update package.json version automatically

npm version is probably the correct answer. Just to give an alternative I recommend grunt-bump. It is maintained by one of the guys from angular.js.

Usage:

grunt bump
>> Version bumped to 0.0.2

grunt bump:patch
>> Version bumped to 0.0.3

grunt bump:minor
>> Version bumped to 0.1.0

grunt bump
>> Version bumped to 0.1.1

grunt bump:major
>> Version bumped to 1.0.0

If you're using grunt anyway it might be the simplest solution.

As an addition to npm version you can use the --no-git-tag-version flag if you want a version bump but no tag or a new commit:

npm --no-git-tag-version version patch

https://docs.npmjs.com/cli/version

This is what I normally do with my projects:

npm version patch
git add *;
git commit -m "Commit message"
git push
npm publish

The first line, npm version patch, will increase the patch version by 1 (x.x.1 to x.x.2) in package.json. Then you add all files -- including package.json which at that point has been modified. Then, the usual git commit and git push, and finally npm publish to publish the module.

I hope this makes sense...

Merc.

Right answer

To do so, just npm version patch =)

My old answer

There is no pre-release hook originally in git. At least, man githooks does not show it.

If you're using git-extra (https://github.com/visionmedia/git-extras), for instance, you can use a pre-release hook which is implemented by it, as you can see at https://github.com/visionmedia/git-extras/blob/master/bin/git-release. It is needed only a .git/hook/pre-release.sh executable file which edits your package.json file. Committing, pushing and tagging will be done by the git release command.

If you're not using any extension for git, you can write a shell script (I'll name it git-release.sh) and than you can alias it to git release with something like:

git config --global alias.release '!sh path/to/pre-release.sh $1'

You can, than, use git release 0.4 which will execute path/to/pre-release.sh 0.4. Your script can edit package.json, create the tag and push it to the server.