sleepydogs

Sleepy patterns for Javascript

What is this package?

This package is a collection of modules that offer opinionated abstractions over common patterns encountered in node.js development and web development.

Installation

npm install sleepydogs

pnpm add sleepydogs

yarn add sleepydogs

Usage

sleepydogs module collection is largely going to be divided into two sections: Functional Programming paradigms and Object Oriented Programming paradigms. These will be denoted as fp and oop.

fp: guard

Intended Usage: Reduce boilerplate around exception handling.

import { readFileSync } from 'node:fs';
import { guard } from 'sleepydogs';

/** Wrap a function that might fail in safewrap */
const safeReadFile = guard(readFileSync);

/**
 * data contains file contents if it exists
 * error contains any errors thrown during execution
 **/
const { data, error } = safeReadFile('hello.txt');

fp: logFactory

Intended Usage: Simple, very tiny color console logger. Proxy to console object.

import { Log } from 'sleepydogs';

const logger = Log.factory({
    service: 'my-service',
    level: 'info'
});

oop: Attempt

Intended Usage: Reduce boilerplate around exception handling void | Promise<void> functions

import { Attempt } from 'sleepydogs';

/** Sync example */

function writesFile() { /** Might throw an error */ }

const $writeFileAttempt = new Attempt(writesFile); /** writesFile not called yet */
$writeFileAttempt.runSync(); /** writesFile called here */

/** Advanced Configuration */

function writesFile2() {}
function handleWritesFile2Err() {} /** Handling an error */
const invokeImmediate = true; /** Invoke the callback on instance creation, so there's no need to call runSync */
const retryNum = 5; /** Set up retry logic up to N attempts */

const $writeFileAttempt2 = new Attempt(writesFile2, handleWritesFile2Err, invokeImmediate, retryNum);

/** Peek into the state of the callback */
const { state: cbState } = $writeFileAttempt2;

/** Async Example */

async function readEndpoint () {}

const $readEndpointAttempt = new Attempt(readEndpoint);
await $readEndpointAttempt.run();

oop: Option

Intended Usage: Intended Usage: Reduce boilerplate around functions that may or may not throw an error in the process of returning a value, or simply may or may not return a value. Has opt-in caching. Leans on the Rust concept of Options.

import { Option, OptionCache } from 'sleepydogs';

function fetchesDataSync() {}

const $fetchesDataSyncOption = new Option(fetchDataSync);
const { data, error } = $fetchesDataSyncOption.resolveSync();

// ... 

const cache = new OptionCache();
const cacheConfig = {
    optionCache: cache,
    indexingKey: 'mef-1',
    stale: 3600 // Time in ms before flushing value
};

const myExpensiveFn = () => { /** ... */ };

const $myExpensiveFnOption = new Option(myExpensiveFn, cacheConfig);

const { data, error } = $myExpensiveFnOption.resolveSync(); /** Cached value set here */
const _ = $myExpensiveFnOption.resolveSync(); /** Cached value used here */

/** Reusing a cache across options */

const cacheConfig2 = {
    optionCache: cache,
    indexingKey: 'mef-2',
};

function myExpensiveFn2() {}
const $mefOption2 = new Option(myExpensiveFn2, cacheConfig2);

/** Getting the value through match */

function anotherFn() {}
new Option(anotherFn)
    .resolveSync()
    .match(
        (value) => { /** Handle value */},
        (err) => { /** Handle error */ }
    );

oop: Signal

Intended Usage: Simple Signal Based State Management, see TC39 A Proposal To Add Signals To Javascript

import { Signal } from 'sleepydogs';

const stateSignal = new Signal.State(22);
const computedIsEvenSignal = new Signal.Computed(() => (stateSignal.get() % 2) === 0);

oop: LazySingleton

Intended Usage: Lazy singleton class instantiation and management

import { LazySingleton } from 'sleepydogs';

class MySingletonClass { /** Class Implementation */ }
const MySingletonClassProvider = LazySingleton(MySingletonClass); /** Class has not been instantiated yet */
const instanceA = MySingletonClassProvider.getInstance(); /** Class is instantiated here */
const instanceB = MySingletonClassProvider.getInstance(); /** Singleton instance used here */

console.log(Object.is(instanceA, instanceB)); // true