Pomeranian Durations

An immutable duration library based on the ISO-8601 format for durations.

Basic Usage

Pomeranian durations provides a couple of helpers to work with ISO8601 durations.

  addMinutes('PT3M', 2) // => 'PT5M'
  floorMinutes('PT3.5M') // => 'PT3M'
  findMinutes('PT3M') // => 3

  isValid('P3Y6M1W4DT12H30M17.5S') // => true
  isValid('P3') // => false

A full list of all helpers can be found at the docs

Handling parsing errors

By default this library returns 'Invalid Duration' when it can't parse the format. As every application wants to handle those kinds of errors differently developers can use functional composition to create their own verison of pomeranian durations.

const errorHandler = () => 'An error occured, our team is already on it.'
const addSchoolHour = pipe(
  addHours(1.5),
  whenInvalid(errorHandler)
);

addSchoolHour('PT1H') // => PT2.5H
addSchoolHour('Invalid duration') // => 'An error occured, our team is already on it.'

Upgrade to version 1.0.0

• Swapped arguments of add* and subtract* functions, as they're now curried.

// version 0.*
addSeconds('PT1S', 1) // => PT2S

// version 1.*
addSeconds(1, 'PT1S') // => PT2S
addSeconds(1)('PT1S') // => PT2S

• Wrapper got removed (please use regular functional composition instead)
• Pomeranian durations return 'Invalid Duration' when it receives an invalid duration. It's up to the developer how this should be handled. This library provides a helper whenInvalid which can be used to handle those cases.

import { addSeconds as _addSeconds, whenInvalid } from 'pomeranian-durations';

const addSeconds1 = pipe(
  whenInvalid(() => 'PT0S'),
  _addSeconds(10),
); // => PT10S

const addSeconds2 = pipe(
  _addSeconds(10),
  whenInvalid(() => 'PT0S'),
); // => PT0S

Precision Issues

Because date components (years, months, weeks, days) can't be converted to other unites without date and timezone information, pomeranian-durations doesn't support them yet. To do precise arithmetic operations it is recommended to avoid years, months, weeks and days completely when using durations.

For more information have a look at http://www.ostyn.com/standards/scorm/samples/ISOTimeForSCORM.htm