Increment README version script

main.sh

#!/usr/bin/env bash
# Exit on first error, unset variable, or pipe failure
set -euo pipefail

# Define our constants
README_FILEPATH="README.md"

# Resolve our version being deployed
#   **1.0.0** -> 1.0.0
version="$(grep -E "\*\*\d+\.\d+\.\d+\*\*" "${README_FILEPATH}" | sed "s/\*//g")"

# Break up our versions
# https://stackoverflow.com/a/6253883
# DEV: `cut` can return the original string if the delimiter wasn't found, so we compare patch to the version
major="$(echo "$version" | cut -d . -f 1)"
minor="$(echo "$version" | cut -d . -f 2)"
patch="$(echo "$version" | cut -d . -f 3)"
if test "$version" == "" || test "$major" == "" || test "$minor" == "" || test "$patch" == "" || test "$patch" == "$version"; then
  echo "Unable to parse version \"${version}\"" 1>&2
  exit 1
fi

# Determine our increment target
increment_target="${1:-}"
if test "$increment_target" == ""; then
  increment_target="minor"
fi

# Increment our target version as requested
if test "$increment_target" == "major"; then
  # 1.6.3 -> 2.0.0
  major="$(($major + 1))"
  minor="0"
  patch="0"
elif test "$increment_target" == "minor"; then
  # 1.6.3 -> 1.7.0
  minor="$(($minor + 1))"
  patch="0"
elif test "$increment_target" == "patch"; then
  # 1.6.3 -> 1.6.4
  patch="$(($patch + 1))"
else
  echo "Unrecognized increment target \"${increment_target}\". Please specify \"major\", \"minor\", or \"patch\"" 1>&2
  echo "Usage: $0 [increment_target]" 1>&2
  exit 1
fi

# Set our new version in place
new_version="${major}.${minor}.${patch}"
sed -i "" -E "s/\*\*[0-9]+\.[0-9]+\.[0-9]+\*\*/**${new_version}**/" "${README_FILEPATH}"

# Output our new version
echo "$new_version"