README
var-diff
get the difference between two variables
Compatibility
IE | Chrome | Firefox | Opera | Safari |
---|---|---|---|---|
✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
### Installation |
npm i var-diff
or
<script src="var-diff.js"></script>
Usage
use var patches = diff.get(origin, target, [key])
to get difference patches
between origin and target variables.
key
is an optional parameter used to improve sorting performance.
patches
is an array containing all of the differences betwen two variables
// patches
t: type 1-create 2-delete 3-edit 4-replace
p: path {Array}
v: value
i: new index(when type is replace)
use diff.apply(origin, patches)
to make the origin variable apply the patches
then become the target varible. but all references of the origin variable are reserved.
const diff = require('var-diff');
let a = [1, 2, 3, {id: 1, name: 'tom'}, {id: 2, name: 'jack'}]
let b = [2, {id: 2, name: 'will'}, 3, {id: 1, name: 'lucy'}]
let patches = diff.get(origin, target, 'id');
console.log(patches);
/**
* patches
[
{ t: 2, p: [ 0 ] }, // remove the 0th element
{ t: 3, p: [ 2, 'name' ], v: 'lucy' }, // update the name of the 2th element to 'lucy'
{ t: 3, p: [ 3, 'name' ], v: 'will' }, // update the name of the 3th element to 'will'
{ t: 4, p: [ 3 ], i: 1 }, // change the 3th element to the 1th position
{ t: 4, p: [ 3 ], i: 2 } // change the 3th element to the 2th position
]
*/
a = diff.apply(a, patches);
console.log(JSON.stringify(a) === JSON.stringify(b));
// true
Examples
var a = {
name: 'tom',
gender: 'male',
list: [{
id: 1,
label: 'teacher'
}]
}
var b = {
name: 'jack',
list: [{
id: 2,
label: 'worker'
}, {
id: 3,
label: 'student'
}, {
id: 1,
label: ''
}]
}
p = diff.get(a, b, 'id');
console.log(p);
/**
t: type 1-create 2-delete 3-edit 4-replace
p: path {Array}
v: value
i: new index(when type is replace)
[{ t: 3, p: [ 'name' ], v: 'jack' },
{ t: 2, p: [ 'gender' ] },
{ t: 3, p: [ 'list', 0, 'label' ], v: '' },
{ t: 1, p: [ 'list', 1 ], v: { id: 2, label: 'worker' } },
{ t: 1, p: [ 'list', 2 ], v: { id: 3, label: 'student' } },
{ t: 4, p: [ 'list', 0 ], i: 2 },
{ t: 4, p: [ 'list', 1 ], i: 0 },
{ t: 1, p: [ 'age' ], v: 25 }]
*/
var aa = diff.apply(a, p, 'id'); // key
console.log(JSON.stringify(aa) === JSON.stringify(b)); // true
var a = [NaN, NaN];
var b = [NaN, NaN];
var p = diff.get(a, b, 'id');
console.log(p); // []
LICENSE
MIT