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    TypeScript-first deep equivalence comparison between two values

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    Equivalent comparison of Object data structures. It supports many built-in objects and can be compared with Date, Array or Object.

    The supported built-in objects are here.

    It provides equal functions and specific data types functions . The equal function works correctly in all situations. The specific data types functions works correctly only for specific data types, but it has good performance. Please check bundle size optimization for details.

    🔖 Table of Contents


    • Multi runtime support (Deno, Node.js and Browsers)
    • 📚 Pure TypeScript and provides type definition
    • Rambda's all test case is passed
    • 🌎 Universal module, providing ES modules and Commonjs
    • 📦 Optimized, super slim size
    • 📄 TSDoc-style comments

    Package name

    Deno: equal (,

    Node.js: lauqe (npm)



    equal("", ""); // true
    equal(NaN, NaN); // true
    equal(0, 0); // true
    equal(+0, 0); // true
    equal(-0, 0); // true
    equal(+0, -0); // true
    equal(0n, 0n); // true
    equal(undefined, undefined); // true
    equal(null, null); // true
    equal(undefined, null); // false
    equal(true, false); // false
    const symbol = Symbol("hello");
    equal(symbol, symbol); // true
    equal(Symbol("hello"), Symbol("hello")); // false


    equal({}, {}) // true
    equal({ "": undefined }, { "": undefined }) // true
    equal({ "": undefined }, { "": undefined, a: 1 }) // false
    equal({ a: 1, b: undefined}, { b: undefined, a: 1}) // true
    equal([], []) // true
    equal([[[]]], [[[]]]) // true
    equal(new Date("2000/1/1"), new Date("2000/1/1")) // true
    equal(() => true, () => true) // true
    equal(AggregateError([ Error("error"), TypeError("type error") ]), AggregateError([ Error("error"), TypeError("type error") ])) // true
    equal(/s/, /s/) // true
    equal(new String('hello'), new String('hello')) // true
    equal(new Number(0), new Number(0)) // true
    equal(new Boolean(true), new Boolean(true)) // true
    equal(new Map([[1, 2], [3, 4]]), new Map([[3, 4], [1, 2]]) // true

    💫 Usage

    equal provides multi platform modules.

    🦕 Deno

    import { equal } from "";
    equal([1, 2, 3], [1, 2, 3]); // true

    import { equal } from "";
    equal([1, ['hello', ['world']], [1, ['hello', ['world']]); // true

    📦 Node.js

    NPM package name is lauqe .


    npm i lauqe
    yarn add lauqe

    ES modules

    import { equal } from "lauqe";
    equal(new Date("2000/1/1"), new Date("2000/1/1")); // true


    const { equal } = require("lauqe");
    equal(/hello/g, /hello/g); // true

    🌐 Browser

    The module that bundles the dependencies is obtained from skypack.

    <script type="module">
      import { equal } from "";
      console.log(equal(() => {}, () => {}); // true

    📝 API

    Definition of Equality

    Equality is defined as the data structure and property values are equivalent.


    Numerical equivalence is based on Same-value-zero.
    That is, all of the following comparisons are considered equivalent.

    equal(NaN, NaN); // true
    equal(0, 0); // true
    equal(+0, 0); // true
    equal(-0, 0); // true
    equal(+0, -0); // true

    Built-in objects

    The following objects work correctly.

    Do not guarantee the behavior of objects not on this list.

    Bundle size optimization

    The equal function works correctly for all supported built-in objects. The price is an increase in bundle size.

    If the data to be compared for equivalence is of multiple data types, or if the data types are unclear, the equal function may be the best choice.

    If the data type is predetermined, you can reduce the bundle size by using the specific function instead.

    Type definition


    Compare the equivalence of the all supported built-in objects and primitive values .

    declare const equal: <T, U extends T>(a: T, b: U) => boolean;
    Parameter Description
    a Any value
    b Any value

    => Return true if the reference memory is the same or the property members and their values are the same


    Compare the equivalence of Date objects.

    declare const equalDate: (a: Date, b: Date) => boolean;
    equalDate(new Date(0), new Date(0)) // true
    equalDate(new Date(0), new Date(1)) // false
    equalDate(new Date("1999/1/1 00:00:01"), new Date("1999/1/1")) // false
    // invalid date
    [new Date("a"), new Date("a"), true],
    [new Date("a"), new Date("b"), true],


    Compare the equivalence of Primitive values.

    declare const equalPrimitive: <T extends Primitive, U extends T>(
      a: T,
      b: U,
    ) => boolean;
    type Primitive =
      | string
      | number
      | bigint
      | boolean
      | symbol
      | undefined
      | null;
    equalPrimitive(NaN, NaN); // true
    equalPrimitive(0, +0); // true
    equalPrimitive(-0, +0); // true


    Compare the equivalence of the Error object and its Derived object.

    declare const equalError: (a: Error, b: Error) => boolean;
    equalError(Error("test"), Error("test")); // true
    ); // true
    equalError(Error("test"), Error("hello")); // false
    equalError(Error("test"), TypeError("test")); // false


    Compare the equivalence of URL objects.

    declare const equalURL: (a: URL, b: URL) => boolean;
    equalURL(new URL("", "")); // true
    equalURL(new URL("", "")); // true


    Compare the equivalence of ArrayBuffer objects.

    declare const equalArrayBuffer: (a: ArrayBuffer, b: ArrayBuffer) => boolean;


    equalArrayBuffer(new ArrayBuffer(0), new ArrayBuffer(0)); // true
    equalArrayBuffer(new ArrayBuffer(0), new ArrayBuffer(1)); // false

    💚 Supports

    ie is no longer supported to reduce bundle size.

    The TypeScript version must be 4.1.0 or higher.

    This project provides ES modules and Commonjs.

    If you have an opinion about what to support, you can open an issue to discuss it.

    The browserslist has the following settings.

    last 8 version
    not IE <= 11
    not ie_mob <= 11
    node 6
    DenoDeno Node.jsNode.js IE / EdgeEdge FirefoxFirefox ChromeChrome SafariSafari iOS SafariiOS Safari SamsungSamsung OperaOpera
    ^1.6.0 ^6.17.0 ^83 ^78 ^83 ^11 ^12.0 ^7.2 ^68

    🤝 Contributing

    Contributions, issues and feature requests are welcome!
    Feel free to check issues.

    Contributing guide

    🌱 Show your support

    Give a ⭐️ if this project helped you!

    💡 License

    Copyright © 2021-present TomokiMiyauci.

    Released under the MIT license


    npm i lauqe

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