Automatically add the current repo and subpackages' `node_modules/.bin` to your `$PATH`

nodebin.zsh

# source this file in your ~/.zshrc

autoload -Uz add-zsh-hook

typeset -ga _git_nm_bins_current=()

_git_nm_path_remove_exact() {
    local needle="$1"
    local -a filtered=()
    local p

    for p in "${path[@]}"; do
        [[ "$p" == "$needle" ]] || filtered+=("$p")
    done

    path=("${filtered[@]}")
}

_git_nm_bin_hook() {
    emulate -L zsh
    setopt localoptions no_shwordsplit

    local repo_root dir bin
    local -a desired_bins=()

    # Remove bins previously injected by this hook.
    for bin in "${_git_nm_bins_current[@]}"; do
        _git_nm_path_remove_exact "$bin"
    done
    _git_nm_bins_current=()

    repo_root="$(git rev-parse --show-toplevel 2>/dev/null || true)"
    [[ -n "$repo_root" ]] || return 0

    # Canonicalize paths so comparisons work reliably.
    repo_root="${repo_root:A}"
    dir="${PWD:A}"

    # Collect every node_modules/.bin from the current dir up to the git root.
    while :; do
        bin="$dir/node_modules/.bin"
        [[ -d "$bin" ]] && desired_bins+=("$bin")

        [[ "$dir" == "$repo_root" ]] && break
        [[ "$dir" == "/" ]] && break
        dir="${dir:h}"
    done

    # Remove any existing occurrences so order is correct, then prepend.
    for bin in "${desired_bins[@]}"; do
        _git_nm_path_remove_exact "$bin"
    done

    if (( ${#desired_bins} )); then
        path=("${desired_bins[@]}" "${path[@]}")
        _git_nm_bins_current=("${desired_bins[@]}")
    fi
}

add-zsh-hook chpwd _git_nm_bin_hook
_git_nm_bin_hook