Defiant – Tuple and Record Utilities

A small utility module for working with tuples (frozen arrays) and records (frozen objects) in JavaScript / TypeScript.

The module emphasizes immutability and provides helpers for creation, type checks, deep equality, and conversion.

Overview

Version: 1.0.0

Defiant provides:

Immutable tuple creation (Object.freeze();-based)
Immutable record creation (Object.freeze();-based)
Type guards for tuples and records
Deep equality comparison for arrays and objects
Conversion utilities between frozen and mutable structures

The module is implemented in TypeScript-compatible JavaScript and relies only on standard ECMAScript APIs.

Design Notes

Immutability is shallow by design

Freezing is applied only at the top level

No external dependencies
TypeScript-friendly

Uses generics and type predicates

Structural equality

Useful for functional programming and state comparison

Autotest

How to import

Import directly as a local module:

import { Tuple, Record } from "./defiant.js";

Import default directly as a local module:

import { default as defiant } from "./defiant.js";

Import defaultExport directly as a local module:

import { defaultExport as defiant } from "./defiant.js";

Exports

export { Tuple, Record };
export default { Tuple, Record };

Tuple Utilities

Tuples are implemented as frozen arrays.

`Tuple(...values)`

Creates a frozen array (tuple) from the given values.

const t = Tuple(1, "a", true);
// readonly [1, "a", true]

Signature

Tuple<T extends readonly unknown[]>(...values: T): T

`Tuple.of(...values)`

Alias for Tuple(...).

const t = Tuple.of(1, 2, 3);

`Tuple.from(iterable)`

Creates a tuple from an iterable or array-like object.

const t = Tuple.from(new Set([1, 2, 3]));

Signature

Tuple.from<T extends readonly unknown[]>(
  iterable: Iterable<unknown> | ArrayLike<unknown>): T

`Tuple.isTuple(value)`

Checks whether a value is a frozen array.

Tuple.isTuple(Object.freeze([1, 2])); // true
Tuple.isTuple([1, 2]);                // false

Signature

Tuple.isTuple(value: unknown): value is readonly unknown[]

`Tuple.isEqual(x, y)`

Performs a deep equality check between two values.

Characteristics

Uses SameValueZero semantics for primitives

NaN === NaN -> true

-0 and +0 are treated as equal

Recursively compares:

Arrays (length and element order)

Objects (prototype, keys, and values)

Works for nested structures

Tuple.isEqual(
  Tuple(1, { a: 2 }),
  Tuple(1, { a: 2 })
); // true

Signature

Tuple.isEqual<T extends readonly unknown[]>(x: T, y: T): boolean

`Tuple.toArray(value)`

Converts a tuple to a mutable array (shallow copy).

const arr = Tuple.toArray(Tuple(1, 2, 3));

Note: Nested objects are still shared.

Signature

Tuple.toArray<T extends readonly unknown[]>(value: T): unknown[]

Record Utilities

Records are implemented as frozen objects (shallow freeze).

`Record(object)`

Creates a frozen copy of an object.

const r = Record({ a: 1, b: 2 });

Characteristics

Shallow freeze
Nested objects remain mutable

Signature

Record<T extends object>(O: T): T

`Record.fromEntries(entries)`

Creates a record from an iterable of key–value pairs.

const r = Record.fromEntries([
  ["a", 1],
  ["b", 2],
]);

Signature

Record.fromEntries<T extends object>(
  entries: Iterable<readonly [keyof T, unknown]>
): T

`Record.fromObject(object)`

Alias for Record(object).

const r = Record.fromObject({ x: 10 });

`Record.isRecord(value)`

Checks whether a value is a frozen object.

Record.isRecord(Object.freeze({ a: 1 })); // true
Record.isRecord({ a: 1 });                // false

Signature

Record.isRecord(value: unknown): value is object

`Record.isEqual(x, y)`

Alias for Tuple.isEqual.

Record.isEqual({ a: 1 }, { a: 1 }); // true

Signature

Record.isEqual(x: readonly unknown, y: readonly unknown): boolean

`Record.toObject(value)`

Converts a record to a mutable object (shallow copy).

const obj = Record.toObject(Record({ a: 1 }));

Signature

Record.toObject<T extends object>(value: T): object

License

https://opensource.org/licenses/MIT

MIT License

SPDX short identifier: MIT

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.