Pipers

Pipers is a helper library to create function chains, or pipes, that process a value through a series of transformations into its final value. It supports async transformations, and comes with a set of basic transform functions ready to be used. Good TypeScript support is a big goal for the library.

Installation

npm install pipers

yarn add pipers

Usage

const displayName = pipe(
	(value) => value.toLowerCase(),
	(value) => value.replace(/ /g, ""),
	(value) => value.slice(0, 10)
);

const name = displayName("Robert Smith"); // "robertsmit"

Validation

Pipe functions can throw, which will stop the chain, and can be used for data validation.

const name = pipe(
	(value) => {
		if (typeof value !== "string") throw "Name was not a string";
		return value;
	},
	(value) => value.slice(0, 10),
	toCamelCase
);

try {
	const something = name("Something"); // "something"
	const somethingElse = name("Something Else"); // "somethingE"
	const notString = name(10); // throws "Name was not a string"
} catch (e) {
	console.log(e);
}

Async

Pipe functions can also be asynchronous. The pipe will wait for the promise to resolve before continuing with the next transformation.

const asyncPipe = pipe(
	(value) => value.toLowerCase(),
	async (value) => {
		const result = await fetch(`https://example.com/api/${value}`);
		return result.json();
	},
	console.log
);

asyncPipe("Test"); // calls fetch with `https://example.com/api/test`

Built in functions

Some Pipe functions are included with the package, and can optionally be imported. In addition, other libraries like Lodash can be used on conjunction.

import {
	isString,
	toLowerCase,
	stringSlice,
	stringReplace,
} from "pipers/string";
import { camelCase } from "lodash";
import { toJSON } from "pipers/promise";

const displayName = pipe(
	toLowerCase,
	stringReplace(/ /g, ""),
	stringSlice(0, 10)
);
const name = pipe(isString, stingSlice(0, 10), camelCase);
const asyncPipe = pipe(toLowerCase, fetch, toJSON, console.log);

Validators

Boolean

• isBoolean
• isFalsy
• isTruthy

Number

• isNumber
• numberLimit

String

• isString
• stringLimit

Array

• isArray

Object

• isObject

Promise

• isPromise

Transformers

Boolean

• toBoolean
• flip

Number

• numberClamp
• numberRemap

String

• stringify
• toLowerCase
• toUpperCase
• stringSlice
• stringLength
• stringReplace

Array

• map
• filter
• reduce
• sort
• reverse
• slice

Promise

• toJSON

TODO

• Add tests
• More documentation for built-in functions
• JS doc for all functions
• Create logo
• Set up perf testing
• Look for optimization avenues