fix: infinite loop if go.mod not found, add warning on missing templ …

…dep (#441)

fixes #418

.version

@@ -1 +1 @@
-0.2.529
+0.2.532

cmd/templ/generatecmd/main.go

@@ -13,10 +13,8 @@ import (
 	"net/http"
 	"net/url"
 	"os"
-	"os/signal"
 	"path"
 	"path/filepath"
-	"regexp"
 	"runtime"
 	"strings"
 	"sync"
@@ -25,6 +23,7 @@ import (
 	_ "net/http/pprof"
 
 	"github.com/a-h/templ"
+	"github.com/a-h/templ/cmd/templ/generatecmd/modcheck"
 	"github.com/a-h/templ/cmd/templ/generatecmd/proxy"
 	"github.com/a-h/templ/cmd/templ/generatecmd/run"
 	"github.com/a-h/templ/cmd/templ/visualize"
@@ -33,8 +32,6 @@ import (
 	"github.com/cenkalti/backoff/v4"
 	"github.com/cli/browser"
 	"github.com/fatih/color"
-	"golang.org/x/mod/modfile"
-	"golang.org/x/mod/semver"
 )
 
 type Arguments struct {
@@ -55,57 +52,22 @@ type Arguments struct {
 
 var defaultWorkerCount = runtime.NumCPU()
 
-func Run(w io.Writer, args Arguments) (err error) {
-	ctx, cancel := context.WithCancel(context.Background())
-	watchCtx, watchCancel := context.WithCancel(context.Background())
-
-	signalChan := make(chan os.Signal, 1)
-	signal.Notify(signalChan, os.Interrupt)
-	defer func() {
-		signal.Stop(signalChan)
-		cancel()
-	}()
+func Run(ctx context.Context, w io.Writer, args Arguments) (err error) {
 	if args.PPROFPort > 0 {
 		go func() {
 			_ = http.ListenAndServe(fmt.Sprintf("localhost:%d", args.PPROFPort), nil)
 		}()
 	}
 
-	go func() {
-		watching := args.Watch
-		for {
-			select {
-			case <-signalChan: // First signal, cancel context.
-				if watching {
-					fmt.Println("Stopping watch operation...")
-					watchCancel()
-					continue
-				}
-
-				if ctx.Err() != nil {
-					fmt.Fprintln(w, "\nHARD EXIT")
-					os.Exit(2) // hard exit
-					continue
-				}
-
-				fmt.Fprintln(w, "\nCancelling...")
-				cancel()
-
-			case <-ctx.Done():
-				break
-			}
-		}
-	}()
-
-	err = runCmd(ctx, watchCtx, w, args)
+	err = runCmd(ctx, w, args)
 	if errors.Is(err, context.Canceled) {
 		return nil
 	}
 
 	return err
 }
 
-func runCmd(ctx, watchCtx context.Context, w io.Writer, args Arguments) error {
+func runCmd(ctx context.Context, w io.Writer, args Arguments) error {
 	var err error
 
 	if args.Watch && args.FileName != "" {
@@ -148,18 +110,18 @@ func runCmd(ctx, watchCtx context.Context, w io.Writer, args Arguments) error {
 	}
 	fmt.Fprintln(w, "Processing path:", args.Path)
 
-	if err := checkTemplVersion(args.Path); err != nil {
+	if err := modcheck.Check(args.Path); err != nil {
 		logWarning(w, "templ version check failed: %v\n", err)
 	}
 
 	if args.Watch {
-		err = generateWatched(watchCtx, w, args, opts, p)
+		err = generateWatched(ctx, w, args, opts, p)
 		if err != nil && !errors.Is(err, context.Canceled) {
 			return err
 		}
 	}
 
-	return generateProduction(ctx, w, args, opts, p)
+	return generateProduction(context.Background(), w, args, opts, p)
 }
 
 func generateWatched(ctx context.Context, w io.Writer, args Arguments, opts []generator.GenerateOpt, p *proxy.Handler) error {
@@ -519,65 +481,3 @@ func logWithDecoration(w io.Writer, decoration string, col color.Attribute, form
 	color.New(col).Fprintf(w, "(%s) ", decoration)
 	fmt.Fprintf(w, format, a...)
 }
-
-// Replace "go 1.21.3" with "go 1.21" until https://github.com/golang/go/issues/61888 is fixed, see templ issue https://github.com/a-h/templ/issues/355
-var goVersionRegexp = regexp.MustCompile(`\ngo (\d+\.\d+)(?:\D.+)\n`)
-
-func patchGoVersion(moduleFileContents []byte) []byte {
-	return goVersionRegexp.ReplaceAll(moduleFileContents, []byte("\ngo $1\n"))
-}
-
-func checkTemplVersion(dir string) error {
-	// Walk up the directory tree, starting at dir, until we find a go.mod file.
-	// If it contains a go.mod file, parse it and find the templ version.
-	dir, err := filepath.Abs(dir)
-	if err != nil {
-		return fmt.Errorf("failed to get absolute path: %w", err)
-	}
-	for {
-		current := filepath.Join(dir, "go.mod")
-		_, err := os.Stat(current)
-		if err != nil && !os.IsNotExist(err) {
-			return fmt.Errorf("failed to stat go.mod file: %w", err)
-		}
-		if os.IsNotExist(err) {
-			// Move up.
-			prev := dir
-			dir = filepath.Dir(dir)
-			if dir == prev {
-				return fmt.Errorf("could not find go.mod file")
-			}
-			continue
-		}
-		// Found a go.mod file.
-		// Read it and find the templ version.
-		m, err := os.ReadFile(current)
-		if err != nil {
-			return fmt.Errorf("failed to read go.mod file: %w", err)
-		}
-
-		// Replace "go 1.21.x" with "go 1.21".
-		m = patchGoVersion(m)
-
-		mf, err := modfile.Parse(current, m, nil)
-		if err != nil {
-			return fmt.Errorf("failed to parse go.mod file: %w", err)
-		}
-		if mf.Module.Mod.Path == "github.com/a-h/templ" {
-			// The go.mod file is for templ itself.
-			return nil
-		}
-		for _, r := range mf.Require {
-			if r.Mod.Path == "github.com/a-h/templ" {
-				cmp := semver.Compare(r.Mod.Version, templ.Version())
-				if cmp < 0 {
-					return fmt.Errorf("generator %v is newer than templ version %v found in go.mod file, consider running `go get -u github.com/a-h/templ` to upgrade", templ.Version(), r.Mod.Version)
-				}
-				if cmp > 0 {
-					return fmt.Errorf("generator %v is older than templ version %v found in go.mod file, consider upgrading templ CLI", templ.Version(), r.Mod.Version)
-				}
-				return nil
-			}
-		}
-	}
-}

cmd/templ/generatecmd/modcheck/modcheck.go

@@ -0,0 +1,93 @@
+package modcheck
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+
+	"github.com/a-h/templ"
+	"golang.org/x/mod/modfile"
+	"golang.org/x/mod/semver"
+)
+
+// WalkUp the directory tree, starting at dir, until we find a directory containing
+// a go.mod file.
+func WalkUp(dir string) (string, error) {
+	dir, err := filepath.Abs(dir)
+	if err != nil {
+		return "", fmt.Errorf("failed to get absolute path: %w", err)
+	}
+
+	var modFile string
+	for {
+		modFile = filepath.Join(dir, "go.mod")
+		_, err := os.Stat(modFile)
+		if err != nil && !os.IsNotExist(err) {
+			return "", fmt.Errorf("failed to stat go.mod file: %w", err)
+		}
+		if os.IsNotExist(err) {
+			// Move up.
+			prev := dir
+			dir = filepath.Dir(dir)
+			if dir == prev {
+				break
+			}
+			continue
+		}
+		break
+	}
+
+	// No file found.
+	if modFile == "" {
+		return dir, fmt.Errorf("could not find go.mod file")
+	}
+	return dir, nil
+}
+
+// Replace "go 1.21.3" with "go 1.21" until https://github.com/golang/go/issues/61888 is fixed, see templ issue https://github.com/a-h/templ/issues/355
+var goVersionRegexp = regexp.MustCompile(`\ngo (\d+\.\d+)(?:\D.+)\n`)
+
+func patchGoVersion(moduleFileContents []byte) []byte {
+	return goVersionRegexp.ReplaceAll(moduleFileContents, []byte("\ngo $1\n"))
+}
+
+func Check(dir string) error {
+	dir, err := WalkUp(dir)
+	if err != nil {
+		return err
+	}
+
+	// Found a go.mod file.
+	// Read it and find the templ version.
+	modFile := filepath.Join(dir, "go.mod")
+	m, err := os.ReadFile(modFile)
+	if err != nil {
+		return fmt.Errorf("failed to read go.mod file: %w", err)
+	}
+
+	// Replace "go 1.21.x" with "go 1.21".
+	m = patchGoVersion(m)
+
+	mf, err := modfile.Parse(modFile, m, nil)
+	if err != nil {
+		return fmt.Errorf("failed to parse go.mod file: %w", err)
+	}
+	if mf.Module.Mod.Path == "github.com/a-h/templ" {
+		// The go.mod file is for templ itself.
+		return nil
+	}
+	for _, r := range mf.Require {
+		if r.Mod.Path == "github.com/a-h/templ" {
+			cmp := semver.Compare(r.Mod.Version, templ.Version())
+			if cmp < 0 {
+				return fmt.Errorf("generator %v is newer than templ version %v found in go.mod file, consider running `go get -u github.com/a-h/templ` to upgrade", templ.Version(), r.Mod.Version)
+			}
+			if cmp > 0 {
+				return fmt.Errorf("generator %v is older than templ version %v found in go.mod file, consider upgrading templ CLI", templ.Version(), r.Mod.Version)
+			}
+			return nil
+		}
+	}
+	return fmt.Errorf("templ not found in go.mod file, run `go get github.com/a-h/templ to install it`")
+}

cmd/templ/generatecmd/main_test.go → cmd/templ/generatecmd/modcheck/modcheck_test.go

@@ -1,4 +1,4 @@
-package generatecmd
+package modcheck
 
 import (
 	"testing"

cmd/templ/generatecmd/run/run_unix.go

@@ -27,29 +27,20 @@ func KillAll() (err error) {
 	return
 }
 
-func Stop() (err error) {
-	m.Lock()
-	defer m.Unlock()
-	for _, cmd := range running {
-		err := syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
-		if err != nil {
-			return err
-		}
-	}
-	running = map[string]*exec.Cmd{}
-	return
+func Stop(cmd *exec.Cmd) (err error) {
+	return syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
 }
 
 func Run(ctx context.Context, workingDir, input string) (cmd *exec.Cmd, err error) {
+	m.Lock()
+	defer m.Unlock()
 	cmd, ok := running[input]
 	if ok {
-		if err = Stop(); err != nil {
-			return
+		if err = syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL); err != nil {
+			return cmd, err
 		}
 		delete(running, input)
 	}
-	m.Lock()
-	defer m.Unlock()
 	parts := strings.Fields(input)
 	executable := parts[0]
 	args := []string{}

cmd/templ/generatecmd/run/run_windows.go

@@ -30,32 +30,27 @@ func KillAll() (err error) {
 	return
 }
 
-func Stop() (err error) {
+func Stop(cmd *exec.Cmd) (err error) {
+	kill := exec.Command("TASKKILL", "/T", "/F", "/PID", strconv.Itoa(cmd.Process.Pid))
+	kill.Stderr = os.Stderr
+	kill.Stdout = os.Stdout
+	return kill.Run()
+}
+
+func Run(ctx context.Context, workingDir, input string) (cmd *exec.Cmd, err error) {
 	m.Lock()
 	defer m.Unlock()
-	for _, cmd := range running {
+	cmd, ok := running[input]
+	if ok {
 		kill := exec.Command("TASKKILL", "/T", "/F", "/PID", strconv.Itoa(cmd.Process.Pid))
 		kill.Stderr = os.Stderr
 		kill.Stdout = os.Stdout
 		err := kill.Run()
 		if err != nil {
 			return err
 		}
-	}
-	running = map[string]*exec.Cmd{}
-	return
-}
-
-func Run(ctx context.Context, workingDir, input string) (cmd *exec.Cmd, err error) {
-	cmd, ok := running[input]
-	if ok {
-		if err = Stop(); err != nil {
-			return
-		}
 		delete(running, input)
 	}
-	m.Lock()
-	defer m.Unlock()
 	parts := strings.Fields(input)
 	executable := parts[0]
 	args := []string{}

cmd/templ/generatecmd/testwatch/testdata/go.mod.embed

@@ -0,0 +1,7 @@
+module templ/testproject
+
+go 1.21
+
+require github.com/a-h/templ v0.2.513 // indirect
+
+replace github.com/a-h/templ => {moduleRoot}

cmd/templ/generatecmd/testwatch/testdata/go.sum

@@ -0,0 +1,2 @@
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=