Georgette / eventuate-reduce

create a reduced eventuate

eventuate-reduce

Create a reduced eventuate

example

var eventuate = require('eventuate'),
    reduce    = require('eventuate-reduce')

var pie = eventuate()
pie(function (p) {
    console.log('%s served...', p.type)
})

var eatingEverything = reduce(pie, function (lastValue, pie) {
    return lastValue + ' ' + pie.type
}, 'Pies eaten so far in pie eating contest: ')

eatingEverything(function (pie) {
    console.log(pie)
})

pie.produce({type: 'apple' })
pie.produce({type: 'shoofly' })
pie.produce({type: 'pumpkin' })

eatingEverything.reset('')

pie.produce({type: 'cherry' })
pie.produce({type: 'blueberry' })

console.log('Whew, I barfed but managed to keep these pies in my belly: ', eatingEverything.lastValue)

api

var eventuate = require('eventuate')
var reduce    = require('eventuate-reduce')

var upstreamEventuate = eventuate()

var reducedEventuate = reduce(upstreamEventuate, reduceFunc, [initialValue])

Returns a new eventuate which produces reduced event payloads from eventuate upstreamEventuate using reduceFunc . reduceFunc should have the signature function (lastValue, data) { }, and return the reduced payload. This function receives the lastValue from the last produce and all event data from upstreamEventuate.

If upstreamEventuate is an unmonitored eventuate, filteredEventuate will return an unmonitored eventuate.

Note: initialValue is an optional parameter used to initialize the reduce, and if not provided, the first payload will not perform a reduce or a produce

reducedEventuate.lastValue

Retrieve the last produced value

reducedEventuate.reset(resetValue)

Reset the current summation and last value to value passed in resetValue

reducedEventuate.unsubscribe()

Stop consuming events from upstreamEventuate (and thus stop producing events).

reducedEventuate.upstreamConsumer

The function added as a consumer to the upstreamEventuate. Example:

var consumerIdx = upstreamEventuate.consumers.indexOf(reducedEventuate.upstreamConsumer)
assert(consumerIdx >= 0)

install

With npm do:

npm install eventuate-reduce

testing

npm test [--dot | --spec] [--phantom] [--grep=pattern]

Specifying --dot or --spec will change the output from the default TAP style. Specifying --phantom will cause the tests to run in the headless phantom browser instead of node. Specifying --grep will only run the test files that match the given pattern.

browser test

npm run browser-test

This will run the tests in all browsers (specified in .zuul.yml). Be sure to educate zuul first.

coverage

npm run coverage [--html]

This will output a textual coverage report. Including --html will also open an HTML coverage report in the default browser.