deep-reduce-object

Performs a deep reduce on complex nested objects and arrays

Install

npm i deep-reduce-object

const deepReduce = require('deep-reduce-object')

// Complex nested objects
const complexNestedObject = {
    transactions: [
        { 
            id: 1,
            amounts: [
                { value: 10 },
                { value: 20 },
            ]
        },
        { 
            id: 2,
            // amounts: undefined
        },
        { 
            id: 3,
            amounts: [
                { value: 30 },
                { value: 40 },
            ]
        }
    ]
}

// Get the sum of all values
const initialValue = 0
const reducer = (a, b) => a + b)
const path = 'transactions.amounts.value'
const sum = deepReduce(complexNestedObject, reducer, initialValue, path)
// sum = 100

API

deepReduce takes 5 arguments. 4 mandatory and 1 optional:

deepReduce (
    collection: object|array,
    reducer: (accumulator: any, currentValue: any) => any,
    initialValue: any
    path: string,
    context: any
): any

Arguments

• collection Object or Array to traverse.
• reducer Function to call with every value in obj-tree. See section below for reducer function signature.
• initialValue Initial value of reduced passed to reducer.
• path Path to the inner property of collection to be reduced.
• context (optional) Bound to reducer as this.

Arguments for reducer function

The reducer function is called with these arguments:

(accumulator: any, value: any) => any

• accumulator The accumulated value returned by the reducer
• value Value of current path.

Development

git clone https://github.com/eltonbor/deep-reduce-object.git
cd deep-reduce-object
npm install
npm test  # runs node index.test.js

Inspired on

https://github.com/kmalakoff/reduce-deep

License

MIT © 2022 Elton Tasca Borssoi