Update1

precode.go

@@ -46,13 +46,10 @@ func mainHandle(w http.ResponseWriter, req *http.Request) {
     w.Write([]byte(answer))
 }
 
-func TestMainHandlerWhenCountMoreThanTotal(t *testing.T) {
-    totalCount := 4
-    req := ... // здесь нужно создать запрос к сервису
-
-    responseRecorder := httptest.NewRecorder()
-    handler := http.HandlerFunc(mainHandle)
-    handler.ServeHTTP(responseRecorder, req)
-
-    // здесь нужно добавить необходимые проверки
+func main() {
+	http.HandleFunc("/cafe", mainHandle)
+	err := http.ListenAndServe(":8080", nil)
+	if err != nil {
+		panic(err)
+	}
 }

precode_test.go

@@ -0,0 +1,48 @@
+package tests
+
+import (
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+// Проверка статуса ответа и тела ответа
+func TestMainHandler_StatusOkAndBodyNotEmpty(t *testing.T) {
+	req := httptest.NewRequest("GET", "/cafe?count=2&city=moscow", nil)
+
+	responseRecorder := httptest.NewRecorder()
+	handler := http.HandlerFunc(mainHandle)
+	handler.ServeHTTP(responseRecorder, req)
+
+	assert.Equal(t, http.StatusOK, responseRecorder.Code)
+	assert.NotEmpty(t, responseRecorder.Body.String())
+}
+// Проверка неподдерживаемого города
+func TestMainHandlerWrongCity(t *testing.T) {
+	req := httptest.NewRequest("GET", "/cafe?count=2&city=spb", nil)
+
+	responseRecorder := httptest.NewRecorder()
+	handler := http.HandlerFunc(mainHandle)
+	handler.ServeHTTP(responseRecorder, req)
+
+	require.Equal(t, http.StatusBadRequest, responseRecorder.Code)
+	assert.Contains(t, responseRecorder.Body.String(), "wrong city value")
+}
+// Проверка количества кафе
+func TestMainHandler_WhenCountMoreThanTotal(t *testing.T) {
+	totalCount := 4
+	req := httptest.NewRequest("GET", "/cafe?count=100&city=moscow", nil)
+
+	responseRecorder := httptest.NewRecorder()
+	handler := http.HandlerFunc(mainHandle)
+	handler.ServeHTTP(responseRecorder, req)
+
+	checkCafeString := "Мир кофе,Сладкоежка,Кофе и завтраки,Сытый студент"
+
+	list := strings.Split(responseRecorder.Body.String(), ",")
+
+	assert.GreaterOrEqual(t, totalCount, (len(list)))
+	assert.Equal(t, responseRecorder.Body.String(), checkCafeString)
+}