Automagically create a go env for each git project

goproj_auto.sh

unset OLD_GOPATH

# Try to find the nearest GOPATH under the given dir
func goproj_home() {
  local dir="${1:-"$PWD"}/"

  until [[ -z "$dir" ]]; do
    dir="${dir%/*}"

    if [[ -d "$dir/src" ]] && [[ -d "$dir/bin" ]] && [[ -d "$dir/pkg" ]]; then
      echo "$dir"
      break
    fi
  done
}

# Find the nearest git repo under the given dir
func goproj_repo() {
  local dir="${1:-"$PWD"}/"

  until [[ -z "$dir" ]]; do
    dir="${dir%/*}"

    if [[ -d "$dir/.git" ]]; then
      echo "$dir"
      break
    fi
  done
}

# Automagically create a go env for each git repo
function goproj_auto() {
  local gohome="$(goproj_home)"
  local gorepo="$(goproj_repo)"
  local goproj="${gorepo#"$gohome/src/"}"
  local gopath="$HOME/.goproj/$goproj"

  # Exited repo, restore original go env values
  if [[ -z "$gohome" ]] || [[ -z "$gorepo" ]]; then
    [[ -z "$OLD_GOPATH" ]] && return
    export GOPATH="$OLD_GOPATH"
    export GOBIN="$GOPATH/bin"
    export PATH="$OLD_PATH"
    unset OLD_GOPATH
    unset OLD_PATH
    return
  fi

  # Same repo, no need to modify go env
  [[ "$gopath:$gohome" == "$GOPATH" ]] && return

  # Entering repo, save go env and set new values
  mkdir -p "$gopath"/{bin,pkg,src}
  export OLD_PATH="$PATH"
  export OLD_GOPATH="$GOPATH"
  export GOPATH="$gopath:$gohome"
  export GOBIN="$gopath/bin:$gohome/bin"
  export PATH="$GOBIN:$PATH"
}

# Execute before each ZSH command
if [[ -n "$ZSH_VERSION" ]]; then
  if [[ ! "$preexec_functions" == *goproj_auto* ]]; then
    preexec_functions+=("goproj_auto")
  fi
fi