mutator_test.go

     1  // Copyright 2021 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package fuzz
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"os"
    11  	"strconv"
    12  	"testing"
    13  )
    14  
    15  func BenchmarkMutatorBytes(b *testing.B) {
    16  	origEnv := os.Getenv("GODEBUG")
    17  	defer func() { os.Setenv("GODEBUG", origEnv) }()
    18  	os.Setenv("GODEBUG", fmt.Sprintf("%s,fuzzseed=123", origEnv))
    19  	m := newMutator()
    20  
    21  	for _, size := range []int{
    22  		1,
    23  		10,
    24  		100,
    25  		1000,
    26  		10000,
    27  		100000,
    28  	} {
    29  		b.Run(strconv.Itoa(size), func(b *testing.B) {
    30  			buf := make([]byte, size)
    31  			b.ResetTimer()
    32  
    33  			for i := 0; i < b.N; i++ {
    34  				// resize buffer to the correct shape and reset the PCG
    35  				buf = buf[0:size]
    36  				m.r = newPcgRand()
    37  				m.mutate([]any{buf}, workerSharedMemSize)
    38  			}
    39  		})
    40  	}
    41  }
    42  
    43  func BenchmarkMutatorString(b *testing.B) {
    44  	origEnv := os.Getenv("GODEBUG")
    45  	defer func() { os.Setenv("GODEBUG", origEnv) }()
    46  	os.Setenv("GODEBUG", fmt.Sprintf("%s,fuzzseed=123", origEnv))
    47  	m := newMutator()
    48  
    49  	for _, size := range []int{
    50  		1,
    51  		10,
    52  		100,
    53  		1000,
    54  		10000,
    55  		100000,
    56  	} {
    57  		b.Run(strconv.Itoa(size), func(b *testing.B) {
    58  			buf := make([]byte, size)
    59  			b.ResetTimer()
    60  
    61  			for i := 0; i < b.N; i++ {
    62  				// resize buffer to the correct shape and reset the PCG
    63  				buf = buf[0:size]
    64  				m.r = newPcgRand()
    65  				m.mutate([]any{string(buf)}, workerSharedMemSize)
    66  			}
    67  		})
    68  	}
    69  }
    70  
    71  func BenchmarkMutatorAllBasicTypes(b *testing.B) {
    72  	origEnv := os.Getenv("GODEBUG")
    73  	defer func() { os.Setenv("GODEBUG", origEnv) }()
    74  	os.Setenv("GODEBUG", fmt.Sprintf("%s,fuzzseed=123", origEnv))
    75  	m := newMutator()
    76  
    77  	types := []any{
    78  		[]byte(""),
    79  		string(""),
    80  		false,
    81  		float32(0),
    82  		float64(0),
    83  		int(0),
    84  		int8(0),
    85  		int16(0),
    86  		int32(0),
    87  		int64(0),
    88  		uint8(0),
    89  		uint16(0),
    90  		uint32(0),
    91  		uint64(0),
    92  	}
    93  
    94  	for _, t := range types {
    95  		b.Run(fmt.Sprintf("%T", t), func(b *testing.B) {
    96  			for i := 0; i < b.N; i++ {
    97  				m.r = newPcgRand()
    98  				m.mutate([]any{t}, workerSharedMemSize)
    99  			}
   100  		})
   101  	}
   102  }
   103  
   104  func TestStringImmutability(t *testing.T) {
   105  	v := []any{"hello"}
   106  	m := newMutator()
   107  	m.mutate(v, 1024)
   108  	original := v[0].(string)
   109  	originalCopy := make([]byte, len(original))
   110  	copy(originalCopy, []byte(original))
   111  	for i := 0; i < 25; i++ {
   112  		m.mutate(v, 1024)
   113  	}
   114  	if !bytes.Equal([]byte(original), originalCopy) {
   115  		t.Fatalf("string was mutated: got %x, want %x", []byte(original), originalCopy)
   116  	}
   117  }
   118
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