CI step to check whether a package.json version number has been bumped

check-package-version.txt

#!/bin/bash

# Pull repo name from first argument
repo_name=$1

# Pull the latest release version from NPM
latest_release=$(npm show $repo_name version)
echo "Latest released version" $latest_release

# Pull the version from package.json
package_version=$(node -p "require('./package.json').version")
echo "Current package version" $package_version

# Comma-delimit the versions, translate the commas into newlines,
# sort by version (-V) in reverse order (-r), and return the top result
highest_semver=$(echo "$package_version,$latest_release" | tr ',' '\n' | sort -rV | head -1)

# If the highest version is the one from NPM, your package version is behind
if [ $highest_semver == $latest_release ]; then
  echo "Package version already exists"
  exit 1;
fi