fix(middlewares): correctly bypass middlewares with response rules

internal/net/gphttp/middleware/bypass.go

@@ -30,8 +30,8 @@ func (c *checkBypass) before(w http.ResponseWriter, r *http.Request) (proceedNex
 	return c.modReq.before(w, r)
 }
 
-func (c *checkBypass) modifyResponse(w http.ResponseWriter, resp *http.Response) error {
-	if c.modRes == nil || c.bypass.ShouldBypass(w, resp.Request) {
+func (c *checkBypass) modifyResponse(resp *http.Response) error {
+	if c.modRes == nil || c.bypass.ShouldBypass(rules.ResponseAsRW(resp), resp.Request) {
 		return nil
 	}
 	return c.modRes.modifyResponse(resp)

internal/net/gphttp/middleware/bypass_test.go

@@ -138,6 +138,82 @@ func TestReverseProxyBypass(t *testing.T) {
 	}
 }
 
+func TestBypassResponse(t *testing.T) {
+	t.Run("req_rules", func(t *testing.T) {
+		mr, err := ModifyResponse.New(map[string]any{
+			"bypass": []string{"path glob(/test/*) | path /api"},
+			"set_headers": map[string]string{
+				"Test-Header": "test-value",
+			},
+		})
+		expect.NoError(t, err)
+
+		tests := []struct {
+			name         string
+			path         string
+			expectBypass bool
+		}{
+			{"bypass", "/test/123", true},
+			{"bypass2", "/test/123/456", true},
+			{"bypass3", "/api", true},
+		}
+
+		for _, test := range tests {
+			t.Run(test.name, func(t *testing.T) {
+				req := httptest.NewRequest("GET", "http://example.com"+test.path, nil)
+				resp := &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(strings.NewReader("test")),
+					Request:    req,
+					Header:     make(http.Header),
+				}
+				mErr := mr.ModifyResponse(resp)
+				expect.NoError(t, mErr)
+				if test.expectBypass {
+					expect.Equal(t, resp.Header.Get("Test-Header"), "")
+				} else {
+					expect.Equal(t, resp.Header.Get("Test-Header"), "test-value")
+				}
+			})
+		}
+	})
+	t.Run("res_rules", func(t *testing.T) {
+		mr, err := ModifyResponse.New(map[string]any{
+			"bypass": []string{"status 200"},
+			"set_headers": map[string]string{
+				"Test-Header": "test-value",
+			},
+		})
+		expect.NoError(t, err)
+
+		tests := []struct {
+			name         string
+			statusCode   int
+			expectBypass bool
+		}{
+			{"bypass", 200, true},
+			{"no_bypass", 201, false},
+		}
+
+		for _, test := range tests {
+			t.Run(test.name, func(t *testing.T) {
+				resp := &http.Response{
+					StatusCode: test.statusCode,
+					Body:       io.NopCloser(strings.NewReader("test")),
+					Header:     make(http.Header),
+				}
+				mErr := mr.ModifyResponse(resp)
+				expect.NoError(t, mErr)
+				if test.expectBypass {
+					expect.Equal(t, resp.Header.Get("Test-Header"), "")
+				} else {
+					expect.Equal(t, resp.Header.Get("Test-Header"), "test-value")
+				}
+			})
+		}
+	})
+}
+
 func TestEntrypointBypassRoute(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte("test"))

internal/route/rules/response_modifier.go

@@ -4,10 +4,12 @@ import (
 	"bufio"
 	"bytes"
 	"errors"
+	"io"
 	"net"
 	"net/http"
 	"strconv"
 
+	"github.com/rs/zerolog/log"
 	gperr "github.com/yusing/goutils/errs"
 	"github.com/yusing/goutils/synk"
 )
@@ -43,6 +45,29 @@ func unwrapResponseModifier(w http.ResponseWriter) *ResponseModifier {
 	}
 }
 
+type responseAsRW struct {
+	resp *http.Response
+}
+
+func (r responseAsRW) WriteHeader(code int) {
+	log.Error().Msg("write header after response has been created")
+}
+
+func (r responseAsRW) Write(b []byte) (int, error) {
+	return 0, io.ErrClosedPipe
+}
+
+func (r responseAsRW) Header() http.Header {
+	return r.resp.Header
+}
+
+func ResponseAsRW(resp *http.Response) *ResponseModifier {
+	return &ResponseModifier{
+		statusCode: resp.StatusCode,
+		w:          responseAsRW{resp},
+	}
+}
+
 // GetInitResponseModifier returns the response modifier for the given response writer.
 // If the response writer is already wrapped, it will return the wrapped response modifier.
 // Otherwise, it will return a new response modifier.