docdiff

Simple tool for diff'ing two documents (objects)

Example

var docdiff = require('docdiff');

var original = {
  a: 1
};

var now = {
  a: 2
};

var diff = docdiff(original, now);

// diff:
//
// [
//   {
//     path: ['a'],
//     change: 'update',
//     type: 'primitive',
//     values: {
//       now: 2,
//       original: 1
//     }
//   }
// ]

See tests for more examples

Spec

docdiff will return an array of changes, each change will comprise of the following:

path [array] An array of object keys that lead to the value described in this change, for example the changed value at { a: { b: 2 } } would have the path [a, b]
change [string] One of: add, update or remove
type [string] One of primitive, primitiveArray (array of primitives), documentArray (array of objects) or mixedArray
values [object]:
now [mixed] The new value (undefined for type remove)
original [mixed] The original value (undefined for type add)
added [array] Array of elements added (undefined for anything other than primitiveArray)
removed [array] Array of elements removed (undefined for anything other than primitiveArray)

Notes on Arrays

Diffing arrays is hard because there is no universal way of identifing which value in the new array corresponds to which value in the original array (positions may have changed). Subsequently, docdiff is currently naive to changes in arrays that contain anything other than primitives. If the changed array contains ONLY primitives, the type will be primitiveArray and the values object will contain both added and removed for further inspection. However, if an array contains only objects, docdiff will simply return the current and original arrays. You may add you're own post processing of this, for example if you're documents inside the array had id's, you will be able to identify changes properly (pass before and after back to docdiff). the mixedArray type will be used when the array contains neither objects or primitves exclusively.

Author

Thom Seddon

License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.