chore: check for updates (#48)

Author: notnmeyer

cmd/root.go

@@ -1,11 +1,9 @@
-/*
-Copyright © 2026 NAME HERE <EMAIL ADDRESS>
-*/
 package cmd
 
 import (
 	"fmt"
 	"os"
+	"time"
 
 	"github.com/loops-so/cli/internal/api"
 	"github.com/loops-so/cli/internal/config"
@@ -52,11 +50,24 @@ func fixHelpFlags(cmd *cobra.Command) {
 	}
 }
 
-// Execute adds all child commands to the root command and sets flags appropriately.
-// This is called by main.main(). It only needs to happen once to the rootCmd.
 func Execute() {
+	defer func() {
+		if updateCheckDone != nil {
+			select {
+			case <-updateCheckDone:
+			case <-time.After(500 * time.Millisecond):
+			}
+		}
+		if updateCheckCancel != nil {
+			updateCheckCancel()
+		}
+	}()
+
 	fixHelpFlags(rootCmd)
 	err := rootCmd.Execute()
+
+	checkForUpdate(os.Stderr)
+
 	if err != nil {
 		if isJSONOutput() {
 			printJSON(os.Stderr, Result{Success: false, Message: err.Error()})
@@ -68,14 +79,6 @@ func Execute() {
 }
 
 func init() {
-	// Here you will define your flags and configuration settings.
-	// Cobra supports persistent flags, which, if defined here,
-	// will be global for your application.
-
-	// rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.cli.yaml)")
-
-	// Cobra also supports local flags, which will only run
-	// when this action is called directly.
 	rootCmd.PersistentFlags().VarP(&outputFormat, "output", "o", "Output format (text, json)")
 	rootCmd.PersistentFlags().StringVarP(&teamFlag, "team", "t", "", "Team key name to use")
 	rootCmd.PersistentFlags().BoolVar(&debugFlag, "debug", false, "Print API request details before sending")

cmd/update_check.go

@@ -0,0 +1,183 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"time"
+
+	"github.com/loops-so/cli/internal/config"
+)
+
+var (
+	updateCheckDone   chan struct{}
+	updateCheckCancel context.CancelFunc
+)
+
+const updateCheckInterval = 24 * time.Hour
+
+type updateCache struct {
+	LatestVersion string    `json:"latest_version"`
+	CheckedAt     time.Time `json:"checked_at"`
+}
+
+func checkForUpdate(w io.Writer) {
+	if version == "dev" || isJSONOutput() {
+		return
+	}
+
+	dir, err := config.ConfigDir()
+	if err != nil {
+		return
+	}
+	path := filepath.Join(dir, "update-check.json")
+
+	cache, err := readUpdateCache(path)
+	if err != nil {
+		if debugFlag {
+			fmt.Fprintf(w, "[debug] update check: no cache (%v)\n", err)
+		}
+	} else {
+		if debugFlag {
+			age := time.Since(cache.CheckedAt).Truncate(time.Second)
+			fmt.Fprintf(w, "[debug] update check: cached latest=%s age=%s\n", cache.LatestVersion, age)
+		}
+		if isNewerVersion(cache.LatestVersion, version) {
+			fmt.Fprintf(w, "\nA new version of loops is available: v%s → v%s\nRun this to update:\n\n  %s\n\n", version, cache.LatestVersion, upgradeCommand())
+		}
+	}
+
+	if err != nil || time.Since(cache.CheckedAt) > updateCheckInterval {
+		if debugFlag {
+			fmt.Fprintf(w, "[debug] update check: fetching latest release in background\n")
+		}
+		ctx, cancel := context.WithCancel(context.Background())
+		updateCheckCancel = cancel
+		updateCheckDone = make(chan struct{})
+		go func() {
+			defer close(updateCheckDone)
+			fetchAndCacheLatestVersion(ctx, path)
+		}()
+	}
+}
+
+func readUpdateCache(path string) (*updateCache, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	var c updateCache
+	if err := json.Unmarshal(data, &c); err != nil {
+		return nil, err
+	}
+	return &c, nil
+}
+
+func fetchAndCacheLatestVersion(ctx context.Context, path string) {
+	client := &http.Client{Timeout: 5 * time.Second}
+	req, err := http.NewRequestWithContext(ctx, "GET", "https://api.github.com/repos/loops-so/cli/releases/latest", nil)
+	if err != nil {
+		return
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return
+	}
+
+	var release struct {
+		TagName string `json:"tag_name"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&release); err != nil {
+		return
+	}
+
+	latest := strings.TrimPrefix(release.TagName, "v")
+	if latest == "" {
+		return
+	}
+
+	cache := updateCache{
+		LatestVersion: latest,
+		CheckedAt:     time.Now(),
+	}
+	data, err := json.Marshal(cache)
+	if err != nil {
+		return
+	}
+
+	_ = os.MkdirAll(filepath.Dir(path), 0o700)
+	_ = os.WriteFile(path, data, 0o600)
+}
+
+func upgradeCommand() string {
+	if isHomebrew() {
+		return "brew upgrade loops"
+	}
+	installDir := binDir()
+	if runtime.GOOS == "windows" {
+		if installDir != "" {
+			return fmt.Sprintf(`irm https://raw.githubusercontent.com/loops-so/cli/main/install.ps1 | iex -Args "-InstallDir '%s'"`, installDir)
+		}
+		return `irm https://raw.githubusercontent.com/loops-so/cli/main/install.ps1 | iex`
+	}
+	if installDir != "" {
+		return fmt.Sprintf(`curl -fsSL --proto '=https' --tlsv1.2 https://cli.loops.so | bash -s -- latest %s`, installDir)
+	}
+	return `curl -fsSL --proto '=https' --tlsv1.2 https://cli.loops.so | bash`
+}
+
+func binDir() string {
+	exe, err := os.Executable()
+	if err != nil {
+		return ""
+	}
+	return filepath.Dir(exe)
+}
+
+func isHomebrew() bool {
+	exe, err := os.Executable()
+	if err != nil {
+		return false
+	}
+	resolved, err := filepath.EvalSymlinks(exe)
+	if err != nil {
+		return false
+	}
+	lower := strings.ToLower(resolved)
+	return strings.Contains(lower, "cellar") || strings.Contains(lower, "homebrew") || strings.Contains(lower, "linuxbrew")
+}
+
+// isNewerVersion reports whether latest is newer than current (semver without v prefix).
+func isNewerVersion(latest, current string) bool {
+	l := parseSemver(latest)
+	c := parseSemver(current)
+	for i := 0; i < 3; i++ {
+		if l[i] > c[i] {
+			return true
+		}
+		if l[i] < c[i] {
+			return false
+		}
+	}
+	return false
+}
+
+func parseSemver(v string) [3]int {
+	v = strings.TrimPrefix(v, "v")
+	var parts [3]int
+	fmt.Sscanf(v, "%d.%d.%d", &parts[0], &parts[1], &parts[2])
+	return parts
+}