Git worktree hook

post-checkout

#!/usr/bin/env bash

set -euo pipefail

# Initialize linked worktrees once.
if [[ -f .git && ! -d .git ]]; then
  gitdir="$(git rev-parse --git-dir)"
  marker="$gitdir/worktree-initialized"
  if [[ ! -f "$marker" ]]; then
    COMMON_DIR="$(dirname "$(git rev-parse --git-common-dir)")"

    items=(.env .envrc .venv)

    for item in "${items[@]}"; do
      src="$COMMON_DIR/$item"
      dest="$item"

      if [[ ! -e "$src" ]]; then
        echo "warning: $src does not exist; skipping link" >&2
        continue
      fi

      if [[ -L "$dest" ]]; then
        target="$(readlink "$dest")"
        if [[ "$target" != /* ]]; then
          target="$(cd "$(dirname "$dest")" && pwd)/$target"
        fi
        if command -v realpath >/dev/null 2>&1; then
          target="$(realpath "$target")"
          src="$(realpath "$src")"
        fi
        if [[ "$target" != "$src" ]]; then
          echo "warning: $dest already links to $target (expected $src)" >&2
        fi
        continue
      fi

      if [[ -e "$dest" ]]; then
        echo "warning: $dest already exists; skipping link" >&2
        continue
      fi

      ln -s "$src" "$dest"
    done

    if [[ -f .gitmodules ]] && grep -q 'path = ' .gitmodules; then
      git submodule update --init --recursive --depth 1
    fi

    if command -v direnv >/dev/null 2>&1; then
      direnv allow
    fi

    printf '%s\n' "$(date -u +"%Y-%m-%dT%H:%M:%SZ")" > "$marker"
  fi
fi