pre-push

#!/usr/bin/env bash
# Pre-push hook: run formatters over committed branch changes.
# If formatters modify files, a fixup commit is created and the push is
# aborted so the caller can re-push with the clean state included.
#
# One-time setup:  git config core.hooksPath .githooks
# Emergency bypass: git push --no-verify  (discouraged)
set -euo pipefail

# Avoid infinite recursion when the hook itself creates the fixup commit.
[[ "${SKIP_FORMAT_HOOK:-}" == "1" ]] && exit 0

REPO_ROOT="$(git rev-parse --show-toplevel)"
cd "$REPO_ROOT"

# Abort early if there is uncommitted work in the tree; the formatter
# would mix those changes with committed ones and produce a misleading diff.
if ! git diff --quiet || ! git diff --cached --quiet; then
    echo "pre-push: working tree is dirty — stash or commit your changes first." >&2
    exit 1
fi

echo "pre-push: running formatters (./scripts/format.sh --pre-push)..." >&2
if ./scripts/format.sh --pre-push; then
    # Formatters exited cleanly — no files were changed.
    exit 0
fi

# format.sh exits 1 when it modifies files.  Collect what changed.
changed_files="$(git diff --name-only)"
if [[ -z "$changed_files" ]]; then
    # Formatter failed for a reason other than file modifications (e.g. lint error).
    echo "pre-push: formatters failed without modifying files — fix the errors above." >&2
    exit 1
fi

# Stage only the files the formatters touched and create a fixup commit.
echo "$changed_files" | xargs git add --
SKIP_FORMAT_HOOK=1 git commit -m "chore: apply formatters before push"

echo "" >&2
echo "pre-push: formatters modified the following files and a commit was created:" >&2
echo "$changed_files" | sed 's/^/  /' >&2
echo "" >&2

# Verify the tree is now clean to catch non-idempotent formatters.
if ! ./scripts/format.sh --pre-push; then
    echo "pre-push: formatters are not idempotent — fix the remaining issues above." >&2
    exit 1
fi

echo "pre-push: re-run 'git push' to include the formatter commit." >&2
exit 1