first test

go.mod

@@ -0,0 +1,11 @@
+module main.go
+
+go 1.20
+
+require github.com/stretchr/testify v1.9.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,10 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+var cafeList = map[string][]string{
+	"moscow": []string{"Мир кофе", "Сладкоежка", "Кофе и завтраки", "Сытый студент"},
+}
+
+func mainHandle(w http.ResponseWriter, req *http.Request) {
+	countStr := req.URL.Query().Get("count")
+	if countStr == "" {
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte("count missing"))
+		return
+	}
+
+	count, err := strconv.Atoi(countStr)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte("wrong count value"))
+		return
+	}
+
+	city := req.URL.Query().Get("city")
+
+	cafe, ok := cafeList[city]
+	if !ok {
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte("wrong city value"))
+		return
+	}
+
+	if count > len(cafe) {
+		count = len(cafe)
+	}
+
+	answer := strings.Join(cafe[:count], ",")
+
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte(answer))
+}
+
+func main() {
+	http.HandleFunc(`/cafe`, mainHandle)
+	err := http.ListenAndServe(":8080", nil)
+	if err != nil {
+		panic(err)
+	}
+}

main_test.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMainHandlerWhenAllRight(t *testing.T) {
+	req := httptest.NewRequest("GET", "/cafe?count=4&city=moscow", nil)
+	responseRecorder := httptest.NewRecorder()
+	handler := http.HandlerFunc(mainHandle)
+	handler.ServeHTTP(responseRecorder, req)
+
+	status := responseRecorder.Code
+	body := responseRecorder.Body
+	require.Equal(t, http.StatusOK, status)
+	assert.NotEmpty(t, body)
+}
+
+func TestMainHandWrongCity(t *testing.T) {
+	req := httptest.NewRequest("GET", "/cafe?count=4&city=mocsow", nil)
+	responseRecorder := httptest.NewRecorder()
+	handler := http.HandlerFunc(mainHandle)
+	handler.ServeHTTP(responseRecorder, req)
+
+	status := responseRecorder.Code
+	body := responseRecorder.Body.String()
+	require.Equal(t, http.StatusBadRequest, status)
+	assert.Equal(t, "wrong city value", body)
+}
+
+func TestMainHandlerWhenCountMoreThanTotal(t *testing.T) {
+	totalCount := 4
+	req := httptest.NewRequest("GET", "/cafe?count=10&city=moscow", nil)
+	responseRecorder := httptest.NewRecorder()
+	handler := http.HandlerFunc(mainHandle)
+	handler.ServeHTTP(responseRecorder, req)
+
+	require.NotEmpty(t, responseRecorder.Code)
+
+	status := responseRecorder.Code
+	require.Equal(t, http.StatusOK, status)
+
+	body := responseRecorder.Body.String()
+	list := strings.Split(body, ",")
+	assert.Equal(t, totalCount, len(list))
+}