kinda-equal

Equality checking for messy models

TL;DR

import kindaEqual from 'kinda-equal';

// Default with default filters applied;
const defaultEqual = kindaEqual();

// No filters; standard deep equality object checker;
const noFilerEqual = kindaEqual({filters: []})

// Filters default with custom;
const customFilterEqual = kindaEqual({filters: [
        kindaEqual.ignoreEmptyArray,
        kindaEqual.ignoreEmptyNullUndefined,
        kindaEqual.ignoreEmptyObject,
        (value, key, index) => key.startsWith('$')
]})


let result1 = defaultEqual(obj1, obj2);
let result2 = noFilerEqual(obj1, obj2);
let result3 = customFilterEqual(obj1, obj2);

About

Allows deep equality checks between 2 objects ignoring insignificant properties.

Properties are ignored for comparison if they match filter functions. 3 filter functions are applied by default (but can be overridden)

• ignoreEmptyNullUndefined
• ignoreEmptyArray
• ignoreEmptyObject

Collectively They remove all values that are null, undefined,'', [], {}

The filters are applied in a depth first scan so:

{
    id: 99,
    items: [{name: {log: [], prive: null}, {name: undefined}]
}

is equivelent to :

{
    id: 99
}

filters are simple functions returning true if the property must be ignored.

They recieve 4 parameters value, key, index, path

Param	Type
value	*
key	string
index	number	Optional if value is Array
path	string	String path from root to the current property e.g 'person.contact.phone[1]'

Example filters

function compareFirstPersonFilter(value, key, index) {
    if (index !== undefined && key === 'people') {
        return index > 0;
    }
}

function ignoreAngular(value, key) {
    return key.startsWith('$');
}

which filters to apply is set in the config object, if supplied they override the default filters.

If you would like to apply any of the defaults with your filter you need to include them.

{
    filters: []
}

Installing

Install with: npm install kinda-equal --save

3 modules builds are provided

• index (commonjs)
• kinda-equal.es (es6)
• kinda-equal.umd (umd)

Usage

Comparing objects with the default ingore filters

const pure = {
    person: {
        first: 'Bob',
        phone: ['555-666', '444-333'],
    },
    transactions: [
        { id: 1, stamp: new Date(2017, 01, 01), log: {} }
    ]
};

const dirty = {
    person: {
        first: 'Bob',
        surname: undefined,
        phone: ['555-666', '444-333', null],
        address: {
            street: null,
            number: null
        }
    },
    transactions: [
        { id: 1, stamp: new Date(2017, 01, 01), log: {} },
        { log: {} }
    ]
};

const result = kindaEqual()(pure, dirty);
assert.equal(true, result);

Adding a custom ignore function including the default ignore functions

const pure = {
    person: {
        first: 'Bob',
        phone: ['555-666', '444-333'],
    },
    transactions: [
        { id: 1, stamp: new Date(2017, 01, 01), log: {} }
    ]
};

// use the default ignore functions and all properties starting with $
const dirty = {
    person: {
        first: 'Bob',
        $idKey: 88,
        surname: undefined,
        phone: ['555-666', '444-333', null],
        address: {
            street: null,
            number: null
        }
    },
    transactions: [
        { id: 1, stamp: new Date(2017, 01, 01), log: {}, $someOtherId: 99 },
        { log: {} }
    ]
};

const config = {
    filters: [
        kindaEqual.ignoreEmptyArray,
        kindaEqual.ignoreEmptyNullUndefined,
        kindaEqual.ignoreEmptyObject,
        (value, key, index) => key.startsWith('$')
    ]
};

const customEqual = kindaEqual(config);
const result = customEqual(pure, dirty);
assert.equal(true, result);

Adding a custom ignore function which uses path

// ignore all but the first (index 0) phone number
const bob_record_1 = {
    person: {
        first: 'Bob',
        contact: {
            phone: ['555-666', '444-333']
        }
    }
};

const bob_record_2 = {
    person: {
        first: 'Bob',
        contact: {
            phone: ['555-666', '699-333']
        }
    }
};

const config = {
    filters: [
        kindaEqual.ignoreEmptyArray,
        kindaEqual.ignoreEmptyNullUndefined,
        kindaEqual.ignoreEmptyObject,
        (value, key, index, path) => path.startsWith('person.contact.phone') && index > 0
    ]
};

const customEqual = kindaEqual(config);
const result = customEqual(bob_record_1, bob_record_2);
assert.equal(true, result);

Dependencies

Developer instructions

npm run test
npm run build

License

MIT