
// Attempting to change the value throws a TypeVaultValidationError
immutable.value = 'another@example.com'; // ❌ Throws errorThe Collection type lets you group validated Type Vault instances into a strongly typed, iterable array-like structure. It enforces type safety and exposes familiar array methods.
import { Collection, Email } from '@martijnvdb87/type-vault';
const collection = new Collection(Email, [
new Email('foo@example.com'),
new Email('bar@example.com'),
new Email('baz@example.com'),
]);
console.log(collection.type); // typeof Email
console.log(collection.length); // 3
console.log(collection.toArray().map((e) => e.value));
// ['foo@example.com', 'bar@example.com', 'baz@example.com']Collection instances support most native array methods, plus a few extras:
Iteration & Search: forEach, map, filter, find, findIndex, some, every, includes, indexOf, lastIndexOf
Mutation: push, pop, shift, unshift, splice, sort, reverse
Inspection & Conversion: length, toArray, toString, values, concat, reduce
Type Vault offers a rich set of validated. Each type enforces strict formatting and value constraints at runtime, and all values are stored in a normalized form to ensure consistency and predictability across your application.
For working with color values in various formats:
ColorHex– Hexadecimal color code (e.g.'#ffcc00ff','#ffcc00'or'#fc0')ColorRgb– RGB color object (e.g.'rgb(255 128 0 / 100%)','rgb(255, 128, 0)'or'rgb(255 128 0 / 1)')ColorHsl– HSL color object (e.g.'hsl(360 0 0 / 1)'or'hsl(360deg 0% 0% / 100%)')ColorOklch– OKLCH color object (e.g.'oklch(70 0.4 120deg / 25%)','oklch(70% 100% 120deg / 0.25)'or'oklch(0.7 0.4 120 / 25%)')
For representing and validating time-related values:
DateOnly– ISO date string without time (e.g.'2023-01-02'or'2023-1-2')DateTime– ISO UTC date-time string (e.g.'2023-01-02T01:23:45.123Z'or'2023-01-02T01:23:45Z')TimeOnly– ISO time string without date (e.g.'01:23:45.123'or'01:23:45')Duration– ISO 8601 duration string (e.g.'PT1H30M')Month– Valid month name or number (e.g.'january'ordecember)Weekday– Valid weekday name (e.g.'monday')Year– Valid four-digit year (e.g.'2025')
For validating contact and identity formats:
Email– RFC-compliant email address (e.g.'user@example.com')PhoneNumber– E.164 formatted phone number (e.g.'+31612345678')
For structured text, numbers, and identifiers:
Text– A valid text string (e.g.'foo','Lorem ipsum dolor sit amet'or'')Integer– Whole number (e.g.42)Float– Decimal number (e.g.3.14)Percentage– Decimal number between 0 and 1 (e.g.0,0.5or1)Url– Valid absolute URL (e.g.'https://example.com')Uuid– RFC 4122 UUID string (e.g.'550e8400-e29b-41d4-a716-446655440000')