update mock and add register sensor test

internal/domains/sensors/service_test.go

@@ -0,0 +1,79 @@
+package sensors
+
+import (
+	"testing"
+	"time"
+
+	"go.uber.org/mock/gomock"
+)
+
+func setup(t *testing.T) (*Service, *MockRepository) {
+	ctrl := gomock.NewController(t)
+	q := NewMockRepository(ctrl)
+	s := NewService(q)
+	return s, q
+}
+
+func Test_RegisterSensor(t *testing.T) {
+	type testCase struct {
+		name      string
+		given     Sensor
+		setupMock func(q *MockRepository, params Sensor)
+		expecErr  bool
+	}
+
+	tests := []testCase{
+		{
+			name: "success - registers new sensor",
+			given: Sensor{
+				SensorID:         "temp-001",
+				SensorType:       Temperature,
+				SamplingInterval: ptr(time.Minute),
+				ThresholdAbove:   ptr(100.0),
+				ThresholdBelow:   ptr(0.0),
+			},
+			setupMock: func(q *MockRepository, params Sensor) {
+				q.EXPECT().CreateSensor(params).Return(nil)
+			},
+			expecErr: false,
+		},
+		{
+			name: "error - sensor already exists",
+			given: Sensor{
+				SensorID:         "temp-001",
+				SensorType:       Temperature,
+				SamplingInterval: ptr(time.Minute),
+				ThresholdAbove:   ptr(100.0),
+				ThresholdBelow:   ptr(0.0),
+			},
+			setupMock: func(q *MockRepository, params Sensor) {
+				q.EXPECT().CreateSensor(params).Return(ErrSensorAlreadyExists)
+			},
+			expecErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s, q := setup(t)
+
+			tt.setupMock(q, tt.given)
+
+			err := s.RegisterSensor(tt.given)
+
+			if tt.expecErr && err == nil {
+				t.Error("expected error, got nil")
+				return
+			}
+
+			if !tt.expecErr && err != nil {
+				t.Errorf("expected no error, got %v", err)
+				return
+			}
+
+			if tt.expecErr && err != ErrSensorAlreadyExists {
+				t.Errorf("expected ErrSensorAlreadyExists, got %v", err)
+			}
+		})
+	}
+}