launchd: implement 'Stop()' function

Implement and test the 'Stop()' function for the 'launchd' daemon manager.
'Stop()' shuts down the specified service (if it is running) with 'launchctl
kill SIGINT'. If the command succeeds *or* fails indicating the service is
not bootstrapped, exit without an error; otherwise, report the appropriate
error.

Signed-off-by: Victoria Dye <[email protected]>

Author: vdye

internal/daemon/launchd.go

@@ -184,5 +184,22 @@ func (l *launchd) Start(label string) error {
 }
 
 func (l *launchd) Stop(label string) error {
-	return fmt.Errorf("not implemented")
+	user, err := l.user.CurrentUser()
+	if err != nil {
+		return fmt.Errorf("could not get current user for launchd service: %w", err)
+	}
+
+	domainTarget := fmt.Sprintf(domainFormat, user.Uid)
+	serviceTarget := fmt.Sprintf("%s/%s", domainTarget, label)
+	exitCode, err := l.cmdExec.Run("launchctl", "kill", "SIGINT", serviceTarget)
+	if err != nil {
+		return err
+	}
+
+	// Don't throw an error if the service hasn't been bootstrapped
+	if exitCode != 0 && exitCode != LaunchdServiceNotFoundErrorCode {
+		return fmt.Errorf("'launchctl kill' exited with status %d", exitCode)
+	}
+
+	return nil
 }

internal/daemon/launchd_test.go

@@ -258,3 +258,58 @@ func TestLaunchd_Start(t *testing.T) {
 	})
 }
 
+func TestLaunchd_Stop(t *testing.T) {
+	// Set up mocks
+	testUser := &user.User{
+		Uid:      "123",
+		Username: "testuser",
+	}
+	testUserProvider := &mockUserProvider{}
+	testUserProvider.On("CurrentUser").Return(testUser, nil)
+
+	testCommandExecutor := &mockCommandExecutor{}
+
+	launchd := daemon.NewLaunchdProvider(testUserProvider, testCommandExecutor, nil)
+
+	// Test #1: launchctl succeeds
+	t.Run("Calls correct launchctl command", func(t *testing.T) {
+		testCommandExecutor.On("Run",
+			"launchctl",
+			[]string{"kill", "SIGINT", fmt.Sprintf("gui/123/%s", basicDaemonConfig.Label)},
+		).Return(0, nil).Once()
+
+		err := launchd.Stop(basicDaemonConfig.Label)
+		assert.Nil(t, err)
+		mock.AssertExpectationsForObjects(t, testCommandExecutor)
+	})
+
+	// Reset the mock structure between tests
+	testCommandExecutor.Mock = mock.Mock{}
+
+	// Test #2: launchctl fails with uncaught error
+	t.Run("Returns error when launchctl fails", func(t *testing.T) {
+		testCommandExecutor.On("Run",
+			mock.AnythingOfType("string"),
+			mock.AnythingOfType("[]string"),
+		).Return(1, nil).Once()
+
+		err := launchd.Stop(basicDaemonConfig.Label)
+		assert.NotNil(t, err)
+		mock.AssertExpectationsForObjects(t, testCommandExecutor)
+	})
+
+	// Reset the mock structure between tests
+	testCommandExecutor.Mock = mock.Mock{}
+
+	// Test #3: launchctl fails with uncaught error
+	t.Run("Exits without error if service not found", func(t *testing.T) {
+		testCommandExecutor.On("Run",
+			mock.AnythingOfType("string"),
+			mock.AnythingOfType("[]string"),
+		).Return(daemon.LaunchdServiceNotFoundErrorCode, nil).Once()
+
+		err := launchd.Stop(basicDaemonConfig.Label)
+		assert.Nil(t, err)
+		mock.AssertExpectationsForObjects(t, testCommandExecutor)
+	})
+}