Learnt how to do fuzzing, create a new module called learn fuzzing and gone through the flow of fuzzing. Need furthur study

Author: anarchymonkey

learn_fuzzing/go.mod

@@ -0,0 +1,3 @@
+module batsy.com/main
+
+go 1.20

learn_fuzzing/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"unicode/utf8"
+)
+
+func ReverseString(str string) (string, error) {
+
+	if !utf8.ValidString(str) {
+		return "", errors.New("The string is not valid UTF-8 %s" + str)
+	}
+	b := []rune(str)
+
+	for i, j := 0, len(b)-1; i < len(b)/2; i, j = i+1, j-1 {
+		b[i], b[j] = b[j], b[i]
+	}
+
+	return string(b), nil
+}
+
+func main() {
+
+	const NEW_STRING = "Aniket"
+
+	reversedString, error := ReverseString(NEW_STRING)
+
+	if error != nil {
+		log.Fatal("Some error occured")
+	}
+
+	doubleReversedString, error := ReverseString(reversedString)
+
+	if error != nil {
+		log.Fatal("Some error occured")
+	}
+
+	fmt.Println("The reversed string is", reversedString)
+	fmt.Println("The double reversed string is", doubleReversedString)
+}

learn_fuzzing/main_test.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+	"unicode/utf8"
+)
+
+// This is a normal test case
+func TestReverseString(t *testing.T) {
+
+	testCases := []struct {
+		in, want string
+	}{
+		{"Aniket", "tekinA"},
+		{"hie", "eih"},
+		{"Hue", "euH"},
+	}
+
+	for _, tc := range testCases {
+		reversedString, error := ReverseString(tc.in)
+
+		if error != nil {
+			t.Errorf("Something Went Wrong")
+		}
+
+		if reversedString != tc.want {
+			t.Errorf("The input was %s, the reversed string which did not match was %s, which was expected to be %s", tc.in, reversedString, tc.want)
+		}
+	}
+}
+
+func FuzzReverseString(f *testing.F) {
+
+	// add a fuzz test case
+
+	testcases := []string{
+		"Aniket",
+		"Namaste",
+		"Jhingalala",
+		// "",
+	}
+
+	for _, tc := range testcases {
+		// This adds a seed corpus, in simple terms I think it takes a sample input which it can make permutations of
+		f.Add(tc)
+	}
+
+	// This represents the actual testing scenario where we would run the test
+	f.Fuzz(func(t *testing.T, originalString string) {
+		reversedString, error := ReverseString(originalString)
+
+		if error != nil {
+			fmt.Println(error)
+			return
+		}
+		doubleReverse, error := ReverseString(reversedString)
+
+		if error != nil {
+			t.Errorf("Some error occured in double Reverse string")
+			return
+		}
+
+		if originalString != doubleReverse {
+			t.Errorf("The original string reference did not match")
+		}
+
+		if utf8.ValidString(originalString) && !utf8.ValidString(reversedString) {
+			t.Errorf("Reverse produced invalid UTF-8 string %q", reversedString)
+		}
+	})
+}

learn_fuzzing/testdata/fuzz/FuzzReverseString/1e9372cf5026ba11

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+go test fuzz v1
+string("̴")

learn_fuzzing/testdata/fuzz/FuzzReverseString/4316c263ab833860

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+go test fuzz v1
+string("\xd7")

learn_fuzzing/testdata/fuzz/FuzzReverseString/514c8f04371e75e7

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+go test fuzz v1
+string("0\xd7")