# Change Files

There are very popular and excellent packages available which manage package versioning already. Beachball works differently: beachball does _not_ rely on commit messages for determining the next semantic version. Rather, it uses something called a "change file".

# What is a Change File?

After you have made some commits, you are ready to create a change file. A change file is generated for you by beachball. beachball uses the change file to determine how to bump versions in your package.

To generate a change file, you run this command:

$ beachball change # could leave out "change" command since it is the default

It will ask you to put in a description and a change type. Don't worry though, beachball is nice and will find recent commit messages if you would rather describe your changes based on something you already typed! The type of change you specify will influence how beachball will bump your version.

After you've answered those questions, a change file is created and commited in your branch under /change that looks like this:

  "comment": "Upgrading React to 16.8.x to use hooks",
  "type": "minor",
  "packageName": "my-amazing-app",
  "email": "me@me.me",
  "commit": "b785112c03f063b71d936ff052470817019267d4",
  "date": "2019-06-20T22:54:59.172Z"

If you have some existing change file for this package, beachball will assume you're still working on the same feature and will skip the dialog.

# Working with the change file

beachball uses change files to indicate change type for a very good reason. File diffs work wonderfully well in all PR systems. These tools are well suited to visualize file diffs and allows a chance for reviewers to review what is written in a change file.

For example, a reviewer might remind the author that a certain new API has been introduced and that the change ought to be a minor. The author can then modify the change file without having to ammend history of a commit!