@100terres/spread

Ergonomic conditional spread.

Why?

Instead of using an if statement with Object.assign.

function buildConfig(host, isSecure) {
  const config = { host, protocol: "http" };

  if (isSecure) {
    Object.assign(config, { ssl: true, protocol: "https" });
  }

  return config;
}

Instead of using a ternary operator wrapped in parentheses, which either returns the object to spread or an empty object literal.

const buildConfig = (host, isSecure) => ({
  host,
  protocol: "http",
  ...(isSecure ? { ssl: true, protocol: "https" } : {}),
});

You can use this easy-to-read utility.

import spread from "@100terres/spread";

const buildConfig = (host, isSecure) => ({
  host,
  protocol: "http",
  ...spread({ ssl: true, protocol: "https" }).if(isSecure),
});

See the usage section for more examples.

Getting Started

Install @100terres/spread using the package manager of your choosing, import it and start using it!

Using npm

npm install @100terres/spread

Using pnpm

pnpm add @100terres/spread

Using yarn

yarn add @100terres/spread

Usage

Overview

Examples	Description
spread(object).if(condition)	Returns object when condition is truthy
spread(object).unless(condition)	Returns object when condition is falsy
spread(array).if(condition)	Returns array when condition is truthy
spread(array).unless(condition)	Returns array when condition is falsy
spread(callback).if(condition)	Returns value from callback when condition is truthy
spread(callback).unless(condition)	Returns value from callback when condition is falsy

Disclaimer

If the condition isn't met the function returns an empty array. Since an empty array can be spread into both objects and arrays, nothing is added in either case.

With if method

It returns the object passed if the condition is truthy.

import spread from "@100terres/spread";

// { foo: "bar", baz: "qux" }
const a = {
  foo: "bar",
  ...spread({ baz: "qux" }).if(true),
};

// { foo: "bar" }
const b = {
  foo: "bar",
  ...spread({ baz: "qux" }).if(false),
};

With unless method

It returns the object passed if the condition is falsy. In this example, we'll use an array, instead of an object.

import spread from "@100terres/spread";

// [ "foo", "bar" ]
const a = ["foo", "bar", ...spread(["baz", "qux"]).unless(true)];

// [ "foo", "bar", "baz", "qux" ]
const a = ["foo", "bar", ...spread(["baz", "qux"]).unless(false)];

With a callback

It conditionally invokes the callback.

import spread from "@100terres/spread";

// It will also log "Hello World!"
// { foo: "bar", baz: "qux" }
const a = {
  foo: "bar",
  ...spread(() => {
    console.log("Hello World!");

    return { baz: "qux" };
  }).if(true),
};

// It won’t log "Hello World!"
// { foo: "bar" }
const b = {
  foo: "bar",
  ...spread(() => {
    console.log("Hello World!");

    return { baz: "qux" };
  }).if(false),
};

JSX example

It can increase the readability of your JSX code.

import spread from "@100terres/spread";

const SubmitButton = (props) => {
  const { isSubmitting } = props;

  return (
    <button
      type="submit"
      disabled={isSubmitting}
      {...spread({ className: "is-loading" }).if(isSubmitting)}
    >
      Submit
    </button>
  );
};

License

Licensed under the MIT license.

Acknowledgements

Mathieu Mazy is the original author of the utility itself.

I've created, published, and maintained @potloc/spready package, but I no longer work at Potloc, and I've lost access to the repo, so I've decided to bring it back to life under @100terres/spread.