Add Go fuzz tests for OSS-Fuzz integration

fuzz_test.go

@@ -0,0 +1,106 @@
+//go:build go1.18
+// +build go1.18
+
+// Copyright 2026 Google LLC
+//
+// 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 testify_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func FuzzAssertEqual(f *testing.F) {
+	f.Add("hello", "hello")
+	f.Add("", "")
+	f.Add("hello", "world")
+	f.Fuzz(func(t *testing.T, expected, actual string) {
+		if len(expected) > 10000 || len(actual) > 10000 {
+			return
+		}
+		func() {
+			defer func() { recover() }()
+			mockT := new(testing.T)
+			assert.Equal(mockT, expected, actual)
+			assert.NotEqual(mockT, expected, "different-"+expected)
+			assert.Contains(mockT, expected+actual, expected)
+		}()
+	})
+}
+
+func FuzzAssertJSON(f *testing.F) {
+	f.Add(`{"a":1}`, `{"a":1}`)
+	f.Add(`{"a":1}`, `{"a":2}`)
+	f.Add(`[1,2,3]`, `[1,2,3]`)
+	f.Add(`null`, `null`)
+	f.Add(`"hello"`, `"hello"`)
+	f.Fuzz(func(t *testing.T, expectedJSON, actualJSON string) {
+		if len(expectedJSON) > 1<<16 || len(actualJSON) > 1<<16 {
+			return
+		}
+		func() {
+			defer func() { recover() }()
+			mockT := new(testing.T)
+			assert.JSONEq(mockT, expectedJSON, actualJSON)
+		}()
+	})
+}
+
+func FuzzAssertYAML(f *testing.F) {
+	f.Add("key: value", "key: value")
+	f.Add("list:\n  - a\n  - b", "list:\n  - a\n  - b")
+	f.Add("", "")
+	f.Fuzz(func(t *testing.T, expectedYAML, actualYAML string) {
+		if len(expectedYAML) > 1<<16 || len(actualYAML) > 1<<16 {
+			return
+		}
+		func() {
+			defer func() { recover() }()
+			mockT := new(testing.T)
+			assert.YAMLEq(mockT, expectedYAML, actualYAML)
+		}()
+	})
+}
+
+func FuzzRequireInt(f *testing.F) {
+	f.Add(42, 42)
+	f.Add(-1, 0)
+	f.Fuzz(func(t *testing.T, val, compare int) {
+		func() {
+			defer func() { recover() }()
+			mockT := new(testing.T)
+			require.NotNil(mockT, &val)
+			require.GreaterOrEqual(mockT, val, compare-1)
+			require.LessOrEqual(mockT, val, compare+100)
+		}()
+	})
+}
+
+func FuzzElementsMatch(f *testing.F) {
+	f.Add("a", "b", "c")
+	f.Add("", "", "")
+	f.Fuzz(func(t *testing.T, a, b, c string) {
+		if len(a) > 1000 || len(b) > 1000 || len(c) > 1000 {
+			return
+		}
+		func() {
+			defer func() { recover() }()
+			mockT := new(testing.T)
+			assert.ElementsMatch(mockT, []string{a, b, c}, []string{c, b, a})
+		}()
+	})
+}