magpie/internal/proc/path_other.go

//go:build !windows

package proc

import (
	"context"
	"os"
	"path/filepath"
	"slices"
	"strings"
	"time"
)

// UserPath gives the desktop app the PATH a terminal of the user's has. One
// opened from the Finder, the Dock or a login item gets launchd's
// /usr/bin:/bin:/usr/sbin:/sbin and nothing a shell profile adds, so a claude
// or codex installed with a custom npm prefix (~/.npm-global/bin), nvm, bun,
// volta or asdf wasn't found: the agent wasn't seen and its subscription
// couldn't be used. The folders those tools use are added at once, when they
// exist; the login shell's own PATH is asked for in the background and
// added after, since a slow profile mustn't hold the window up.
func UserPath() {
	addPath(userDirs(false))
	go func() {
		if p := shellPath(); p != "" {
			addPath(filepath.SplitList(p))
		}
	}()
}

// UserBinDirs are the folders a user's command-line tools are installed in
// that exist here — npm's prefixes, each Node version of nvm, fnm and mise,
// bun, volta, pnpm, asdf, the standalone installers' ~/.local/bin,
// Homebrew — for finding one PATH doesn't reach.
func UserBinDirs() []string { return userDirs(true) }

func userDirs(everyNode bool) []string {
	home, _ := os.UserHomeDir()
	var known []string
	for _, d := range []string{".local/bin", ".npm-global/bin", ".npm/bin", ".bun/bin", ".volta/bin", ".asdf/shims", ".local/share/mise/shims", ".cargo/bin", ".deno/bin", "Library/pnpm"} {
		known = append(known, filepath.Join(home, d))
	}
	nodes := func(pattern string) {
		vs, _ := filepath.Glob(filepath.Join(home, pattern))
		if len(vs) == 0 {
			return
		}
		if !everyNode {
			known = append(known, vs[len(vs)-1])
			return
		}
		slices.Reverse(vs)
		known = append(known, vs...)
	}
	nodes(".nvm/versions/node/*/bin")
	if everyNode {
		known = append(known, filepath.Join(home, ".local/share/pnpm"), npmPrefix(home))
		nodes(".local/share/mise/installs/node/*/bin")
		nodes(".local/share/fnm/node-versions/*/installation/bin")
		nodes("Library/Application Support/fnm/node-versions/*/installation/bin")
	}
	known = append(known, "/opt/homebrew/bin", "/usr/local/bin")
	var have []string
	for _, d := range known {
		if st, err := os.Stat(d); d != "" && err == nil && st.IsDir() {
			have = append(have, d)
		}
	}
	return have
}

// npmPrefix is the bin folder of the npm prefix ~/.npmrc names, "" when it
// names none.
func npmPrefix(home string) string {
	b, err := os.ReadFile(filepath.Join(home, ".npmrc"))
	if err != nil {
		return ""
	}
	for _, line := range strings.Split(string(b), "\n") {
		k, v, ok := strings.Cut(line, "=")
		if !ok || strings.TrimSpace(k) != "prefix" {
			continue
		}
		v = strings.Trim(strings.TrimSpace(v), `"'`)
		if strings.HasPrefix(v, "~/") {
			v = filepath.Join(home, v[2:])
		}
		if filepath.IsAbs(v) {
			return filepath.Join(v, "bin")
		}
	}
	return ""
}

// shellPath asks the user's login shell for its PATH; "" when it can't say
// within a few seconds.
func shellPath() string {
	sh := os.Getenv("SHELL")
	if sh == "" || !filepath.IsAbs(sh) {
		sh = "/bin/zsh"
		if _, err := os.Stat(sh); err != nil {
			sh = "/bin/sh"
		}
	}
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	// interactive too, since many put PATH in .zshrc/.bashrc; the marker
	// tells PATH apart from whatever the profile prints
	const mark = "__magpie_path__"
	cmd := CommandContext(ctx, sh, "-ilc", "printf '"+mark+"%s"+mark+"' \"$PATH\"")
	cmd.Stdin = nil
	out, _ := cmd.Output()
	s := string(out)
	i := strings.Index(s, mark)
	if i < 0 {
		return ""
	}
	s = s[i+len(mark):]
	j := strings.Index(s, mark)
	if j < 0 {
		return ""
	}
	return s[:j]
}

// addPath adds the folders PATH lacks, after the ones it has.
func addPath(dirs []string) {
	cur := filepath.SplitList(os.Getenv("PATH"))
	seen := map[string]bool{}
	for _, d := range cur {
		seen[d] = true
	}
	for _, d := range dirs {
		if d != "" && filepath.IsAbs(d) && !seen[d] {
			seen[d] = true
			cur = append(cur, d)
		}
	}
	os.Setenv("PATH", strings.Join(cur, string(os.PathListSeparator)))
}