snapshot of https://github.com/nats-io/nats-server.git (main, 2026-09-15; blobs > 131072B omitted)

server/subject_fuzz_test.go

@@ -0,0 +1,71 @@
+// Copyright 2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package server
+
+import "testing"
+
+// FuzzSubjectsCollide performs fuzz testing on the NATS subject collision detection logic.
+// It verifies the behavior of the SubjectsCollide function which determines if two NATS
+// subjects/subscriptions could potentially overlap in the NATS pub-sub system.
+func FuzzSubjectsCollide(f *testing.F) {
+	corpuses := []struct {
+		s1 string
+		s2 string
+	}{
+		// SubjectsCollide true
+		{s1: "", s2: ""},
+		{s1: "a", s2: "a"},
+		{s1: "a.b.c", s2: "a.b.c"},
+		{s1: "$JS.b.c", s2: "$JS.b.c"},
+		{s1: "a.b.c", s2: "a.*.c"},
+		{s1: "a.b.*", s2: "a.*.c"},
+		{s1: "aaa.bbb.ccc", s2: "aaa.bbb.ccc"},
+		{s1: "aaa.*.ccc", s2: "*.bbb.ccc"},
+		{s1: "*", s2: "*"},
+		{s1: "**", s2: "*"},
+		{s1: "", s2: ">"},
+		{s1: ">", s2: ">"},
+		{s1: ">>", s2: ">"},
+		{s1: "a", s2: ">"},
+		{s1: "a.b.c", s2: ">"},
+		{s1: "a.b.c.>", s2: "a.b.>"},
+		{s1: "a.b.c.d.*", s2: "a.b.c.*.e"},
+		{s1: "a.*.*.d.>", s2: "a.bbb.ccc.*.e"},
+
+		// SubjectsCollide false
+		{s1: "a", s2: ""},
+		{s1: "a.b", s2: "b.a"},
+		{s1: "a.bbbbb.*.d", s2: "a.b.>"},
+		{s1: "a.b", s2: "a.b.c"},
+		{s1: "a.b.c", s2: "a.b"},
+		{s1: "a.b", s2: ""},
+		{s1: "a.*.*.d.e.>", s2: "a.bbb.ccc.*.e"},
+	}
+
+	for _, crp := range corpuses {
+		f.Add(crp.s1, crp.s2)
+	}
+
+	f.Fuzz(func(t *testing.T, s1, s2 string) {
+		if !IsValidSubject(s1) {
+			return
+		}
+
+		if !IsValidSubject(s2) {
+			return
+		}
+
+		SubjectsCollide(s1, s2)
+	})
+}