feat: add rest.WithSSE to build SSE route easier (#4729)

rest/engine.go

@@ -15,6 +15,7 @@ import (
 	"github.com/zeromicro/go-zero/rest/handler"
 	"github.com/zeromicro/go-zero/rest/httpx"
 	"github.com/zeromicro/go-zero/rest/internal"
+	"github.com/zeromicro/go-zero/rest/internal/header"
 	"github.com/zeromicro/go-zero/rest/internal/response"
 )
 
@@ -54,6 +55,9 @@ func newEngine(c RestConf) *engine {
 }
 
 func (ng *engine) addRoutes(r featuredRoutes) {
+	if r.sse {
+		r.routes = buildSSERoutes(r.routes)
+	}
 	ng.routes = append(ng.routes, r)
 
 	// need to guarantee the timeout is the max of all routes
@@ -63,6 +67,20 @@ func (ng *engine) addRoutes(r featuredRoutes) {
 	}
 }
 
+func buildSSERoutes(routes []Route) []Route {
+	for i, route := range routes {
+		h := route.Handler
+		routes[i].Handler = func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set(header.ContentType, header.ContentTypeEventStream)
+			w.Header().Set(header.CacheControl, header.CacheControlNoCache)
+			w.Header().Set(header.Connection, header.ConnectionKeepAlive)
+			h(w, r)
+		}
+	}
+
+	return routes
+}
+
 func (ng *engine) appendAuthHandler(fr featuredRoutes, chn chain.Chain,
 	verifier func(chain.Chain) chain.Chain) chain.Chain {
 	if fr.jwt.enabled {

rest/httpc/requests.go

@@ -105,7 +105,7 @@ func buildRequest(ctx context.Context, method, url string, data any) (*http.Requ
 	req.URL.RawQuery = buildFormQuery(u, val[formKey])
 	fillHeader(req, val[headerKey])
 	if hasJsonBody {
-		req.Header.Set(header.ContentType, header.JsonContentType)
+		req.Header.Set(header.ContentType, header.ContentTypeJson)
 	}
 
 	return req, nil

rest/httpc/requests_test.go

@@ -45,7 +45,7 @@ func TestDoRequest_NotFound(t *testing.T) {
 	defer svr.Close()
 	req, err := http.NewRequest(http.MethodPost, svr.URL, nil)
 	assert.Nil(t, err)
-	req.Header.Set(header.ContentType, header.JsonContentType)
+	req.Header.Set(header.ContentType, header.ContentTypeJson)
 	resp, err := DoRequest(req)
 	assert.Nil(t, err)
 	assert.Equal(t, http.StatusNotFound, resp.StatusCode)

rest/httpc/responses_test.go

@@ -18,7 +18,7 @@ func TestParse(t *testing.T) {
 	}
 	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("foo", "bar")
-		w.Header().Set(header.ContentType, header.JsonContentType)
+		w.Header().Set(header.ContentType, header.ContentTypeJson)
 		w.Write([]byte(`{"name":"kevin","value":100}`))
 	}))
 	defer svr.Close()
@@ -38,7 +38,7 @@ func TestParseHeaderError(t *testing.T) {
 	}
 	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("foo", "bar")
-		w.Header().Set(header.ContentType, header.JsonContentType)
+		w.Header().Set(header.ContentType, header.ContentTypeJson)
 	}))
 	defer svr.Close()
 	req, err := http.NewRequest(http.MethodGet, svr.URL, nil)
@@ -54,7 +54,7 @@ func TestParseNoBody(t *testing.T) {
 	}
 	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("foo", "bar")
-		w.Header().Set(header.ContentType, header.JsonContentType)
+		w.Header().Set(header.ContentType, header.ContentTypeJson)
 	}))
 	defer svr.Close()
 	req, err := http.NewRequest(http.MethodGet, svr.URL, nil)
@@ -72,7 +72,7 @@ func TestParseWithZeroValue(t *testing.T) {
 	}
 	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("foo", "0")
-		w.Header().Set(header.ContentType, header.JsonContentType)
+		w.Header().Set(header.ContentType, header.ContentTypeJson)
 		w.Write([]byte(`{"bar":0}`))
 	}))
 	defer svr.Close()
@@ -90,7 +90,7 @@ func TestParseWithNegativeContentLength(t *testing.T) {
 		Bar int `json:"bar"`
 	}
 	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set(header.ContentType, header.JsonContentType)
+		w.Header().Set(header.ContentType, header.ContentTypeJson)
 		w.Write([]byte(`{"bar":0}`))
 	}))
 	defer svr.Close()
@@ -124,7 +124,7 @@ func TestParseWithNegativeContentLength(t *testing.T) {
 func TestParseWithNegativeContentLengthNoBody(t *testing.T) {
 	var val struct{}
 	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set(header.ContentType, header.JsonContentType)
+		w.Header().Set(header.ContentType, header.ContentTypeJson)
 	}))
 	defer svr.Close()
 	req, err := http.NewRequest(http.MethodGet, svr.URL, nil)
@@ -156,7 +156,7 @@ func TestParseWithNegativeContentLengthNoBody(t *testing.T) {
 func TestParseJsonBody_BodyError(t *testing.T) {
 	var val struct{}
 	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set(header.ContentType, header.JsonContentType)
+		w.Header().Set(header.ContentType, header.ContentTypeJson)
 	}))
 	defer svr.Close()
 	req, err := http.NewRequest(http.MethodGet, svr.URL, nil)

rest/httpc/service_test.go

@@ -44,7 +44,7 @@ func TestNamedService_DoRequestPost(t *testing.T) {
 	service := NewService("foo")
 	req, err := http.NewRequest(http.MethodPost, svr.URL, nil)
 	assert.Nil(t, err)
-	req.Header.Set(header.ContentType, header.JsonContentType)
+	req.Header.Set(header.ContentType, header.ContentTypeJson)
 	resp, err := service.DoRequest(req)
 	assert.Nil(t, err)
 	assert.Equal(t, http.StatusNotFound, resp.StatusCode)

rest/httpx/requests_test.go

@@ -476,7 +476,7 @@ func TestParseJsonBody(t *testing.T) {
 
 		body := `{"name":"kevin", "age": 18}`
 		r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(body))
-		r.Header.Set(ContentType, header.JsonContentType)
+		r.Header.Set(ContentType, header.ContentTypeJson)
 
 		if assert.NoError(t, Parse(r, &v)) {
 			assert.Equal(t, "kevin", v.Name)
@@ -492,7 +492,7 @@ func TestParseJsonBody(t *testing.T) {
 
 		body := `{"name":"kevin", "ag": 18}`
 		r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(body))
-		r.Header.Set(ContentType, header.JsonContentType)
+		r.Header.Set(ContentType, header.ContentTypeJson)
 
 		assert.Error(t, Parse(r, &v))
 	})
@@ -517,7 +517,7 @@ func TestParseJsonBody(t *testing.T) {
 
 		body := `[{"name":"kevin", "age": 18}]`
 		r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(body))
-		r.Header.Set(ContentType, header.JsonContentType)
+		r.Header.Set(ContentType, header.ContentTypeJson)
 
 		assert.NoError(t, Parse(r, &v))
 		assert.Equal(t, 1, len(v))
@@ -537,7 +537,7 @@ func TestParseJsonBody(t *testing.T) {
 
 		body := `[{"name":"apple", "age": 18}]`
 		r := httptest.NewRequest(http.MethodPost, "/a?product=tree", strings.NewReader(body))
-		r.Header.Set(ContentType, header.JsonContentType)
+		r.Header.Set(ContentType, header.ContentTypeJson)
 
 		assert.NoError(t, Parse(r, &v))
 		assert.Equal(t, 1, len(v))
@@ -555,7 +555,7 @@ func TestParseJsonBody(t *testing.T) {
 		body, _ := json.Marshal(v1)
 		t.Logf("body:%s", string(body))
 		r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(string(body)))
-		r.Header.Set(ContentType, header.JsonContentType)
+		r.Header.Set(ContentType, header.ContentTypeJson)
 		var v2 v
 		err := ParseJsonBody(r, &v2)
 		if assert.NoError(t, err) {
@@ -609,7 +609,7 @@ func TestParseHeaders(t *testing.T) {
 	request.Header.Add("addrs", "addr2")
 	request.Header.Add("X-Forwarded-For", "10.0.10.11")
 	request.Header.Add("x-real-ip", "10.0.11.10")
-	request.Header.Add("Accept", header.JsonContentType)
+	request.Header.Add("Accept", header.ContentTypeJson)
 	err = ParseHeaders(request, &v)
 	if err != nil {
 		t.Fatal(err)
@@ -619,7 +619,7 @@ func TestParseHeaders(t *testing.T) {
 	assert.Equal(t, []string{"addr1", "addr2"}, v.Addrs)
 	assert.Equal(t, "10.0.10.11", v.XForwardedFor)
 	assert.Equal(t, "10.0.11.10", v.XRealIP)
-	assert.Equal(t, header.JsonContentType, v.Accept)
+	assert.Equal(t, header.ContentTypeJson, v.Accept)
 }
 
 func TestParseHeaders_Error(t *testing.T) {
@@ -711,7 +711,7 @@ func TestParseWithFloatPtr(t *testing.T) {
 		}
 		body := `{"weightFloat32": 3.2}`
 		r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(body))
-		r.Header.Set(ContentType, header.JsonContentType)
+		r.Header.Set(ContentType, header.ContentTypeJson)
 
 		if assert.NoError(t, Parse(r, &v)) {
 			assert.Equal(t, float32(3.2), *v.WeightFloat32)

rest/httpx/responses.go

@@ -179,7 +179,7 @@ func doWriteJson(w http.ResponseWriter, code int, v any) error {
 		return fmt.Errorf("marshal json failed, error: %w", err)
 	}
 
-	w.Header().Set(ContentType, header.JsonContentType)
+	w.Header().Set(ContentType, header.ContentTypeJson)
 	w.WriteHeader(code)
 
 	if n, err := w.Write(bs); err != nil {

rest/httpx/vars.go

@@ -10,7 +10,7 @@ const (
 	// ContentType means Content-Type.
 	ContentType = header.ContentType
 	// JsonContentType means application/json.
-	JsonContentType = header.JsonContentType
+	JsonContentType = header.ContentTypeJson
 	// KeyField means key.
 	KeyField = "key"
 	// SecretField means secret.

rest/internal/header/headers.go

@@ -3,8 +3,18 @@ package header
 const (
 	// ApplicationJson stands for application/json.
 	ApplicationJson = "application/json"
+	// CacheControl is the header key for Cache-Control.
+	CacheControl = "Cache-Control"
+	// CacheControlNoCache is the value for Cache-Control: no-cache.
+	CacheControlNoCache = "no-cache"
+	// Connection is the header key for Connection.
+	Connection = "Connection"
+	// ConnectionKeepAlive is the value for Connection: keep-alive.
+	ConnectionKeepAlive = "keep-alive"
 	// ContentType is the header key for Content-Type.
 	ContentType = "Content-Type"
-	// JsonContentType is the content type for JSON.
+	// ContentTypeJson is the content type for JSON.
-	JsonContentType = "application/json; charset=utf-8"
+	ContentTypeJson = "application/json; charset=utf-8"
+	// ContentTypeEventStream is the content type for event stream.
+	ContentTypeEventStream = "text/event-stream"
 )

rest/router/patrouter_test.go

@@ -628,7 +628,7 @@ func TestParseWrappedRequest(t *testing.T) {
 func TestParseWrappedGetRequestWithJsonHeader(t *testing.T) {
 	r, err := http.NewRequest(http.MethodGet, "http://hello.com/kevin/2017", bytes.NewReader(nil))
 	assert.Nil(t, err)
-	r.Header.Set(httpx.ContentType, header.JsonContentType)
+	r.Header.Set(httpx.ContentType, header.ContentTypeJson)
 
 	type (
 		Request struct {
@@ -661,7 +661,7 @@ func TestParseWrappedGetRequestWithJsonHeader(t *testing.T) {
 func TestParseWrappedHeadRequestWithJsonHeader(t *testing.T) {
 	r, err := http.NewRequest(http.MethodHead, "http://hello.com/kevin/2017", bytes.NewReader(nil))
 	assert.Nil(t, err)
-	r.Header.Set(httpx.ContentType, header.JsonContentType)
+	r.Header.Set(httpx.ContentType, header.ContentTypeJson)
 
 	type (
 		Request struct {
@@ -758,7 +758,7 @@ func TestParseWithAllUtf8(t *testing.T) {
 	r, err := http.NewRequest(http.MethodPost, "http://hello.com/kevin/2017?nickname=whatever&zipcode=200000",
 		bytes.NewBufferString(`{"location": "shanghai", "time": 20170912}`))
 	assert.Nil(t, err)
-	r.Header.Set(httpx.ContentType, header.JsonContentType)
+	r.Header.Set(httpx.ContentType, header.ContentTypeJson)
 
 	router := NewRouter()
 	err = router.Handle(http.MethodPost, "/:name/:year", http.HandlerFunc(
@@ -948,7 +948,7 @@ func TestParseWithMissingAllPaths(t *testing.T) {
 func TestParseGetWithContentLengthHeader(t *testing.T) {
 	r, err := http.NewRequest(http.MethodGet, "http://hello.com/kevin/2017?nickname=whatever&zipcode=200000", nil)
 	assert.Nil(t, err)
-	r.Header.Set(httpx.ContentType, header.JsonContentType)
+	r.Header.Set(httpx.ContentType, header.ContentTypeJson)
 	r.Header.Set(contentLength, "1024")
 
 	router := NewRouter()
@@ -976,7 +976,7 @@ func TestParseJsonPostWithTypeMismatch(t *testing.T) {
 	r, err := http.NewRequest(http.MethodPost, "http://hello.com/kevin/2017?nickname=whatever&zipcode=200000",
 		bytes.NewBufferString(`{"time": "20170912"}`))
 	assert.Nil(t, err)
-	r.Header.Set(httpx.ContentType, header.JsonContentType)
+	r.Header.Set(httpx.ContentType, header.ContentTypeJson)
 
 	router := NewRouter()
 	err = router.Handle(http.MethodPost, "/:name/:year", http.HandlerFunc(
@@ -1002,7 +1002,7 @@ func TestParseJsonPostWithInt2String(t *testing.T) {
 	r, err := http.NewRequest(http.MethodPost, "http://hello.com/kevin/2017",
 		bytes.NewBufferString(`{"time": 20170912}`))
 	assert.Nil(t, err)
-	r.Header.Set(httpx.ContentType, header.JsonContentType)
+	r.Header.Set(httpx.ContentType, header.ContentTypeJson)
 
 	router := NewRouter()
 	err = router.Handle(http.MethodPost, "/:name/:year", http.HandlerFunc(

rest/server.go

@@ -63,6 +63,11 @@ func NewServer(c RestConf, opts ...RunOption) (*Server, error) {
 	return server, nil
 }
 
+// AddRoute adds given route into the Server.
+func (s *Server) AddRoute(r Route, opts ...RouteOption) {
+	s.AddRoutes([]Route{r}, opts...)
+}
+
 // AddRoutes add given routes into the Server.
 func (s *Server) AddRoutes(rs []Route, opts ...RouteOption) {
 	r := featuredRoutes{
@@ -74,11 +79,6 @@ func (s *Server) AddRoutes(rs []Route, opts ...RouteOption) {
 	s.ngin.addRoutes(r)
 }
 
-// AddRoute adds given route into the Server.
-func (s *Server) AddRoute(r Route, opts ...RouteOption) {
-	s.AddRoutes([]Route{r}, opts...)
-}
-
 // PrintRoutes prints the added routes to stdout.
 func (s *Server) PrintRoutes() {
 	s.ngin.print()
@@ -279,6 +279,14 @@ func WithSignature(signature SignatureConf) RouteOption {
 	}
 }
 
+// WithSSE returns a RouteOption to enable server-sent events.
+func WithSSE() RouteOption {
+	return func(r *featuredRoutes) {
+		r.sse = true
+		r.timeout = 0
+	}
+}
+
 // WithTimeout returns a RouteOption to set timeout with given value.
 func WithTimeout(timeout time.Duration) RouteOption {
 	return func(r *featuredRoutes) {

rest/server_test.go

@@ -20,6 +20,7 @@ import (
 	"github.com/zeromicro/go-zero/rest/chain"
 	"github.com/zeromicro/go-zero/rest/httpx"
 	"github.com/zeromicro/go-zero/rest/internal/cors"
+	"github.com/zeromicro/go-zero/rest/internal/header"
 	"github.com/zeromicro/go-zero/rest/router"
 )
 
@@ -754,6 +755,40 @@ Port: 54321
 	}
 }
 
+func TestServerEventStream(t *testing.T) {
+	server := MustNewServer(RestConf{})
+	server.AddRoutes([]Route{
+		{
+			Method: http.MethodGet,
+			Path:   "/foo",
+			Handler: func(w http.ResponseWriter, r *http.Request) {
+				w.Write([]byte("foo"))
+			},
+		},
+		{
+			Method: http.MethodGet,
+			Path:   "/bar",
+			Handler: func(w http.ResponseWriter, r *http.Request) {
+				w.Write([]byte("bar"))
+			},
+		},
+	}, WithSSE())
+
+	check := func(val string) {
+		req, err := http.NewRequest(http.MethodGet, fmt.Sprintf("/%s", val), http.NoBody)
+		assert.Nil(t, err)
+		rr := httptest.NewRecorder()
+		serve(server, rr, req)
+		assert.Equal(t, http.StatusOK, rr.Code)
+		assert.Equal(t, header.ContentTypeEventStream, rr.Header().Get(header.ContentType))
+		assert.Equal(t, header.CacheControlNoCache, rr.Header().Get(header.CacheControl))
+		assert.Equal(t, header.ConnectionKeepAlive, rr.Header().Get(header.Connection))
+		assert.Equal(t, val, rr.Body.String())
+	}
+	check("foo")
+	check("bar")
+}
+
 //go:embed testdata
 var content embed.FS
 
@@ -770,7 +805,7 @@ func TestServerEmbedFileSystem(t *testing.T) {
 }
 
 // serve is for test purpose, allow developer to do a unit test with
-// all defined router without starting an HTTP Server.
+// all defined routes without starting an HTTP Server.
 //
 // For example:
 //

rest/types.go

@@ -35,6 +35,7 @@ type (
 		priority  bool
 		jwt       jwtSetting
 		signature signatureSetting
+		sse       bool
 		routes    []Route
 		maxBytes  int64
 	}