campsi-array-diff

Campsi's Array Diff

Diff two arrays and find the closest changes to apply.

Usage

Array diff takes two parameters : prev and next, which have to be of array type The function returns a list of changes. A change is a literal object with two properties, oldIndex and newIndex :

• If oldIndex equals -1, it means that the element wasn't in the prev array, and thus has been added to next.
• If newIndex equals -1, it means that the element isn't in the next array, but was in the prev
• If newIndex equals oldIndex, no change

Example

var prev = ['foo', 'bar', {complex: true, property: 'foobar'}, 42];
var next = ['bar', 'foo', {property: 'foobar', complex: true}, 'ok'];
var diff = require('./index.js');
console.dir(diff(prev, next));

Will output :

 [
 {oldIndex: 0, newIndex: 1},
 {oldIndex: 1, newIndex: 0},
 {oldIndex: 2, newIndex: 2},
 {oldIndex: 3, newIndex: -1},
 {oldIndex: -1, newIndex: 3}
 ] 

Info

This array diff relies on equals, it means it does not check the strict equality when it comes to object or array values inside the arrays.