Add go fuzzer in preparation for testing. Also gofmt a few files that needed it.

pkg/util/fuzz_test.go

@@ -0,0 +1,229 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 util
+
+import (
+	"testing"
+)
+
+func TestFuzz_basic(t *testing.T) {
+	obj := &struct {
+		I    int
+		I8   int8
+		I16  int16
+		I32  int32
+		I64  int64
+		U    uint
+		U8   uint8
+		U16  uint16
+		U32  uint32
+		U64  uint64
+		Uptr uintptr
+		S    string
+		B    bool
+	}{}
+
+	failed := map[string]int{}
+	for i := 0; i < 10; i++ {
+		NewFuzzer().Fuzz(obj)
+
+		if n, v := "i", obj.I; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "i8", obj.I8; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "i16", obj.I16; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "i32", obj.I32; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "i64", obj.I64; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "u", obj.U; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "u8", obj.U8; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "u16", obj.U16; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "u32", obj.U32; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "u64", obj.U64; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "uptr", obj.Uptr; v == 0 {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "s", obj.S; v == "" {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "b", obj.B; v == false {
+			failed[n] = failed[n] + 1
+		}
+	}
+	checkFailed(t, failed)
+}
+
+func checkFailed(t *testing.T, failed map[string]int) {
+	for k, v := range failed {
+		if v > 8 {
+			t.Errorf("%v seems to not be getting set, was zero value %v times", k, v)
+		}
+	}
+}
+
+func TestFuzz_structptr(t *testing.T) {
+	obj := &struct {
+		A *struct {
+			S string
+		}
+	}{}
+
+	failed := map[string]int{}
+	for i := 0; i < 10; i++ {
+		NewFuzzer().Fuzz(obj)
+
+		if n, v := "a", obj.A; v == nil {
+			failed[n] = failed[n] + 1
+		}
+		if n, v := "as", obj.A; v == nil || v.S == "" {
+			failed[n] = failed[n] + 1
+		}
+	}
+	checkFailed(t, failed)
+}
+
+// Try fuzzing up to 20 times. Fail if check() never passes.
+func tryFuzz(t *testing.T, obj interface{}, check func() (stage int, passed bool)) {
+	maxStage := 0
+	for i := 0; i < 20; i++ {
+		NewFuzzer().Fuzz(obj)
+		stage, passed := check()
+		if stage > maxStage {
+			maxStage = stage
+		}
+		if passed {
+			return
+		}
+	}
+	t.Errorf("Only ever got to stage %v", maxStage)
+}
+
+func TestFuzz_structmap(t *testing.T) {
+	obj := &struct {
+		A map[struct {
+			S string
+		}]struct {
+			S2 string
+		}
+		B map[string]string
+	}{}
+
+	tryFuzz(t, obj, func() (int, bool) {
+		if obj.A == nil {
+			return 1, false
+		}
+		if len(obj.A) == 0 {
+			return 2, false
+		}
+		for k, v := range obj.A {
+			if k.S == "" {
+				return 3, false
+			}
+			if v.S2 == "" {
+				return 4, false
+			}
+		}
+
+		if obj.B == nil {
+			return 5, false
+		}
+		if len(obj.B) == 0 {
+			return 6, false
+		}
+		for k, v := range obj.B {
+			if k == "" {
+				return 7, false
+			}
+			if v == "" {
+				return 8, false
+			}
+		}
+		return 9, true
+	})
+}
+
+func TestFuzz_structslice(t *testing.T) {
+	obj := &struct {
+		A []struct {
+			S string
+		}
+		B []string
+	}{}
+
+	tryFuzz(t, obj, func() (int, bool) {
+		if obj.A == nil {
+			return 1, false
+		}
+		if len(obj.A) == 0 {
+			return 2, false
+		}
+		for _, v := range obj.A {
+			if v.S == "" {
+				return 3, false
+			}
+		}
+
+		if obj.B == nil {
+			return 4, false
+		}
+		if len(obj.B) == 0 {
+			return 5, false
+		}
+		for _, v := range obj.B {
+			if v == "" {
+				return 6, false
+			}
+		}
+		return 7, true
+	})
+}
+
+func TestFuzz_custom(t *testing.T) {
+	obj := &struct {
+		A string
+		B *string
+	}{}
+
+	testPhrase := "gotcalled"
+	NewFuzzer(func(s *string) { *s = testPhrase }).Fuzz(obj)
+	if obj.A != testPhrase {
+		t.Errorf("A not set")
+	}
+	if obj.B == nil {
+		t.Fatalf("B is nil")
+	}
+	if *obj.B != testPhrase {
+		t.Errorf("B not set")
+	}
+}