🔧 Add release versioning script

Usage: $ ./release.sh “1.0.0”

release.sh

@@ -0,0 +1,113 @@
+#!/bin/sh
+
+# MIT License
+# 
+# Copyright (c) 2021 Segment
+# 
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+# 
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+# Original source: https://github.com/segmentio/analytics-swift/blob/main/release.sh
+
+# check if `gh` tool is installed.
+if ! command -v gh &> /dev/null
+then
+	echo "Github CLI tool is required, but could not be found."
+	echo "Install it via: $ brew install gh"
+	exit 1
+fi
+
+# check if `gh` tool has auth access.
+# command will return non-zero if not auth'd.
+authd=$(gh auth status -t)
+if [[ $? != 0 ]]
+then
+	echo "ex: $ gh auth login"
+	exit 1
+fi
+
+# check that we're on the `main` branch
+branch=$(git rev-parse --abbrev-ref HEAD)
+if [ $branch != 'main' ]
+then
+	echo "The 'main' must be the current branch to make a release."
+	echo "You are currently on: $branch"
+	exit 1
+fi
+
+if [ -n "$(git status --porcelain)" ]
+then
+  echo "There are uncommited changes. Please commit and create a pull request or stash them.";
+  exit 1
+fi
+
+# find the latest semantic version from the git tags
+version=$(git tag | head -1)
+while read tagVersion
+do
+	if [ $(./scripts/semver.sh $tagVersion $version) == '1' ]
+	then
+		version=$tagVersion
+	fi
+done <<< "$(git tag)"
+
+echo "Analytics-Swift Appcues current version: $version"
+
+# no args, so give usage.
+if [ $# -eq 0 ]
+then
+	echo "Release automation script"
+	echo ""
+	echo "Usage: $ ./release.sh <version>"
+	echo "   ex: $ ./release.sh \"1.0.2\""
+	exit 0
+fi
+
+newVersion="${1}"
+echo "Preparing to release $newVersion..."
+
+versionComparison=$(./scripts/semver.sh $newVersion $version)
+
+if [ $versionComparison != '1' ]
+then
+	echo "New version must be greater than previous version ($version)."
+	exit 1
+fi
+
+read -r -p "Are you sure you want to release $newVersion? [y/N] " response
+case "$response" in
+	[yY][eE][sS]|[yY])
+		;;
+	*)
+		exit 1
+		;;
+esac
+
+# get the commits since the last release, filtering ones that aren't relevant.
+changelog=$(git log --pretty=format:"- [%as] %s (%h)" $(git describe --tags --abbrev=0 @^)..@ --abbrev=7 | sed '/[🔧🎬⬆️📸✅💡📝]/d')
+tempFile=$(mktemp)
+# write changelog to temp file.
+echo "$changelog" >> $tempFile
+
+cat $tempFile
+
+# gh release will make both the tag and the release itself.
+gh release create $newVersion -F $tempFile -t $newVersion
+
+# remove the tempfile.
+rm $tempFile