[feat] Add --auto flag to release script (#15)

feat(release): add automatic version detection flag

Author: lugassawan

scripts/release.sh

@@ -2,13 +2,14 @@
 set -eu
 
 usage() {
-    echo "Usage: $0 <version>"
+    echo "Usage: $0 <version|--auto>"
     echo ""
     echo "Create and push a release tag to trigger the GitHub Actions release workflow."
     echo ""
     echo "Examples:"
-    echo "  $0 0.1.0"
-    echo "  $0 v0.1.0"
+    echo "  $0 1.1.0"
+    echo "  $0 v1.1.0"
+    echo "  $0 --auto"
     exit 1
 }
 
@@ -17,16 +18,169 @@ die() {
     exit 1
 }
 
-# Require a version argument
+# Detect next version by analyzing commits since the last tag.
+# Classifies commits by prefix and determines the appropriate semver bump.
+detect_next_version() {
+    # Find latest semver tag
+    latest_tag=$(git tag -l 'v*' | sort -V | tail -1)
+    if [ -z "$latest_tag" ]; then
+        latest_tag="v0.0.0"
+        echo "No existing tags found. Starting from v0.0.0."
+        commit_range="HEAD"
+    else
+        commit_range="${latest_tag}..HEAD"
+    fi
+
+    # Get commits since last tag
+    commits=$(git log "$commit_range" --oneline 2>/dev/null || true)
+    if [ -z "$commits" ]; then
+        echo "No commits since $latest_tag. Nothing to release."
+        exit 0
+    fi
+
+    commit_count=$(echo "$commits" | wc -l | tr -d ' ')
+
+    # Classify commits by prefix and determine bump type
+    bump="patch"
+    breaking_commits=""
+    feat_commits=""
+    other_commits=""
+
+    # Use a temp file to handle BREAKING CHANGE body detection without subshell issues
+    body_breaking_file=$(mktemp)
+    trap 'rm -f "$body_breaking_file"' EXIT
+
+    # Check commit bodies for BREAKING CHANGE
+    git log "$commit_range" --format="%H" 2>/dev/null | while IFS= read -r hash; do
+        body=$(git log -1 --format="%b" "$hash")
+        case "$body" in
+            *"BREAKING CHANGE"*)
+                subject=$(git log -1 --format="%s" "$hash")
+                echo "$subject" >> "$body_breaking_file"
+                ;;
+        esac
+    done
+
+    # Process each commit
+    OLD_IFS="$IFS"
+    IFS='
+'
+    for line in $commits; do
+        subject=$(echo "$line" | sed 's/^[a-f0-9]* //')
+        case "$subject" in
+            \[breaking\]*|\[BREAKING\]*)
+                bump="major"
+                breaking_commits="${breaking_commits}    - ${subject}
+"
+                ;;
+            \[feat\]*|\[Feat\]*)
+                if [ "$bump" != "major" ]; then
+                    bump="minor"
+                fi
+                feat_commits="${feat_commits}    - ${subject}
+"
+                ;;
+            *)
+                other_commits="${other_commits}    - ${subject}
+"
+                ;;
+        esac
+    done
+    IFS="$OLD_IFS"
+
+    # Incorporate BREAKING CHANGE from commit bodies
+    if [ -s "$body_breaking_file" ]; then
+        bump="major"
+        OLD_IFS="$IFS"
+        IFS='
+'
+        for body_subject in $(cat "$body_breaking_file"); do
+            # Avoid duplicating commits already listed as [breaking]
+            case "$breaking_commits" in
+                *"$body_subject"*) ;;
+                *) breaking_commits="${breaking_commits}    - ${body_subject} (BREAKING CHANGE in body)
+" ;;
+            esac
+        done
+        IFS="$OLD_IFS"
+    fi
+
+    # Parse current version
+    major=$(echo "$latest_tag" | sed 's/^v//' | cut -d. -f1)
+    minor=$(echo "$latest_tag" | sed 's/^v//' | cut -d. -f2)
+    patch=$(echo "$latest_tag" | sed 's/^v//' | cut -d. -f3)
+
+    # Compute next version
+    case "$bump" in
+        major)
+            major=$((major + 1))
+            minor=0
+            patch=0
+            ;;
+        minor)
+            minor=$((minor + 1))
+            patch=0
+            ;;
+        patch)
+            patch=$((patch + 1))
+            ;;
+    esac
+
+    next_version="v${major}.${minor}.${patch}"
+
+    # Print summary
+    echo ""
+    echo "Current version: $latest_tag"
+    echo "Commits since $latest_tag: $commit_count"
+    echo ""
+
+    if [ -n "$breaking_commits" ]; then
+        echo "  Breaking changes (major):"
+        printf "%s" "$breaking_commits"
+        echo ""
+    fi
+
+    if [ -n "$feat_commits" ]; then
+        echo "  Features (minor):"
+        printf "%s" "$feat_commits"
+        echo ""
+    fi
+
+    if [ -n "$other_commits" ]; then
+        echo "  Other:"
+        printf "%s" "$other_commits"
+        echo ""
+    fi
+
+    echo "Next version: $next_version"
+    echo ""
+
+    # Prompt for confirmation
+    printf "Continue with release? [y/N] "
+    read -r confirm
+    case "$confirm" in
+        [yY]|[yY][eE][sS]) ;;
+        *) echo "Aborted."; exit 0 ;;
+    esac
+
+    # Set version for the rest of the script
+    version="$next_version"
+}
+
+# Require exactly one argument
 [ $# -eq 1 ] || usage
 
-version="$1"
+if [ "$1" = "--auto" ]; then
+    detect_next_version
+else
+    version="$1"
 
-# Normalize: ensure v prefix
-case "$version" in
-    v*) ;;
-    *)  version="v${version}" ;;
-esac
+    # Normalize: ensure v prefix
+    case "$version" in
+        v*) ;;
+        *)  version="v${version}" ;;
+    esac
+fi
 
 # Validate semver format (vX.Y.Z)
 echo "$version" | grep -qE '^v[0-9]+\.[0-9]+\.[0-9]+$' \