test: add sms_handler tests for SendCode endpoint

Add tests for SMS handler:
- SendCode with valid phone number
- SendCode with invalid phone (returns 400)
- SendCode with missing phone (validation error)
- SendCode when service not configured (returns 503)

Coverage: handler 27.7% → 28.6%

internal/api/handler/sms_handler_test.go

@@ -0,0 +1,107 @@
+package handler_test
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+	"github.com/user-management-system/internal/api/handler"
+	"github.com/user-management-system/internal/cache"
+	"github.com/user-management-system/internal/service"
+)
+
+func setupSMSHandler() (*handler.SMSHandler, *gin.Engine) {
+	gin.SetMode(gin.TestMode)
+
+	l1Cache := cache.NewL1Cache()
+	l2Cache := cache.NewRedisCache(false)
+	cacheManager := cache.NewCacheManager(l1Cache, l2Cache)
+
+	// Create mock SMS provider
+	mockProvider := &service.MockSMSProvider{}
+	smsConfig := service.DefaultSMSCodeConfig()
+	smsCodeSvc := service.NewSMSCodeService(mockProvider, cacheManager, smsConfig)
+
+	// Create handler with nil authService (for SendCode tests)
+	h := handler.NewSMSHandler(nil, smsCodeSvc)
+
+	router := gin.New()
+	router.POST("/api/v1/sms/send", h.SendCode)
+
+	return h, router
+}
+
+func TestSMSHandler_SendCode(t *testing.T) {
+	_, router := setupSMSHandler()
+
+	tests := []struct {
+		name       string
+		body       map[string]interface{}
+		wantStatus int
+		wantCode   float64
+	}{
+		{
+			name:       "valid phone",
+			body:       map[string]interface{}{"phone": "13800138000", "purpose": "login"},
+			wantStatus: http.StatusOK,
+			wantCode:   0,
+		},
+		{
+			name:       "invalid phone",
+			body:       map[string]interface{}{"phone": "invalid", "purpose": "login"},
+			wantStatus: http.StatusBadRequest, // Handler returns 400 for invalid phone
+			wantCode:   400,
+		},
+		{
+			name:       "missing phone",
+			body:       map[string]interface{}{"purpose": "login"},
+			wantStatus: http.StatusBadRequest,
+			wantCode:   400,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			body, _ := json.Marshal(tt.body)
+			w := httptest.NewRecorder()
+			req, _ := http.NewRequest("POST", "/api/v1/sms/send", bytes.NewBuffer(body))
+			req.Header.Set("Content-Type", "application/json")
+			router.ServeHTTP(w, req)
+
+			assert.Equal(t, tt.wantStatus, w.Code)
+
+			var resp map[string]interface{}
+			if err := json.Unmarshal(w.Body.Bytes(), &resp); err == nil {
+				if tt.wantCode == 0 {
+					assert.Equal(t, float64(0), resp["code"])
+				}
+			}
+		})
+	}
+}
+
+func TestSMSHandler_SendCode_ServiceNotConfigured(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	// Handler with nil smsCodeService
+	h := handler.NewSMSHandler(nil, nil)
+
+	router := gin.New()
+	router.POST("/api/v1/sms/send", h.SendCode)
+
+	body, _ := json.Marshal(map[string]interface{}{"phone": "13800138000", "purpose": "login"})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest("POST", "/api/v1/sms/send", bytes.NewBuffer(body))
+	req.Header.Set("Content-Type", "application/json")
+	router.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusServiceUnavailable, w.Code)
+
+	var resp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &resp)
+	assert.Equal(t, float64(503), resp["code"])
+}