Simpler md5 parsing

Signed-off-by: Sebastian Rabenhorst <[email protected]>

Author: rabenhorst

clientutil/parse.go

@@ -66,14 +66,15 @@ func ParseLastModified(m http.Header, f string) (time.Time, error) {
 	return mod, nil
 }
 
-// ParseMD5 returns the bytes parsed from the hex-encoded MD5 string.
+// ParseMD5 returns the bytes parsed from the hex-encoded MD5 string
 // It trims potential surrounding double quotes before decoding.
-func ParseMD5(md5Hex string) ([]byte, error) {
+// It returns nil if the MD5 string is not valid.
+func ParseMD5(md5Hex string) []byte {
 	// Trim surrounding double quotes if present.
 	trimmed := strings.Trim(md5Hex, "\"")
-	decoded, err := hex.DecodeString(trimmed)
-	if err != nil {
-		return nil, errors.Wrapf(err, "decode hex MD5 string: %s", md5Hex)
+	decoded, _ := hex.DecodeString(trimmed)
+	if len(decoded) != 16 {
+		return nil
 	}
-	return decoded, nil
+	return decoded
 }

clientutil/parse_test.go

@@ -116,7 +116,6 @@ func TestParseMD5(t *testing.T) {
 		label string
 		in    string
 		out   []byte
-		err   string
 	}{
 		{
 			label: "valid md5",
@@ -126,12 +125,10 @@ func TestParseMD5(t *testing.T) {
 		{
 			label: "invalid hex string",
 			in:    "not-a-hex-string",
-			err:   "decode hex MD5 string: not-a-hex-string: encoding/hex: invalid byte: U+006E 'n'",
 		},
 		{
 			label: "odd length hex string",
 			in:    "abc",
-			err:   "decode hex MD5 string: abc: encoding/hex: odd length hex string",
 		},
 		{
 			label: "empty string",
@@ -146,7 +143,6 @@ func TestParseMD5(t *testing.T) {
 		{
 			label: "invalid hex string with quotes",
 			in:    "\"not-a-hex-string\"",
-			err:   "decode hex MD5 string: \"not-a-hex-string\": encoding/hex: invalid byte: U+006E 'n'",
 		},
 		{
 			label: "only quotes",
@@ -155,14 +151,8 @@ func TestParseMD5(t *testing.T) {
 		},
 	} {
 		t.Run(tc.label, func(t *testing.T) {
-			out, err := ParseMD5(tc.in)
-			if tc.err != "" {
-				testutil.Assert(t, err.Error() == tc.err, fmt.Sprintf("error message mismatch: %s != %s", err.Error(), tc.err))
-				testutil.Assert(t, out == nil, "output should be nil")
-			} else {
-				testutil.Ok(t, err)
-				testutil.Assert(t, bytes.Equal(out, tc.out), fmt.Sprintf("output mismatch: %v != %v", out, tc.out))
-			}
+			out := ParseMD5(tc.in)
+			testutil.Assert(t, bytes.Equal(out, tc.out), fmt.Sprintf("output mismatch: %v != %v", out, tc.out))
 		})
 	}
 }