Version bump and publish Maven+Git project

publish.sh

#!/bin/bash

#
# Version bump and publish this Git+Maven repo.
#
# Usage: ./publish.sh {major|minor|patch}
#
# For example, to bump the version from 1.5.9 to 1.6.0:
#
#     ./publish.sh minor

# Validate command line
if
    [[ $# -ne 1 ]] || \
    ! [[ $1 =~ ^(major|minor|patch)$ ]];
then
    echo "Usage: $0 {major|minor|patch}"
    exit 1
fi

# Ensure we're on the develop branch and up-to-date with origin
git fetch
git checkout develop
git reset --hard origin/develop

# Get the current project's version from its pom.xml
current_version=$(mvn -q -Dexec.executable='echo' -Dexec.args='${project.version}' --non-recursive exec:exec)
current_version_semver=( ${current_version//./ } )

# Extract the major, minor, and patch components from the current version
major="${current_version_semver[0]}"
minor="${current_version_semver[1]}"
patch="${current_version_semver[2]}"

# Validate the current version. (We can't bump it if it's not valid semver.)
if
    [[ ${#current_version_semver[@]} -ne 3 ]] || \
    ! [[ ${major} =~ ^[0-9]+$ ]] || \
    ! [[ ${minor} =~ ^[0-9]+$ ]] || \
    ! [[ ${patch} =~ ^[0-9]+$ ]];
then
	echo "Current version (${current_version}) is not valid semver. Aborting."
	exit 1
fi

case "$1" in
    major)
        new_version="$((major+1)).0.0"
        ;;
    minor)
        new_version="${major}.$((minor+1)).0"
        ;;
    patch)
        new_version="${major}.${minor}.$((patch+1))"
        ;;
    *)
        # If this happens, it's a bug
        echo "Well, this is embarrassing. The command line argument should have already been validated."
        exit 1
esac

# Version bump pom.xml
mvn -q versions:set -DnewVersion=${new_version}

# Commit and tag the version
git add -A
git commit -m "Version ${new_version}"
git tag -a "v${new_version}" -m "Version ${new_version}"

# Merge new version into master
git checkout master
git reset --hard origin/master
git merge develop

# Push everything and go back to develop
git push origin master
git push --tags
git checkout develop
git push

echo "$current_version -> $new_version"

Put this in the root of your Maven project (alongside .git and pom.xml). After you have merged one or more pull requests to develop, run this script to version the latest batch of merged pull requests. This will

• version bump pom.xml
• commit the pom.xml change to develop
• tag develop, using the new version
• merge develop to master
• push develop, master and the new tag to origin