# What Bump?
[](https://circleci.com/gh/sky-uk/what-bump)
`what-bump` is a simple tool that reads the commit history of a git repository,
and uses commit messages to decide what kind of version bump is required.
`what-bump` assumes that commit messages are written according to the
[Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/)
specification, and that your software uses [Semantic Versioning](https://semver.org).
Moreover, if you provide `what-bump` with the current version number of your software,
it will tell you what the next version number has to be.
## Rationale
Plenty of tools exist that can read Conventional Commit messages and manage software
releases: see for example the [list](https://www.conventionalcommits.org/en/v1.0.0/#tooling-for-conventional-commits)
in the conventional commit website, as well as [calcver](https://github.com/sanisoclem/calcver-cli).
However, most of those tools are deeply integrated with NPM, or somehow assume that you're
using NPM, try to manage the entire release process of your software, and are not trivial
to set up (especially if you're not using NPM!).
The only tool I could find that does not integrate with NPM is `calcver`, but it is very
young, very undocumented, and probably more powerful and/or complex than I need a tool
to be.
This tool, `what-bump`, sets out to be a simple, self-explanatory, zero-configuration
utility to do one and only one thing: determine your software's next version number
based on all the commit messages up to a previous revision. You need to specify what
the previous revision is (we assume you have it tagged and know enough `bash` magic to
do it) and what the current version is (ditto).
## Installation
The easiest way to get `what-bump` is installing it using [cargo](https://doc.rust-lang.org/cargo/getting-started/installation.html),
with the following command:
cargo install what-bump
If you prefer Docker, there is an official image on dockerhub: https://hub.docker.com/r/albx79/what-bump
## Usage
Just type
what-bump --help
To get all the explanation you need.
Basically, assuming you tagged your previous version as `v1.0.2`, just type
what-bump v1.0.2 --from 1.0.2
to get the next version number printed to standard output.
## Compliance
`what-bump` is a little bit more accepting than Conventional Commits specifies.
In particular, it only checks that the commit type **starts** with "fix" or "feat"
(case insensitive), therefore it will also accept things like "feature", "fixed", or
"fixing".
Also, any other commit type, or commits that don't comply with the spec,
will be ignored and won't contribute to a version bump.
## Build
### With Cargo
`what-bump` is written in [Rust](https://www.rust-lang.org). You'll need at least version
1.36 to build (that's what I used). Install rust following the instructions on the official
website.
It depends on [git2-rs](https://github.com/alexcrichton/git2-rs), which requires
libgit2 to be installed on your system. It should already be available if you're using git.
To build from sources, clone the repository and build with:
cargo build --release
Then you can install it locally with
cargo install --path .
### With Docker
Alternatively, if you have docker, you can build `what-bump` using
the Dockerfile provided:
docker build . -t what-bump
And then run it with e.g.:
docker run -v $PWD:/data what-bump --path /data --help