watch: handle SIGHUP in watcher interrupt path

watch.go

@@ -154,9 +154,10 @@ func isContextError(err error) bool {
 
 func closeOnInterrupt(w *fsnotify.Watcher) {
 	ch := make(chan os.Signal, 1)
-	signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
+	signal.Notify(ch, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP)
 	go func() {
 		<-ch
+		signal.Stop(ch)
 		w.Close()
 		os.Exit(0)
 	}()

watch_interrupt_test.go

@@ -0,0 +1,95 @@
+//go:build watch && !windows
+// +build watch,!windows
+
+package task_test
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestWatchProcessExitsOnSIGHUP(t *testing.T) {
+	taskPath, err := findTaskBinaryForWatchTest()
+	if err != nil {
+		t.Skipf("skipping watcher signal test: %v", err)
+	}
+
+	dir := t.TempDir()
+	if err := os.MkdirAll(filepath.Join(dir, "src"), 0o755); err != nil {
+		t.Fatalf("mkdir src: %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "src", "a.txt"), []byte("x"), 0o644); err != nil {
+		t.Fatalf("write seed source: %v", err)
+	}
+
+	taskfile := `version: '3'
+
+tasks:
+  default:
+    watch: true
+    sources:
+      - src/**/*
+    cmds:
+      - echo "watch run"`
+	if err := os.WriteFile(filepath.Join(dir, "Taskfile.yml"), []byte(taskfile), 0o644); err != nil {
+		t.Fatalf("write taskfile: %v", err)
+	}
+
+	var out bytes.Buffer
+	sut := exec.Command(taskPath, "--watch", "default")
+	sut.Stdout = &out
+	sut.Stderr = &out
+	sut.Dir = dir
+	if err := sut.Start(); err != nil {
+		t.Fatalf("start task watcher process: %v", err)
+	}
+
+	if err := waitForOutputContains(&out, "Started watching for tasks: default", 5*time.Second); err != nil {
+		_ = sut.Process.Kill()
+		_, _ = sut.Process.Wait()
+		t.Fatalf("watch process did not reach ready state: %v\noutput:\n%s", err, out.String())
+	}
+
+	if err := sut.Process.Signal(syscall.SIGHUP); err != nil {
+		_ = sut.Process.Kill()
+		_, _ = sut.Process.Wait()
+		t.Fatalf("send SIGHUP to watch process: %v", err)
+	}
+
+	done := make(chan error, 1)
+	go func() { done <- sut.Wait() }()
+
+	select {
+	case err := <-done:
+		if err != nil {
+			t.Fatalf("watch process exit after SIGHUP: %v\noutput:\n%s", err, out.String())
+		}
+	case <-time.After(5 * time.Second):
+		_ = sut.Process.Kill()
+		t.Fatalf("watch process did not exit after SIGHUP\noutput:\n%s", out.String())
+	}
+}
+
+func findTaskBinaryForWatchTest() (string, error) {
+	if info, err := os.Stat("./bin/task"); err == nil {
+		return info.Name(), nil
+	}
+	return exec.LookPath("task")
+}
+
+func waitForOutputContains(out *bytes.Buffer, needle string, timeout time.Duration) error {
+	deadline := time.Now().Add(timeout)
+	for time.Now().Before(deadline) {
+		if strings.Contains(out.String(), needle) {
+			return nil
+		}
+		time.Sleep(25 * time.Millisecond)
+	}
+	return os.ErrDeadlineExceeded
+}