yaml diff Examples

1. Introduction
2. Synchronizing Array Elements
   1. Order-Centric Element Comparisons
   2. Data-Centric Element Comparisons

Introduction

This page explores various real-world use-cases for the yaml-diff command-line tool.

Synchronizing Array Elements

It is sometimes more informative to compare Arrays by the distinctiveness of their elements rather than the order of them. Consider the following differences.

File: lhs.yaml

---
- alpha
- mu
- psi
- beta
- delta
- chi
- delta
- gamma
- alpha

File: rhs.yaml

---
- zeta
- mu
- psi
- alpha
- gamma
- gamma
- phi
- beta
- chi

Order-Centric Element Comparisons

By default, Array element are compared by the order in which they appear. For the sample documents, this produces the following differences:

c [0]
< alpha
---
> zeta

c [3]
< beta
---
> alpha

c [4]
< delta
---
> gamma

c [5]
< chi
---
> gamma

c [6]
< delta
---
> phi

c [7]
< gamma
---
> beta

c [8]
< alpha
---
> chi

Data-Centric Element Comparisons

When using the --sync-arrays (-a) option, this output turns very different. Rather than comparing each element, one-by-one in the order they appear within both Arrays, the elements are instead rearranged to match them together as much as possible. Doing so produces this output:

d [4]
< delta

d [6]
< delta

d [8]
< alpha

a [9]
> zeta

a [10]
> gamma

a [11]
> phi

Note once the elements are synchronized, there are actually far fewer differences between the two documents.

This isn't the best option for every use-case. For example, this is counter-useful when the elements are time-based observations or an important sequence of specific actions.