kadai4 tk3fftk

kadai4/tk3fftk/README.md

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+## おみくじAPIを作ってみよう
+### 制約
+- [x] JSON形式でおみくじの結果を返す
+- [x] 正月（1/1-1/3）だけ大吉にする
+  - テストにて動作確認しています
+- [x] ハンドラのテストを書いてみる
+
+### 使い方
+```
+$ go build -o lot
+$ ./lot &
+$ curl localhost:8080/lot
+{"result":"大凶"}
+```

kadai4/tk3fftk/main.go

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+package main
+
+import (
+	"net/http"
+
+	"github.com/gopherdojo/dojo3/kadai4/tk3fftk/omikuji"
+)
+
+func main() {
+	handler := omikuji.New(nil)
+	http.Handle("/lot", &handler)
+	http.ListenAndServe(":8080", nil)
+}

kadai4/tk3fftk/omikuji/handler.go

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+package omikuji
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+const bigLuckey = "大吉"
+
+type response struct {
+	Result string `json:"result"`
+}
+
+type Clock interface {
+	Now() time.Time
+}
+
+type ClockFunc func() time.Time
+
+func (f ClockFunc) Now() time.Time {
+	return f()
+}
+
+type OmikujiHandler struct {
+	Clock   Clock
+	Omikuji Omikuji
+}
+
+func New(clock Clock) OmikujiHandler {
+	o := NewOmikuji()
+	return OmikujiHandler{
+		Clock:   clock,
+		Omikuji: o,
+	}
+}
+
+func (o *OmikujiHandler) createResponseJSON(result string) (string, error) {
+	res := &response{Result: result}
+	var buf bytes.Buffer
+	enc := json.NewEncoder(&buf)
+	if err := enc.Encode(res); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
+
+func (o *OmikujiHandler) handlerFunc(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+
+	var res string
+	var err error
+
+	if o.isNewYear() {
+		res, err = o.createResponseJSON(bigLuckey)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+	} else {
+		lot := o.Omikuji.Do([]string{})
+		res, err = o.createResponseJSON(lot)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+	}
+	fmt.Fprintf(w, res)
+}
+
+func (o *OmikujiHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	o.handlerFunc(w, r)
+}
+
+func (o *OmikujiHandler) now() time.Time {
+	if o.Clock == nil {
+		return time.Now()
+	}
+	return o.Clock.Now()
+}
+
+func (o *OmikujiHandler) isNewYear() bool {
+	_, m, d := o.now().Date()
+	if m == 1 && d <= 3 {
+		return true
+	}
+	return false
+}

kadai4/tk3fftk/omikuji/handler_test.go

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+package omikuji
+
+import (
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestIsNewYear(t *testing.T) {
+	cases := map[string]struct {
+		month    int
+		day      int
+		expected bool
+	}{
+		"December31st": {
+			12,
+			31,
+			false,
+		},
+		"January1st": {
+			1,
+			1,
+			true,
+		},
+		"January2nd": {
+			1, 2, true,
+		},
+		"January3rd": {
+			1, 3, true,
+		},
+		"January4th": {
+			1, 4, false,
+		},
+	}
+
+	for k, v := range cases {
+		k := k
+		v := v
+
+		t.Run(k, func(t *testing.T) {
+			t.Helper()
+			handler := New(
+				ClockFunc(func() time.Time {
+					return time.Date(2018, time.Month(v.month), v.day, 6, 0, 0, 0, time.Local)
+				}),
+			)
+
+			if handler.isNewYear() != v.expected {
+				t.Errorf("expected=%v, actual=%v", v.expected, !v.expected)
+			}
+		})
+	}
+}
+
+func TestCreateResponseJSON(t *testing.T) {
+	handler := New(nil)
+	result := "test"
+	expected := "{\"result\":\"test\"}\n"
+	json, err := handler.createResponseJSON(result)
+	if err != nil {
+		t.Fatal("should not come here")
+	}
+	if strings.Compare(json, expected) != 0 {
+		t.Errorf("expected='%v', actual='%v'", expected, json)
+	}
+}
+
+func TestHandler(t *testing.T) {
+	handler := New(ClockFunc(func() time.Time {
+		return time.Date(2018, 1, 1, 6, 0, 0, 0, time.Local)
+	}))
+
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest("GET", "/", nil)
+	handler.handlerFunc(w, r)
+	rw := w.Result()
+	defer rw.Body.Close()
+
+	if rw.StatusCode != http.StatusOK {
+		t.Fatal("unexpected status code")
+	}
+
+	b, err := ioutil.ReadAll(rw.Body)
+	if err != nil {
+		t.Fatal("unexpected error")
+	}
+	expected := "{\"result\":\"大吉\"}\n"
+
+	if s := string(b); s != expected {
+		t.Errorf("expected='%v', actual='%v'", expected, s)
+	}
+}

kadai4/tk3fftk/omikuji/omikuji.go

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+package omikuji
+
+import (
+	"math/rand"
+	"time"
+)
+
+var defaultLots = []string{
+	"大吉",
+	"吉",
+	"中吉",
+	"小吉",
+	"凶",
+	"大凶",
+}
+
+type Omikuji struct {
+	rand *rand.Rand
+}
+
+func NewOmikuji() Omikuji {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	return Omikuji{
+		rand: r,
+	}
+}
+
+func (o *Omikuji) Do(lots []string) string {
+	l := len(lots)
+	if l != 0 {
+		return lots[rand.Intn(l)]
+	}
+
+	return defaultLots[rand.Intn(len(defaultLots))]
+}

kadai4/tk3fftk/omikuji/omikuji_test.go

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+package omikuji
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestOmikuji_Do(t *testing.T) {
+	cases := map[string][]string{
+		"default": defaultLots,
+		"one":     {"大吉"},
+		"two":     {"大吉", "大凶"},
+	}
+
+	o := NewOmikuji()
+
+	for c := range cases {
+		c := c
+		t.Run(c, func(t *testing.T) {
+			t.Helper()
+
+			lots := cases[c]
+			lot := o.Do(lots)
+			for _, l := range lots {
+				if strings.Compare(lot, l) == 0 {
+					return
+				}
+			}
+			t.Errorf("%v should be included in %v", lot, lots)
+		})
+	}
+}