Problem: make check shows errors

Solution: tweak linters configurations and
fix code

Fixes #13.

.golangci.yml

@@ -33,5 +33,8 @@ linters:
 issues:
   exclude-use-default: false
   exclude:
-    # gas: Duplicates errcheck, but with more false positives like strings.Builder.WriteString
+    # gosec: Duplicates errcheck, but with more false positives like strings.Builder.WriteString
     - "G104: Errors unhandled"
+
+    # gosec: False positive triggered by `source, err := ioutil.ReadFile(f)`
+    - "G304: Potential file inclusion via variable"

internal/gofuzz/corpus.go

@@ -8,7 +8,7 @@
 package gofuzz
 
 import (
-	"crypto/sha1"
+	"crypto/sha1" //nolint:gosec // go-fuzz uses SHA1 for non-cryptographic hashing
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -39,6 +39,7 @@ func AddFileToCorpus(name string, data []byte) {
 
 // AddDataToCorpus adds unnamed Gosh source code fragment to the go-fuzz corpus.
 func AddDataToCorpus(prefix string, data []byte) {
-	name := fmt.Sprintf("%s-%040x.gosh", prefix, sha1.Sum(data))
+	// go-fuzz uses SHA1 for non-cryptographic hashing
+	name := fmt.Sprintf("%s-%040x.gosh", prefix, sha1.Sum(data)) //nolint:gosec
 	AddFileToCorpus(name, data)
 }

internal/golden/golden.go

@@ -40,7 +40,7 @@ func init() {
 		panic(err)
 	}
 	for _, f := range files {
-		source, err := ioutil.ReadFile(f) //nolint:gas
+		source, err := ioutil.ReadFile(f)
 		if err != nil {
 			panic(err)
 		}

main.go

@@ -54,7 +54,7 @@ func extractGoVersion(s string) string {
 }
 
 func goVersion() string {
-	cmd := exec.Command("go", "version") //nolint:gas
+	cmd := exec.Command("go", "version") //nolint:gosec
 	b, err := cmd.CombinedOutput()
 	if err != nil {
 		return ""