flog

Tiny but mighty log function with zero dependencies, functional style.

Installation

Don't want to set up a build environment? Download flog from unpkg and it will be globally available through the window.flog object. Works in ES5-friendly browsers >=IE9.

<script src="https://unpkg.com/@warwickgrigg/flog"></script>

Usage

Here some examples to get you started.

import { h, patch } from "@warwickgrigg/flog";
// or const { log, toJSON } = require("@warwickgrigg/flog"); // node common js

// log(logger)(transformer)(threshold)(level)(text)(data)

// example arguments

const logger = (text, data) => console.log(text, data); // logger function
const transformer = toJSON; // function: eg. log as tabbed JSON
const threshold = 0; // log every level greater than zero
const level = 1; // very detailed; eg. detailed debug level
const data = ["brave", "new", "world"];

log(console.log)(toJSON)(threshold)(level)("tempest")(data);
// tempest [
//  "brave",
//  "new",
//  "world"
// ]

// functional commposition factory example: logAll

const logAll = log(console.log)(toJSON)(0)(1);
logAll("debug 1")("hello world"); // debug 1 "hello world"

// flog returns data passed in final invocation's data argument -
//   useful for debug logging of promises, functional composition etc
//
// .then(logAll("debug 1"))
// .then(x => lookup(connection, x))
// .then(logAll("debug 2"))
// .then (
//    etc

const x = logAll("debug 3")("hello world"); // debug 3 "hello world"
console.log(x); // hello world

// transformer function defaults to identity function (ie no transformation)

[1, 2, 3, 4, 5, 6, 7, 8, 9].map(i => log(console.log)()(5)(i)("")("i" + i)); // i6 i7 i8 i9

License

flog is MIT licensed. See LICENSE.