Fix: Multiple Matchers Consuming Request Body Causing Stub Handler Failure

httpstub.go

@@ -247,7 +247,7 @@ func (rt *Router) Close() {
 // Match create request matcher with matchFunc (func(r *http.Request) bool).
 func (rt *Router) Match(fn func(r *http.Request) bool) *matcher {
 	m := &matcher{
-		matchFuncs: []matchFunc{fn},
+		matchFuncs: []matchFunc{withCloneReq(fn)},
 		router:     rt,
 	}
 	rt.mu.Lock()
@@ -260,7 +260,7 @@ func (rt *Router) Match(fn func(r *http.Request) bool) *matcher {
 func (m *matcher) Match(fn func(r *http.Request) bool) *matcher {
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	m.matchFuncs = append(m.matchFuncs, fn)
+	m.matchFuncs = append(m.matchFuncs, withCloneReq(fn))
 	return m
 }
 
@@ -650,3 +650,10 @@ func matchOne[T any](m map[string]*T, pattern string) (string, *T) {
 	}
 	return "", nil
 }
+
+func withCloneReq(fn matchFunc) matchFunc {
+	return func(r *http.Request) bool {
+		r2 := cloneReq(r)
+		return fn(r2)
+	}
+}

httpstub_test.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"strings"
 	"testing"
 
 	"github.com/golang/mock/gomock"
@@ -107,6 +108,95 @@ func TestMatcherMatch(t *testing.T) {
 	}
 }
 
+func TestMatcherMatchConsumingBody(t *testing.T) {
+	t.Run("only Match", func(t *testing.T) {
+		rt := NewRouter(t)
+		rt.Match(func(r *http.Request) bool {
+			b, err := io.ReadAll(r.Body)
+			if err != nil {
+				return false
+			}
+			return strings.Contains(string(b), "add")
+		}).Response(http.StatusAccepted, nil)
+		rt.Match(func(r *http.Request) bool {
+			b, err := io.ReadAll(r.Body)
+			if err != nil {
+				return false
+			}
+			return strings.Contains(string(b), "subtract")
+		}).Response(http.StatusAccepted, nil)
+		ts := rt.Server()
+		t.Cleanup(func() {
+			ts.Close()
+		})
+		tc := ts.Client()
+		res, err := tc.Post("https://example.com/jrpc", "application/json", strings.NewReader(`{"jsonrpc":"2.0", "method": "subtract", "params": {"a": 10, "b": 3}, "id": 123}`))
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Cleanup(func() {
+			res.Body.Close()
+		})
+
+		requests := rt.Requests()
+		if len(requests) != 1 {
+			t.Errorf("got %v\nwant %v", len(requests), 1)
+		}
+		b, err := io.ReadAll(requests[0].Body)
+		if err != nil {
+			t.Fatal(err)
+		}
+		got := string(b)
+		want := `{"jsonrpc":"2.0", "method": "subtract", "params": {"a": 10, "b": 3}, "id": 123}`
+		if got != want {
+			t.Errorf("got %v\nwant %v", got, want)
+		}
+	})
+	t.Run("Path and Match", func(t *testing.T) {
+		rt := NewRouter(t)
+		rt.Path("/jrpc").Match(func(r *http.Request) bool {
+			b, err := io.ReadAll(r.Body)
+			if err != nil {
+				return false
+			}
+			return strings.Contains(string(b), "add")
+		}).Response(http.StatusAccepted, nil)
+		rt.Path("/jrpc").Match(func(r *http.Request) bool {
+			b, err := io.ReadAll(r.Body)
+			if err != nil {
+				return false
+			}
+			return strings.Contains(string(b), "subtract")
+		}).Response(http.StatusAccepted, nil)
+		ts := rt.Server()
+		t.Cleanup(func() {
+			ts.Close()
+		})
+		tc := ts.Client()
+		res, err := tc.Post("https://example.com/jrpc", "application/json", strings.NewReader(`{"jsonrpc":"2.0", "method": "subtract", "params": {"a": 10, "b": 3}, "id": 123}`))
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Cleanup(func() {
+			res.Body.Close()
+		})
+
+		requests := rt.Requests()
+		if len(requests) != 1 {
+			t.Errorf("got %v\nwant %v", len(requests), 1)
+		}
+		b, err := io.ReadAll(requests[0].Body)
+		if err != nil {
+			t.Fatal(err)
+		}
+		got := string(b)
+		want := `{"jsonrpc":"2.0", "method": "subtract", "params": {"a": 10, "b": 3}, "id": 123}`
+		if got != want {
+			t.Errorf("got %v\nwant %v", got, want)
+		}
+	})
+}
+
 func TestMatcherMethod(t *testing.T) {
 	rt := NewRouter(t)
 	rt.Path("/api/v1/users/1").Method(http.MethodGet).ResponseString(http.StatusAccepted, `{"message":"accepted"}`)