larvitutils

larvitutils

Misc utilities

Loading of library

The library takes one parameter as option, "log". It is designed to take an instance of winston, but more exactly it should be an object with the methods "silly", "debug", "verbose", "info", "warn" and "error". An example of this can be found in the VERY simplified logging utility built in to this library. See documentation below.

Example of loading the library with no configured logger (using the default):

const lUtils = new (require('larvitutils'))();

Example of loading the library with an instance of winston as logger:

const winston = require('winston');
const log = winston.createLogger({'transports':[new winston.transprots.Console()]});
const lUtils = new (require('larvitutils'))({log: log});

Async setTimeout

const lUtils = new (require('larvitutils'))();
await lUtils.setTimeout(1000);
console.log('1000ms later');

Convert a buffer to an Uuid

const lUtils = new (require('larvitutils'))();
const uuid = lUtils.formatUuid(new Buffer('f9684592b24542fa88c69f16b9236ac3', 'hex'));

console.log(uuid); // f9684592-b245-42fa-88c6-9f16b9236ac3

Example usecase: fetch a binary column from a database and convert to a readable Uuid string

Format a hex string to uuid

const lUtils = new (require('larvitutils'))();
const uuid = lUtils.formatUuid(' f9684592b24542fa88c69f16b9236ac3'); // Notice the starting space getting trimmed away

console.log(uuid); // f9684592-b245-42fa-88c6-9f16b9236ac3

hrtimeToMs()

Used to convert hrtime() calls to milliseconds, since hrtime() output is messy (seconrds + nanoseconrds)

Usage:

const lUtils = new (require('larvitutils'))();
const startTime = process.hrtime();

setTimeout(function() {
	console.log('benchmark took %d ms', lUtils.hrtimeToMs(startTime, 4));
 // benchmark took 34.0005 ms
}, 34);

Uuid string to buffer

const lUtils = new (require('larvitutils'))();
const uuidStr = 'f9684592-b245-42fa-88c6-9f16b9236ac3';

lUtils.uuidToBuffer(uuidStr); // Will return a buffer or false on failure

Replace all for strings

const lUtils = new (require('larvitutils'))();
const str = 'f9684592-b245-42fa-88c6-9f16b9236ac3';

lUtils.replaceAll('-', '_', str); // f9684592_b245_42fa_88c6_9f16b9236ac3

Validate an uuid string

const lUtils = new (require('larvitutils'))();
const validUuid = 'f9684592-b245-42fa-88c6-9f16b9236ac3';
const invalidUuid1 = false;
const invalidUuid2 = 'foobar';
const invalidUuid3 = {höhö: 'oveboll'};

lUtils.formatUuid(validUuid); // true
lUtils.formatUuid(invalidUuid1); // false
lUtils.formatUuid(invalidUuid2); // false
lUtils.formatUuid(invalidUuid3); // false

Check if input is an int

const lUtils = new (require('larvitutils'))();

lUtils.isInt(10); // true
lUtils.isInt(10.0); // true
lUtils.isInt(10.5); // false
lUtils.isInt('oveboll'); // false

Simple logger

This is ment as a very simple replacement for winston

const lUtils = new (require('larvitutils'))();
const log = new lUtils.Log();

log.info('Hello'); // prints to stdout "2018-08-08T20:02:34Z [inf] Hello
log.error('Hello'); // prints to stderr "2018-08-08T20:02:48Z [err] Hello

By default only info, warn and error are printed to screen. Set minimum level by string, like this:

const lUtils = new (require('larvitutils'))();
const log = new lUtils.Log('debug');

log.debug('Hello'); // prints to stdout "2018-08-08T20:02:34Z [deb] Debug

Or disable output entirely

const lUtils = new (require('larvitutils'))();
const log = new lUtils.Log('none');

log.error('Hello'); // prints nothing

The default log level can be changed by setting environment variable NODE_LOG_LVL

All logging methods: silly, debug, verbose, info, warn and error.