feat(process): add stdin service helpers

Co-Authored-By: Virgil <virgil@lethean.io>

global_test.go

@@ -36,6 +36,12 @@ func TestGlobal_DefaultNotInitialized(t *testing.T) {
 	_, err = Output("proc-1")
 	assert.ErrorIs(t, err, ErrServiceNotInitialized)
 
+	err = Input("proc-1", "test")
+	assert.ErrorIs(t, err, ErrServiceNotInitialized)
+
+	err = CloseStdin("proc-1")
+	assert.ErrorIs(t, err, ErrServiceNotInitialized)
+
 	assert.Nil(t, List())
 	assert.Nil(t, Running())
 
@@ -273,6 +279,30 @@ func TestGlobal_Output(t *testing.T) {
 	assert.Contains(t, output, "global-output")
 }
 
+func TestGlobal_InputAndCloseStdin(t *testing.T) {
+	svc, _ := newTestService(t)
+
+	old := defaultService.Swap(svc)
+	defer func() {
+		if old != nil {
+			defaultService.Store(old)
+		}
+	}()
+
+	proc, err := Start(context.Background(), "cat")
+	require.NoError(t, err)
+
+	err = Input(proc.ID, "global-input\n")
+	require.NoError(t, err)
+
+	err = CloseStdin(proc.ID)
+	require.NoError(t, err)
+
+	<-proc.Done()
+
+	assert.Contains(t, proc.Output(), "global-input")
+}
+
 func TestGlobal_Wait(t *testing.T) {
 	svc, _ := newTestService(t)
 

process_global.go

@@ -114,6 +114,32 @@ func Output(id string) (string, error) {
 	return svc.Output(id)
 }
 
+// Input writes data to the stdin of a managed process using the default service.
+//
+// Example:
+//
+//	_ = process.Input("proc-1", "hello\n")
+func Input(id string, input string) error {
+	svc := Default()
+	if svc == nil {
+		return ErrServiceNotInitialized
+	}
+	return svc.Input(id, input)
+}
+
+// CloseStdin closes the stdin pipe of a managed process using the default service.
+//
+// Example:
+//
+//	_ = process.CloseStdin("proc-1")
+func CloseStdin(id string) error {
+	svc := Default()
+	if svc == nil {
+		return ErrServiceNotInitialized
+	}
+	return svc.CloseStdin(id)
+}
+
 // Wait blocks until a managed process exits and returns its final snapshot.
 //
 // Example:

service.go

@@ -536,6 +536,32 @@ func (s *Service) Output(id string) (string, error) {
 	return proc.Output(), nil
 }
 
+// Input writes data to the stdin of a managed process.
+//
+// Example:
+//
+//	_ = svc.Input("proc-1", "hello\n")
+func (s *Service) Input(id string, input string) error {
+	proc, err := s.Get(id)
+	if err != nil {
+		return err
+	}
+	return proc.SendInput(input)
+}
+
+// CloseStdin closes the stdin pipe of a managed process.
+//
+// Example:
+//
+//	_ = svc.CloseStdin("proc-1")
+func (s *Service) CloseStdin(id string) error {
+	proc, err := s.Get(id)
+	if err != nil {
+		return err
+	}
+	return proc.CloseStdin()
+}
+
 // Wait blocks until a managed process exits and returns its final snapshot.
 //
 // Example:

service_test.go

@@ -607,6 +607,57 @@ func TestService_Output(t *testing.T) {
 	})
 }
 
+func TestService_Input(t *testing.T) {
+	t.Run("writes to stdin", func(t *testing.T) {
+		svc, _ := newTestService(t)
+
+		proc, err := svc.Start(context.Background(), "cat")
+		require.NoError(t, err)
+
+		err = svc.Input(proc.ID, "service-input\n")
+		require.NoError(t, err)
+
+		err = svc.CloseStdin(proc.ID)
+		require.NoError(t, err)
+
+		<-proc.Done()
+
+		assert.Contains(t, proc.Output(), "service-input")
+	})
+
+	t.Run("error on unknown id", func(t *testing.T) {
+		svc, _ := newTestService(t)
+
+		err := svc.Input("nonexistent", "test")
+		assert.ErrorIs(t, err, ErrProcessNotFound)
+	})
+}
+
+func TestService_CloseStdin(t *testing.T) {
+	t.Run("closes stdin pipe", func(t *testing.T) {
+		svc, _ := newTestService(t)
+
+		proc, err := svc.Start(context.Background(), "cat")
+		require.NoError(t, err)
+
+		err = svc.CloseStdin(proc.ID)
+		require.NoError(t, err)
+
+		select {
+		case <-proc.Done():
+		case <-time.After(2 * time.Second):
+			t.Fatal("cat should exit when stdin is closed")
+		}
+	})
+
+	t.Run("error on unknown id", func(t *testing.T) {
+		svc, _ := newTestService(t)
+
+		err := svc.CloseStdin("nonexistent")
+		assert.ErrorIs(t, err, ErrProcessNotFound)
+	})
+}
+
 func TestService_Wait(t *testing.T) {
 	t.Run("returns final info on success", func(t *testing.T) {
 		svc, _ := newTestService(t)