SCEPTER-utility-lib

A library of useful javascript utility functions

Usage

Add this library to your project via npm or yarn with the command:

npm install -S @source4society/scepter-service-utility-lib

or yarn add @source4society/scepter-service-utility-lib

Then in your code, you can reference the individual utility functions. For example, to export the initiateHandledSequence function:

const initiateHandledSequence = require('@source4society/scepter-service-utility-lib').initiateHandledSequence

Functions

makeSequenceCallback

This is a helper function usually called by some of the other functions in this library. It takes a sequence (generator object) and a "final callback" and returns a callback function that will pass any errors into the "final callback" if errors is not empty while passing anything in data to the generators next() function. Useful for converting a series of steps with callbacks into sequential code for easy testing and debugging.

initiateSequence

This will take a generator object and a callback, create the sequenceCallback for this generator and kick off the generator's initial next call as well as provide a second next call that passes in the sequence callback as an argument so that it can be accessed within the generator (the generator should make arrangements to receive the sequenceCallback with the field yield).

initiateHandledSequence

Similar to initiateSequence except this function wraps the generator function in a sequence handler. The default sequence handler is described below. Takes a sequence generator object and the final callback as arguments

sequenceHandler

This returns a generator function that wraps the original sequence generator in a try catch block so any errors thrown from the sequence will be caught and passed to the error position of the final callback

invokeScepterLambdaService

This function will use the AWS SDK to invoke a Lambda function using the naming conventions according to SCEPTER. The function takes the serviceKey (of the service to invoke in services.json), a payload, the environment stage, the AWS SDK, services, credentials, and parameters json files as immutable objects, and a callback. The function will attempt to extract the region, account, serviceName, and function from the appropriate configuration files before calling invoke.