feat: script to generate builder changelog

scripts/generate-changelog.sh

@@ -0,0 +1,104 @@
+#!/bin/bash
+set -euo pipefail
+
+# Usage: ./scripts/generate-changelog.sh [from-tag] [to-ref]
+# Example: ./scripts/generate-changelog.sh v0.15.0 HEAD
+# Example: ./scripts/generate-changelog.sh v0.15.0 v0.16.0
+
+FROM_TAG="${1:-$(git describe --tags --abbrev=0)}"
+TO_REF="${2:-HEAD}"
+
+echo "# Buildpack Changelog"
+echo "**From:** $FROM_TAG ($(git log -1 --format=%ai "$FROM_TAG" | cut -d' ' -f1))"
+echo "**To:** $TO_REF ($(date +%Y-%m-%d))"
+echo ""
+echo "---"
+echo ""
+
+for buildpack in dotnet-core go java java-native-image nodejs php python ruby runway; do
+  diff=$(git diff "$FROM_TAG..$TO_REF" "meta/$buildpack/buildpack.toml" 2>/dev/null || true)
+
+  if [ -z "$diff" ]; then
+    continue
+  fi
+
+  old_version=$(git show "$FROM_TAG:meta/$buildpack/buildpack.toml" 2>/dev/null | grep "^  version = " | head -1 | cut -d'"' -f2 || echo "unknown")
+  new_version=$(git show "$TO_REF:meta/$buildpack/buildpack.toml" 2>/dev/null | grep "^  version = " | head -1 | cut -d'"' -f2 || echo "unknown")
+
+  echo "## $buildpack"
+  echo "**Buildpack:** $old_version → **$new_version**"
+  echo ""
+  echo "### Dependency Updates"
+
+  # Parse dependency updates
+  git diff "$FROM_TAG..$TO_REF" "meta/$buildpack/buildpack.toml" 2>/dev/null | \
+    grep -E "^\+.*version = |^\-.*version = " | \
+    while IFS= read -r line; do
+      if [[ $line =~ version\ =\ \"([^\"]+)\" ]]; then
+        version="${BASH_REMATCH[1]}"
+        if [[ $line == -* ]]; then
+          echo "OLD::$version"
+        else
+          echo "NEW::$version"
+        fi
+      fi
+    done | \
+    paste -d' ' - - | \
+    while read -r old_line new_line; do
+      old_ver="${old_line#OLD::}"
+      new_ver="${new_line#NEW::}"
+
+      # Get dependency ID from the context
+      dep_id=$(git diff "$FROM_TAG..$TO_REF" "meta/$buildpack/buildpack.toml" 2>/dev/null | \
+        grep -B2 "version = \"$old_ver\"" | \
+        grep "id = " | \
+        head -1 | \
+        cut -d'"' -f2 || echo "unknown")
+
+      if [ "$dep_id" != "unknown" ] && [ "$old_ver" != "$new_ver" ]; then
+        # Check for major version changes
+        old_major=$(echo "$old_ver" | cut -d. -f1)
+        new_major=$(echo "$new_ver" | cut -d. -f1)
+
+        if [ "$old_major" != "$new_major" ]; then
+          echo "- **$dep_id** → $old_ver to $new_ver ⚠️ MAJOR"
+        else
+          echo "- $dep_id → $old_ver to $new_ver"
+        fi
+      fi
+    done | sort -u
+
+  echo ""
+  echo "---"
+  echo ""
+done
+
+echo "## Summary"
+echo ""
+total_updated=$(git diff "$FROM_TAG..$TO_REF" -- 'meta/*/buildpack.toml' 2>/dev/null | grep -c "^diff --git" || echo 0)
+echo "**Total Buildpack Updates:** $total_updated"
+echo ""
+
+# Count major updates by looking for ⚠️ MAJOR markers in the output
+major_count=$(git diff "$FROM_TAG..$TO_REF" -- 'meta/*/buildpack.toml' 2>/dev/null | \
+  grep -E "^\+.*version = |^\-.*version = " | \
+  grep -v "^  version = " | \
+  while IFS= read -r line; do
+    if [[ $line =~ version\ =\ \"([^\"]+)\" ]]; then
+      version="${BASH_REMATCH[1]}"
+      major="${version%%.*}"
+      if [[ $line == -* ]]; then
+        echo "OLD::$major"
+      else
+        echo "NEW::$major"
+      fi
+    fi
+  done | \
+  paste -d' ' - - 2>/dev/null | \
+  awk '{if ($1 != $2) count++} END {print count+0}')
+
+if [ "${major_count:-0}" -gt 0 ]; then
+  echo "**Major Version Updates:** $major_count dependencies with major version bumps"
+else
+  echo "**Major Version Updates:** None"
+fi