add chunked http response

README.md

@@ -94,4 +94,14 @@ You can also redirect to a 'file://' protol address:
 
 ```bash
 curl -v 'localhost:9527/redirect/301?url=file:///etc/passwd'
-```
+```
+### :arrows_counterclockwise: Chunked http response
+
+You can simulate chunked http response. Use the following format, `$COUNT` is the count of chunked message. 
+
+`http://localhost:9527/chunk/$COUNT`
+
+Examples:
+
+* http://localhost:9527/chunk/3
+* http://localhost:9527/chunk/999

main.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"html/template"
 	"log"
+	"math/rand"
 	"mime"
 	"net/http"
 	"net/http/httputil"
@@ -178,6 +179,36 @@ func sizeHandler(w http.ResponseWriter, r *http.Request) {
 	fmt.Fprint(w, strings.Repeat("o", size))
 }
 
+func chunkHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+
+	count, _ := strconv.Atoi(vars["count"])
+
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Transfer-Encoding", "chunked")
+
+	//time.Sleep(time.Duration(count) * time.Second)
+	for i := 0; i < count; i++ {
+		randomStr := randomString(10)
+		currentTime := time.Now().Format(time.RFC3339)
+		fmt.Fprintf(w, "Time: %s, Msg: %s\n", currentTime, randomStr)
+		if f, ok := w.(http.Flusher); ok {
+			f.Flush()
+		}
+		time.Sleep(1 * time.Second)
+	}
+}
+
+func randomString(n int) string {
+	var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+
+	s := make([]rune, n)
+	for i := range s {
+		s[i] = letters[rand.Intn(len(letters))]
+	}
+	return string(s)
+}
+
 func appRouter() http.Handler {
 	r := mux.NewRouter()
 	r.HandleFunc("/", indexHandler)
@@ -187,6 +218,7 @@ func appRouter() http.Handler {
 	r.HandleFunc("/slow/{time:[0-9]+}", slowHandler)
 	r.HandleFunc("/redirect/{method}", redirectHandler)
 	r.HandleFunc("/size/{size:[0-9]+}{measure:[k|m]?}{ext:.*}", sizeHandler)
+	r.HandleFunc("/chunk/{count:[0-9]+}", chunkHandler)
 	return r
 }
 

main_test.go

@@ -1,12 +1,15 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/gorilla/mux"
 )
 
 func TestIndexHandler(t *testing.T) {
@@ -21,7 +24,7 @@ func TestIndexHandler(t *testing.T) {
 	if w.Code != http.StatusOK {
 		t.Errorf("Got HTTP status code %d, expect 200", w.Code)
 	}
-	if !strings.Contains(w.Body.String(), "SERVER-ID") {
+	if !strings.Contains(w.Body.String(), "Server id:") {
 		t.Errorf("Got HTTP status code %d, expect 200", w.Code)
 	}
 }
@@ -134,3 +137,55 @@ func TestSlowHandler(t *testing.T) {
 
 	}
 }
+
+// generate test for chunkHandler
+func TestChunkHandler(t *testing.T) {
+	// 创建一个路由，模拟实际的路由行为
+	r := mux.NewRouter()
+	r.HandleFunc("/chunk/{count}", chunkHandler)
+
+	// 创建一个测试服务器
+	server := httptest.NewServer(r)
+	defer server.Close()
+
+	expectedCount := 5
+	url := fmt.Sprintf("%s/chunk/%d", server.URL, expectedCount)
+	// 发送请求到测试服务器
+	resp, err := http.Get(url)
+	if err != nil {
+		t.Fatalf("Failed to send request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	// 检查Transfer-Encoding是否为chunked
+	if resp.TransferEncoding == nil || resp.TransferEncoding[0] != "chunked" {
+		t.Errorf("Expected chunked transfer encoding, got %v", resp.TransferEncoding)
+	}
+
+	// 读取响应体，确保它是分多次接收的
+	scanner := bufio.NewScanner(resp.Body)
+	lineCount := 0
+
+	last_time := time.Now()
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.Contains(line, "Time:") && strings.Contains(line, "Msg:") {
+			lineCount++
+			// 检查每个分块之间的时间间隔是否大于1秒
+			if lineCount > 1 {
+				current_time := time.Now()
+				if current_time.Sub(last_time) < 1*time.Second {
+					t.Errorf("Chunk interval is less than 1 second")
+				}
+			}
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		t.Fatalf("Error reading stream: %v", err)
+	}
+	// 确保我们接收到了预期数量的分块
+	if lineCount != expectedCount {
+		t.Errorf("Expected %d chunks, got %d", expectedCount, lineCount)
+	}
+}