Adding script to prepare release

scripts/prepare-release.sh

@@ -0,0 +1,104 @@
+#!/usr/bin/env bash
+#
+# prepare-release.sh
+# (Note: This should be called by `make release/prepare` because it depends
+#   on several variables set by the Makefile)
+#
+# Performs release preparation tasks:
+#   - Creates a release branch
+#   - Renames "LATEST" section to the new version number
+#   - Adds new "LATEST" entry to the changelog
+#
+##############################################
+set -Eeuo pipefail
+
+if [[ -z "${NEW_VERSION:-}" ]]; then
+    echo "[ERROR] NEW_VERSION environment variable not defined." >&2
+    exit 1
+fi
+
+# Script called from within a git repo?
+if [[ $(git rev-parse --is-inside-work-tree &>/dev/null) -ne 0 ]]; then
+    echo "[ERROR] Current directory (${SRCDIR}) is not a git repository" >&2
+    exit 1
+fi
+
+REPO_ROOT=$(git rev-parse --show-toplevel)
+CHANGELOG_FILENAME=${CHANGELOG:-"CHANGELOG.md"}
+
+# normalize version by removing `v` prefix
+VERSION_NUM=${NEW_VERSION/#v/}
+RELEASE_BRANCH=$(printf "release/v%s" "${VERSION_NUM}")
+
+function updateChangelog() {
+    local tmpfile
+
+    trap '[ -e "${tmpfile}" ] && rm "${tmpfile}"' RETURN
+
+    local changelogFile
+    changelogFile=$(printf "%s/%s" "${REPO_ROOT}" "${CHANGELOG_FILENAME}")
+
+    # create Changelog file if not exists
+    if ! [[ -f "${REPO_ROOT}/${CHANGELOG_FILENAME}" ]]; then
+        touch "${REPO_ROOT}/${CHANGELOG_FILENAME}" && \
+        git add "${REPO_ROOT}/${CHANGELOG_FILENAME}"
+    fi
+
+    tmpfile=$(mktemp)
+
+    # Replace "Latest" in the top-most changelog block with new version
+    # Then push a new "latest" block to top of the changelog
+    awk 'NR==1, /---/{ sub(/START\/LATEST/, "START/v'${VERSION_NUM}'"); sub(/# Latest/, "# v'${VERSION_NUM}'") } {print}' \
+     "${changelogFile}" > "${tmpfile}"
+
+    # Inserts "Latest" changelog HEREDOC at the top of the file
+    cat - "${tmpfile}" << EOF > "${REPO_ROOT}/${CHANGELOG_FILENAME}"
+[//]: # (START/LATEST)
+# Latest
+
+## Features
+  * A user-friendly description of a new feature. {issue-number}
+
+## Fixes
+ * A user-friendly description of a fix. {issue-number}
+
+## Security
+ * A user-friendly description of a security fix. {issue-number}
+
+---
+
+EOF
+}
+
+function _main() {
+
+    # Stash version changes
+    git stash push &>/dev/null
+
+    if ! git checkout -b "${RELEASE_BRANCH}" origin/"${MAIN_BRANCH:-main}"; then
+        echo "[ERROR] Could not check out release branch." >&2
+        git stash pop &>/dev/null
+        exit 1
+    fi
+
+    # Add the version changes to release branch
+    git stash pop &>/dev/null
+
+    updateChangelog
+
+    cat << EOF
+
+[SUCCESS] Changelog updated & release branch created:
+    New Version:    ${NEW_VERSION}
+    Release Branch: ${RELEASE_BRANCH}
+
+Next steps:
+    1. Edit the changelog notes in ${CHANGELOG_FILENAME}
+    2. Commit changes to the release branch
+    3. Push changes to remote => git push origin ${RELEASE_BRANCH}
+
+EOF
+    exit 0
+}
+
+_main