simple-diff

Lib for simple diff with detection of moved items in array

var oldObject = {
    prop1: 'value1',
    prop2: [
        {
            id: 1,
            name: 'name1'
        },
        {
            id: 2,
            name: 'name2'
        },
        {
            id: 3,
            name: 'name3'
        },
        {
            id: 4,
            name: 'name4'
        }
    ]
};

var newObject = {
    prop1: 'value01',
    prop2: [
        {
            id: 2
        },
        {
            id: 1,
            name: 'name01'
        },
        {
            id: 4,
            name: 'name4'
        },
        {
            id: 5,
            name: 'name5'
        }
    ],
    prop3: 'value3'
};

var changes = diff(oldObject, newObject, {
    idProp: 'id'
});

console.log(changes);

Output

[
    {
        oldPath: ['prop1'],
        newPath: ['prop1'],
        type: 'change',
        oldValue: 'value1',
        newValue: 'value01'
    },
    {
        oldPath: ['prop2'],
        newPath: ['prop2'],
        type: 'remove-item',
        oldIndex: 2,
        curIndex: 2,
        newIndex: -1,
        oldValue: {
            id: 3,
            name: 'name3'
        }
    },
    {
        oldPath: ['prop2'],
        newPath: ['prop2'],
        type: 'add-item',
        oldIndex: -1,
        curIndex: -1,
        newIndex: 3,
        newValue: {
            id: 5, 
            name: 'name5'
        }
    },
    {
        oldPath: ['prop2'],
        newPath: ['prop2'],
        type: 'move-item',
        oldIndex: 1,
        curIndex: 1,
        newIndex: 0
    },
    {
        oldPath: ['prop2', 1, 'name'],
        newPath: ['prop2', 0, 'name'],
        type: 'remove',
        oldValue: 'name2',
        newValue: undefined
    },
    {
        oldPath: ['prop2', 0, 'name'],
        newPath: ['prop2', 1, 'name'],
        type: 'change',
        oldValue: 'name1',
        newValue: 'name01'
    },
    {
        oldPath: ['prop3'],
        newPath: ['prop3'],
        type: 'add',
        oldValue: undefined,
        newValue: 'value3'
    }
]

Installation

npm i simple-diff

bower i simple-diff

Lib will look for CommonJS or AMD or will be added global function called simpleDiff().

Options

idProp: 'id' || '*'

Property name with unique value in it array. Default value is id. If your arrays do not have unique properties then you should set this option as * and lib will compare items one by one without trying to find moved items.

idProps: {'path': 'propName' || '*'}

Hash where key is path to array and value is id property. Path examples: users.list, user.list.1.friends, users.list.*.friends

comparators: [[Class, function (oldValue, newValue, options)], ...]

Array of comparators to handle comparison of objects which do not have own properties. For example instead of user.name you have user.getName() or you need to compare Date objects or you just know quick way to compare large objects like by id property and you do not need full list of changes of those objects. First value of comparator should be some class and second is function which should return true if objects are equal and false if they not. In options will be oldPath and newPath.

var now = new Date();
var prevHour = new Date();
prevHour.setHours(-1);

var changes = diff(
	{
		createdAt: now
	},
	{
		createdAt: prevHour
	},
	{
		comparators: [
			[Date, function(oldValue, newValue, options) {
			    options.oldPath; // ['createdAt']
			    options.newPath; // ['createdAt']
			    
			    return oldValue.toString() === newValue.toString();
			}]
		]
	}
);

ignore: function (oldValue, newValue, options)

Function which will be called before each object comparison and if returning value will be true then objects will be ignored. In options will be oldPath and newPath. Useful to prevent from traversing through circular references and when you don't want to compare some kind of objects at all.

callback: function (event)

Function which will be called for each event. If callback is passed then lib will not create array of all changes.

addEvent: 'add'

Name of event when new property added to object. Default value is add

changeEvent: 'change'

Name of event when property value changed. Default value is change

removeEvent: 'remove'

Name of event when property removed from object. Default value is remove

addItemEvent: 'add-item'

Name of event when new item added to array. Default value is add-item

removeItemEvent: 'remove-item'

Name of event when item removed from array. Default value is remove-item

moveItemEvent: 'move-item'

Name of event when item changed it index in array. Default value is move-item