chore: update merge-branches.sh

Author: jurajhilje

api/scripts/merge-branches.sh

@@ -18,13 +18,30 @@
 
 set -euo pipefail
 
+log() {
+  echo "==> $*"
+}
+
+error() {
+  echo "==> ERROR: $*" >&2
+}
+
+fail() {
+  error "$@"
+  exit 1
+}
+
+# Catch-all for any command that fails without its own error message.
+trap 'error "Command failed (exit $?) at line $LINENO: $BASH_COMMAND"' ERR
+
 remote="${1:-}"
 
 if [[ -z "$remote" ]]; then
   read -r -p "Remote (e.g. origin): " remote < /dev/tty
 fi
 
 if [[ -z "$remote" ]]; then
+  error "Remote is required."
   echo "Usage: $0 <remote> [branches]" >&2
   exit 1
 fi
@@ -42,8 +59,7 @@ else
 fi
 
 if ! git remote get-url "$remote" > /dev/null 2>&1; then
-  echo "Error: remote '$remote' does not exist." >&2
-  exit 1
+  fail "Remote '$remote' does not exist."
 fi
 
 branches=()
@@ -55,66 +71,97 @@ while IFS= read -r line; do
 done <<< "$input"
 
 if [[ ${#branches[@]} -lt 2 ]]; then
-  echo "Error: at least 2 branches are required." >&2
-  exit 1
+  fail "At least 2 branches are required, got ${#branches[@]}."
 fi
 
 for branch in "${branches[@]}"; do
   if ! git rev-parse --verify --quiet "refs/heads/$branch" > /dev/null; then
-    echo "Error: local branch '$branch' does not exist." >&2
-    exit 1
+    fail "Local branch '$branch' does not exist."
   fi
 done
 
 if [[ -n "$(git status --porcelain --untracked-files=no)" ]]; then
-  echo "Error: working tree has uncommitted changes. Commit or stash them first." >&2
-  exit 1
+  fail "Working tree has uncommitted changes. Commit or stash them first."
 fi
 
 start_branch="$(git rev-parse --abbrev-ref HEAD)"
+branch_count=${#branches[@]}
+merge_count=$((branch_count - 1))
 
 in_merge() {
   git rev-parse --verify --quiet MERGE_HEAD > /dev/null
 }
 
-for ((i = 1; i < ${#branches[@]}; i++)); do
+log "Remote: $remote"
+log "Merge order: $(printf '%s -> ' "${branches[@]}" | sed 's/ -> $//')"
+
+for ((i = 1; i < branch_count; i++)); do
   source_branch="${branches[i - 1]}"
   target_branch="${branches[i]}"
 
   echo
-  echo "==> Merging '$source_branch' into '$target_branch'"
-  git checkout --quiet "$target_branch"
+  log "[$i/$merge_count] Checking out '$target_branch'"
+  if ! git checkout --quiet "$target_branch"; then
+    fail "Could not check out '$target_branch'."
+  fi
 
+  if git merge-base --is-ancestor "$source_branch" HEAD; then
+    log "[$i/$merge_count] '$target_branch' already contains '$source_branch', nothing to merge"
+    continue
+  fi
+
+  log "[$i/$merge_count] Merging '$source_branch' into '$target_branch'"
   if git merge --no-edit "$source_branch"; then
+    log "[$i/$merge_count] Merged '$source_branch' into '$target_branch'"
     continue
   fi
 
   if ! in_merge; then
-    echo "Error: merge of '$source_branch' into '$target_branch' failed." >&2
-    exit 1
+    fail "Merge of '$source_branch' into '$target_branch' failed (see git output above). You are on '$target_branch'."
   fi
 
+  error "Merge conflicts while merging '$source_branch' into '$target_branch':"
+  git diff --name-only --diff-filter=U | sed 's/^/      /' >&2
   while true; do
     echo
-    echo "Merge conflicts in '$target_branch'. Resolve them and commit the merge."
+    echo "Resolve the conflicts in '$target_branch' and commit the merge."
     read -r -p "Press Enter to continue..." < /dev/tty
 
     if in_merge; then
-      echo "Merge is still in progress (unresolved conflicts or not committed yet)."
+      error "Merge is still in progress (unresolved conflicts or not committed yet)."
     elif ! git merge-base --is-ancestor "$source_branch" HEAD; then
-      echo "'$source_branch' is not merged into '$target_branch' (was the merge aborted?)."
-      echo "Run 'git merge $source_branch', resolve and commit, or press Ctrl+C to exit."
+      error "'$source_branch' is not merged into '$target_branch' (was the merge aborted?)."
+      echo "Run 'git merge $source_branch', resolve and commit, or press Ctrl+C to exit." >&2
     else
+      log "[$i/$merge_count] Merged '$source_branch' into '$target_branch' (conflicts resolved)"
       break
     fi
   done
 done
 
-git checkout --quiet "$start_branch"
-
 echo
-echo "==> Pushing to '$remote': ${branches[*]}"
-git push "$remote" "${branches[@]}"
+log "Switching back to '$start_branch'"
+if ! git checkout --quiet "$start_branch"; then
+  error "Could not switch back to '$start_branch', continuing with push."
+fi
+
+failed_pushes=()
+for ((i = 0; i < branch_count; i++)); do
+  branch="${branches[i]}"
+
+  echo
+  log "[$((i + 1))/$branch_count] Pushing '$branch' to '$remote'"
+  if git push --quiet "$remote" "$branch"; then
+    log "[$((i + 1))/$branch_count] Pushed '$branch' to '$remote'"
+  else
+    error "Failed to push '$branch' to '$remote'."
+    failed_pushes+=("$branch")
+  fi
+done
 
 echo
-echo "==> Done. Merged and pushed: ${branches[*]}"
+if [[ ${#failed_pushes[@]} -gt 0 ]]; then
+  fail "Merged all branches, but failed to push: ${failed_pushes[*]}"
+fi
+
+log "Done. Merged and pushed: ${branches[*]}"