jsBuddy

Provides modelUpdate() helper function to easily update an ARRAY or OBJECT without mutating the existing array/object and easily update deep nested objects without having to spread the objects at each level.

npm i jsbuddy -S

modelUpdate

modelUpdate(source, model, variables)

source is the existing object

model is the object with changes you would like to make

variables is the object which contains any variables used in the model

Object Example:

import {modelUpdate} from 'jsbuddy';
const source = {
    name: 'Sum User',
    age: 24,
    hobbies: {
        chess: true,
        sudoku: false,
        badminton: true
    }
};

const updatedSource = modelUpdate(source, {
    name: {
        $set: 'Some User'
    },
    hobbies: {
        $merge: {
            sudoku: true,
            cricket: true
        },
        $unset: ['badminton']
    }
});

Output:

{
    name: 'Some User',
    age: 24,
    hobbies: {
        chess: true,
        sudoku: true,
        cricket: true
    }
}

Array Example:

const source = [
    { id: 2 },
    { id: 3}
];

const updatedSource = modelUpdate(source, {
    $push: [
        { id: 4 },
        { id: 5 }
    ],
    // Don't have to use an array when there is only 1 item
    $unshift: { id: 1 },
    $remove: [1] // Removes 1st item {id: 2}
});

Output:

    [ { id: 1 }, { id: 3 }, { id: 4 }, { id: 5 } ]

Array Operations

Operation	Values (refer to examples)
$set	Any	Replaces current value with passed value in the model
$push	[items] or item	Adds the passed items or item to the end of an array
$unshift	same as $push	Adds the passed items or item to the beginning of an array
$remove	[array indices], {key: value}, {key: function() { }} function must return bool.	Removes the items which
$splice	[startIndex, endIndex, item1]	Remove items and/or new items to array

Object Operations

Operation	Values (refer to examples)
$set	Any	Replaces current value with passed value in the model
$unset	[keys] or "key"	Removes specified keys from the object
$merge	{newKey: newValue}	Add new properties to the existing object

Examples

// General Example
const source = {
    store1: {
        products: [{
            id: 'p1'
        }]
    },
    store2: {
        products: [{
            id: 'p4'
        }]
    }
};

modelUpdate(source, {
    store1: {
        products: {
            $push: [{id: 'p2'}, {id: 'p3'}]
        }
    },
    store2: {
        products: {
            'p4': {
                $merge: {
                    name: 'Product 4'
                }
            }
        }
    }
});

// Example Array:
const source = [{ id: 1 }];

// $set examples
modelUpdate(source, {
    0: {
        $set: { id: 'one' }
    }
});

modelUpdate(source, {
    $1: {
        $set: { id: 'one' }
    }
}, {
    $1: function(item, index) {
        return index === 0;
    }
});

// $push or $unshift examples
modelUpdate(source, {
   $push: [{ id: 2 }]
   // or
   $push: { id: 3 }
});

// $remove
modelUpdate(source, {
    $remove: 0,
    // or 
    $remove: [0, 1],
    // or 
    $remove: {       // Removes item with matching object value
        id: 2
    },
    // or
    $remove: function(item, index) {  // Removes Array Item Matching object value
        retrun index === 0;
    },
    // or
    $remove: 'randomId123' // Remove array item object with key id / _id as randomId123
})

// $splice
modelUpdate(source, {
    $splice: [0, 10]    // Removes 10 items from 0
    // or
    $splice: [
        // Removes 1 item and adds 1 item
        [0, 1, {id: 3}], 
        // Removes nothing but adds 2 items
        [1, 0, {id: 4}, {id: 5}] 
    ]
})

// $merge
modelUpdate(source, {
    0: {
        $merge: {
            newId: 'SOME VALUE'
        }
    },
    // or
    '*': { // This will apply to all array items
        $merge: function(item, index) {
            return {
                newId: item.id * 10
            };
        }
    }
});

// $unset
modelUpdate(source, {
    '*': {
        $unset: 'id'
    }
    '*': {
        $unset: function(key, value) {
            return key === 'id';
        }
    }
});