add omikuji API server

Author: zaneli

kadai4/zaneli/omikuji/README.md

@@ -0,0 +1,41 @@
+## 課題4
+
+おみくじAPI
+
+### 使い方
+
+ポートを指定しないで起動する。(デフォルト8080ポートが使用される。)
+
+```sh
+go run main.go
+```
+
+ポートを指定して起動する。
+
+```sh
+go run main.go 8081
+```
+
+アクセスする。
+
+```
+> curl --dump-header - "http://localhost:8080/"
+HTTP/1.1 200 OK
+Content-Type: application/json; charset=UTF-8
+Date: Sat, 02 Jun 2018 17:52:03 GMT
+Content-Length: 52
+
+{"result":"吉","date":"2018-06-03T02:52:03+09:00"}
+```
+
+テストを実行する。
+
+```
+> go test ./omikuji
+ok  	_/Users/zaneli/ws/dojo1/kadai4/zaneli/omikuji/omikuji	0.026s
+```
+
+```
+> go test ./omikuji --cover
+ok  	_/Users/zaneli/ws/dojo1/kadai4/zaneli/omikuji/omikuji	0.026s	coverage: 76.2% of statements
+```

kadai4/zaneli/omikuji/main.go

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+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"strconv"
+
+	"./omikuji"
+)
+
+func main() {
+	port := 8080
+	if len(os.Args) > 1 {
+		p, err := strconv.Atoi(os.Args[1])
+		if err != nil {
+			log.Fatal(err)
+		}
+		port = p
+	}
+
+	mux := http.NewServeMux()
+	mux.Handle("/", omikuji.AddCurrentDateTime(http.HandlerFunc(omikuji.Handler)))
+	http.ListenAndServe(fmt.Sprintf(":%d", port), mux)
+}

kadai4/zaneli/omikuji/omikuji/context.go

@@ -0,0 +1,21 @@
+package omikuji
+
+import (
+	"context"
+	"net/http"
+	"time"
+)
+
+type contextKey string
+
+const datetimeContextKey contextKey = "datetime"
+
+// AddCurrentDateTime は Context に現在日時を設定する。
+// refer: https://gocodecloud.com/blog/2016/11/15/simple-golang-http-request-context-example/
+func AddCurrentDateTime(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		date := time.Now().In(time.FixedZone("Asia/Tokyo", 9*60*60))
+		ctx := context.WithValue(r.Context(), datetimeContextKey, date)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}

kadai4/zaneli/omikuji/omikuji/debug.test

@@ -0,0 +1,51 @@
+package omikuji
+
+import (
+	"encoding/json"
+	"math/rand"
+	"net/http"
+	"time"
+)
+
+var 大吉 = "大吉"
+var 中吉 = "中吉"
+var 吉 = "吉"
+var 小吉 = "小吉"
+var 凶 = "凶"
+var 結果 = []string{大吉, 中吉, 吉, 小吉, 凶}
+
+// Result はレスポンスJSONの構造を表す。
+type Result struct {
+	Result string `json:"result"`
+	Date   string `json:"date"`
+}
+
+// Handler はおみくじの結果を返す。
+func Handler(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	v := ctx.Value(datetimeContextKey)
+	if v == nil {
+		v = time.Now()
+	}
+	date, ok := v.(time.Time)
+	if !ok {
+		date = time.Now()
+	}
+
+	var result string
+	if is三が日(date) {
+		result = 大吉
+	} else {
+		rand.Shuffle(len(結果), func(i, j int) {
+			結果[i], 結果[j] = 結果[j], 結果[i]
+		})
+		result = 結果[0]
+	}
+	w.Header().Set("Content-Type", "application/json; charset=UTF-8")
+	json.NewEncoder(w).Encode(Result{Result: result, Date: date.Format(time.RFC3339)})
+}
+
+func is三が日(date time.Time) bool {
+	_, m, d := date.Date()
+	return m == time.January && (d == 1 || d == 2 || d == 3)
+}

kadai4/zaneli/omikuji/omikuji/handler.go

@@ -0,0 +1,110 @@
+package omikuji
+
+import (
+	"context"
+	"encoding/json"
+	"io/ioutil"
+	"math/rand"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+var jst = time.FixedZone("Asia/Tokyo", 9*60*60)
+
+func contains(expecteds []string, actual string) bool {
+	for _, expected := range expecteds {
+		if expected == actual {
+			return true
+		}
+	}
+	return false
+}
+
+func Testランダムに結果を返す(t *testing.T) {
+	s := httptest.NewServer(http.HandlerFunc(Handler))
+	defer s.Close()
+
+	for i := 0; i < 100; i++ {
+		res, err := http.Get(s.URL)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		defer res.Body.Close()
+
+		if res.StatusCode != http.StatusOK {
+			t.Errorf("unexpected status code: %d", res.StatusCode)
+		}
+
+		contentType := res.Header.Get("Content-Type")
+		if contentType != "application/json; charset=UTF-8" {
+			t.Errorf("unexpected content type: %s", contentType)
+		}
+
+		body, err := ioutil.ReadAll(res.Body)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+
+		var result Result
+		if err := json.Unmarshal(body, &result); err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+
+		if !(contains(結果, result.Result)) {
+			t.Errorf("unexpected contents: %s", result.Result)
+		}
+
+		if _, err := time.Parse(time.RFC3339, result.Date); err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+	}
+}
+
+// refer: https://blog.questionable.services/article/testing-http-handlers-go/
+func Test三が日は大吉を返す(t *testing.T) {
+	recorder := httptest.NewRecorder()
+	handler := http.HandlerFunc(Handler)
+	rand.Seed(time.Now().UnixNano())
+
+	days := []int{1, 2, 3}
+	for _, day := range days {
+		for i := 0; i < 100; i++ {
+			date := time.Date(2018, time.January, day, rand.Intn(24), rand.Intn(60), rand.Intn(60), rand.Intn(1e9), jst)
+
+			req, err := http.NewRequest("GET", "/", nil)
+			if err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+			ctx := context.WithValue(req.Context(), datetimeContextKey, date)
+			handler.ServeHTTP(recorder, req.WithContext(ctx))
+
+			if recorder.Code != http.StatusOK {
+				t.Errorf("unexpected status code: %d", recorder.Code)
+			}
+			contentType := recorder.Header().Get("Content-Type")
+			if contentType != "application/json; charset=UTF-8" {
+				t.Errorf("unexpected content type: %s", contentType)
+			}
+
+			body, err := ioutil.ReadAll(recorder.Body)
+			if err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+
+			var result Result
+			if err := json.Unmarshal(body, &result); err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+
+			if !(contains(結果, result.Result)) {
+				t.Errorf("unexpected contents: %s", result.Result)
+			}
+
+			if result.Date != date.Format(time.RFC3339) {
+				t.Errorf("unexpected date: %v", result.Date)
+			}
+		}
+	}
+}