// server.go
package main
import (
"encoding/json"
"fmt"
"net/http"
)
// PlayerStore stores score information about players
type PlayerStore interface {
GetPlayerScore(name string) int
RecordWin(name string)
GetLeague() []Player
}
// Player stores a name with a number of wins
type Player struct {
Name string
Wins int
}
// PlayerServer is a HTTP interface for player information
type PlayerServer struct {
store PlayerStore
http.Handler
}
const jsonContentType = "application/json"
// NewPlayerServer creates a PlayerServer with routing configured
func NewPlayerServer(store PlayerStore) *PlayerServer {
p := new(PlayerServer)
p.store = store
router := http.NewServeMux()
router.Handle("/league", http.HandlerFunc(p.leagueHandler))
router.Handle("/players/", http.HandlerFunc(p.playersHandler))
p.Handler = router
return p
}
func (p *PlayerServer) leagueHandler(w http.ResponseWriter, r *http.Request) {
json.NewEncoder(w).Encode(p.store.GetLeague())
w.Header().Set("content-type", jsonContentType)
w.WriteHeader(http.StatusOK)
}
func (p *PlayerServer) playersHandler(w http.ResponseWriter, r *http.Request) {
player := r.URL.Path[len("/players/"):]
switch r.Method {
case http.MethodPost:
p.processWin(w, player)
case http.MethodGet:
p.showScore(w, player)
}
}
func (p *PlayerServer) showScore(w http.ResponseWriter, player string) {
score := p.store.GetPlayerScore(player)
if score == 0 {
w.WriteHeader(http.StatusNotFound)
}
fmt.Fprint(w, score)
}
func (p *PlayerServer) processWin(w http.ResponseWriter, player string) {
p.store.RecordWin(player)
w.WriteHeader(http.StatusAccepted)
}
// InMemoryPlayerStore.go
package main
func NewInMemoryPlayerStore() *InMemoryPlayerStore {
return &InMemoryPlayerStore{map[string]int{}}
}
type InMemoryPlayerStore struct {
store map[string]int
}
func (i *InMemoryPlayerStore) GetLeague() []Player {
var league []Player
for name, wins := range i.store {
league = append(league, Player{name, wins})
}
return league
}
func (i *InMemoryPlayerStore) RecordWin(name string) {
i.store[name]++
}
func (i *InMemoryPlayerStore) GetPlayerScore(name string) int {
return i.store[name]
}
// main.go
package main
import (
"log"
"net/http"
)
func main() {
server := NewPlayerServer(NewInMemoryPlayerStore())
if err := http.ListenAndServe(":5000", server); err != nil {
log.Fatalf("could not listen on port 5000 %v", err)
}
}
# github.com/quii/learn-go-with-tests/json-and-io/v7
./FileSystemStore_test.go:15:28: too many values in struct initializer
./FileSystemStore_test.go:17:15: store.GetLeague undefined (type FileSystemStore has no field or method GetLeague)
func (f *FileSystemPlayerStore) GetPlayerScore(name string) int {
var wins int
for _, player := range f.GetLeague() {
if player.Name == name {
wins = player.Wins
break
}
}
return wins
}
type FileSystemPlayerStore struct {
database io.ReadWriteSeeker
}
查看是否通过编译
./FileSystemStore_test.go:15:34: cannot use database (type *strings.Reader) as type io.ReadWriteSeeker in field value:
*strings.Reader does not implement io.ReadWriteSeeker (missing Write method)
./FileSystemStore_test.go:36:34: cannot use database (type *strings.Reader) as type io.ReadWriteSeeker in field value:
*strings.Reader does not implement io.ReadWriteSeeker (missing Write method)
func (f *FileSystemPlayerStore) RecordWin(name string) {
league := f.GetLeague()
for i, player := range league {
if player.Name == name {
league[i].Wins++
}
}
f.database.Seek(0,0)
json.NewEncoder(f.database).Encode(league)
}
你可能会问，为什么我要用 league[i].Wins++ 而不是 player.Wins++。
当你在一个切片上取值时，将返回当前循环的索引（我们示例中的 i）和该索引中的元素的副本。更改副本 Wins 的值不会对我们迭代的 league 产生任何影响。因此，我们需要通过使用 league[i] 来获取对实际值的引用，然后更改该值。
./main.go:18:35: multiple-value NewFileSystemPlayerStore() in single-value context
./FileSystemStore_test.go:35:36: multiple-value NewFileSystemPlayerStore() in single-value context
./FileSystemStore_test.go:57:36: multiple-value NewFileSystemPlayerStore() in single-value context
./FileSystemStore_test.go:70:36: multiple-value NewFileSystemPlayerStore() in single-value context
./FileSystemStore_test.go:85:36: multiple-value NewFileSystemPlayerStore() in single-value context
./server_integration_test.go:12:35: multiple-value NewFileSystemPlayerStore() in single-value context
在 main 中，我们要退出程序，打印错误。
store, err := NewFileSystemPlayerStore(db)
if err != nil {
log.Fatalf("problem creating file system player store, %v ", err)
}
在测试中，我们应该断言没有错误。我们可以编写辅助函数来协助处理。
func assertNoError(t *testing.T, err error) {
t.Helper()
if err != nil {
t.Fatalf("didnt expect an error but got one, %v", err)
}
}
使用这个辅助函数处理其他编译问题。最后，你应该得到一个失败的测试。
=== RUN TestRecordingWinsAndRetrievingThem
--- FAIL: TestRecordingWinsAndRetrievingThem (0.00s)
server_integration_test.go:14: didnt expect an error but got one, problem loading player store from file /var/folders/nj/r_ccbj5d7flds0sf63yy4vb80000gn/T/db841037437, problem parsing league, EOF
=== RUN TestFileSystemStore/works_with_an_empty_file
--- FAIL: TestFileSystemStore/works_with_an_empty_file (0.00s)
FileSystemStore_test.go:108: didnt expect an error but got one, problem loading player store from file /var/folders/nj/r_ccbj5d7flds0sf63yy4vb80000gn/T/db019548018, problem parsing league, EOF
编写足够的代码使测试通过
将构造函数更改为以下内容
func NewFileSystemPlayerStore(file *os.File) (*FileSystemPlayerStore, error) {
file.Seek(0, 0)
info, err := file.Stat()
if err != nil {
return nil, fmt.Errorf("problem getting file info from file %s, %v", file.Name(), err)
}
if info.Size()==0 {
file.Write([]byte("[]"))
file.Seek(0, 0)
}
league, err := NewLeague(file)
if err != nil {
return nil, fmt.Errorf("problem loading player store from file %s, %v", file.Name(), err)
}
return &FileSystemPlayerStore{
database:&tape{file},
league:league,
}, nil
}
