toox

TOOlboX

A set of useful utilities, somewhat tested.

Installation

npm install --save-dev toox

or as a git submodule:

git submodule add <full repo url> toox

to update the submodule to the latest version (git submodule update doesn't do it)

cd toox
git pull

The Good Bits

const toox = require('toox')

range(a, [b], [n]) - a Python style range function

> toox.range(50,85,5)
[ 50, 55, 60, 65, 70, 75, 80 ]

fill(n, x) - an array of size n, filled with x

> toox.fill(10,'hi')
[ 'hi', 'hi', 'hi', 'hi', 'hi', 'hi', 'hi', 'hi', 'hi', 'hi' ]

ellipses(str, [n=80]) - truncate strings if needed

> toox.ellipses(JSON.stringify(toox.fill(100,'hi')), 40)
'["hi","hi","hi","hi","hi","hi","hi","...'

eachPair(obj, func) - iterate through key/value pairs of plain objects

The returned value from the callback is the new value, unless toox.DELETE or undefined is returned, in which case the k/v pair does not appear in the result

> toox.eachPair({a: 'hello', b: 'world'}, (k, v) => v + ':' + k)
{ a: 'hello:a', b: 'world:b' }

sleep - promisified setTimeout

> toox.sleep(5000).then(() => console.log('hello'))
... some time passes
hello

formatMs - tersely display durations from milliseconds to hours

> toox.formatMs(53)
'53ms'
> toox.formatMs(5300)
'5.30s'
> toox.formatMs(530000)
'8m50'
> toox.formatMs(53000000)
'14h43'

stopwatch suite - measure and report time intervals

> (async () => {
... toox.stopwatch.start('test1')
... await toox.sleep(1500)
... toox.stopwatch.endReport('test1')
... })()
test1  finished  1.51s

shuffle(array) - randomize the order of array elements

> toox.shuffle([1,2,3,4,5])
[ 2, 5, 4, 3, 1 ]

after(ms, value) - a promise that resolves to a given value after a time

> toox.after(5000, 'hello').then(console.log)
... some time passes
hello

asyncAllObjectValues(obj) - like Promise.all but for object values

> toox.asyncAllObjectValues({a: toox.after(1000, 'hello'), b: toox.after(2000, 'world')}).then(console.log)
... some time passes
{ a: 'hello', b: 'world' }

parallelize(arrayOfFunctionsThatReturnPromises, [poolSize=4], [timeout=null], [tries=1])

Run some async functions in parallel, at most poolSize at once. Give each one timeout ms to complete, retry tries times or until no error is thrown.

If a function throws an error more than tries times, the error is returned in the results. This may cause problems if your functions return (not throw) errors.