main: set output directory properly (#33)

fuzzer/fuzzer.go

@@ -42,9 +42,21 @@ import (
 
 var (
 	outputDir   = "out"
+	EnvKey      = "FUZZYDIR"
 	shouldTrace = false
 )
 
+// SetFuzzyVMDir sets the output directory for FuzzyVM
+// If the environment variable FUZZYDIR is set, the output directory
+// will be set to that, otherwise it will be set to a temp dir (for unit tests)
+func SetFuzzyVMDir() {
+	if dir, ok := os.LookupEnv(EnvKey); ok {
+		outputDir = dir
+	} else {
+		outputDir = os.TempDir()
+	}
+}
+
 // Fuzz is the entry point for go-fuzz
 func Fuzz(data []byte) int {
 	// Too little data destroys our performance and makes it hard for the generator

fuzzer/fuzzer_test.go

@@ -28,7 +28,7 @@ import (
 )
 
 func init() {
-	outputDir = os.TempDir()
+	SetFuzzyVMDir()
 	var directories []string
 	for i := 0; i < 256; i++ {
 		directories = append(directories, fmt.Sprintf("%v/%v", outputDir, common.Bytes2Hex([]byte{byte(i)})))

main.go

@@ -24,6 +24,7 @@ import (
 	"io/ioutil"
 	"os"
 	"os/exec"
+	"path/filepath"
 
 	"github.com/urfave/cli/v2"
 
@@ -141,6 +142,14 @@ func startGenerator(genThreads int) *exec.Cmd {
 	cmd := exec.Command(cmdName, "test", "--fuzz", target, "--parallel", fmt.Sprint(genThreads), dir)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
+	// Set the output directory
+	path, err := os.Getwd()
+	if err != nil {
+		panic(err)
+	}
+	directory := filepath.Join(path, outputRootDir)
+	env := append(os.Environ(), fmt.Sprintf("%v=%v", fuzzer.EnvKey, directory))
+	cmd.Env = env
 	if err := cmd.Start(); err != nil {
 		panic(err)
 	}