Exclude domain from name length check

Signed-off-by: Ozair <ozair.asim@docker.com>

reference.go

@@ -35,8 +35,13 @@ import (
 )
 
 const (
+	// RepositoryNameTotalLengthMax is the maximum total number of characters in a repository name.
+	RepositoryNameTotalLengthMax = 255
+
 	// NameTotalLengthMax is the maximum total number of characters in a repository name.
-	NameTotalLengthMax = 255
+	//
+	// Deprecated: use [RepositoryNameTotalLengthMax] instead.
+	NameTotalLengthMax = RepositoryNameTotalLengthMax
 )
 
 var (
@@ -55,8 +60,8 @@ var (
 	// ErrNameEmpty is returned for empty, invalid repository names.
 	ErrNameEmpty = errors.New("repository name must have at least one component")
 
-	// ErrNameTooLong is returned when a repository name is longer than NameTotalLengthMax.
-	ErrNameTooLong = fmt.Errorf("repository name must not be more than %v characters", NameTotalLengthMax)
+	// ErrNameTooLong is returned when a repository name is longer than RepositoryNameTotalLengthMax.
+	ErrNameTooLong = fmt.Errorf("repository name must not be more than %v characters", RepositoryNameTotalLengthMax)
 
 	// ErrNameNotCanonical is returned when a name is not canonical.
 	ErrNameNotCanonical = errors.New("repository name must be canonical")
@@ -190,10 +195,6 @@ func Parse(s string) (Reference, error) {
 		return nil, ErrReferenceInvalidFormat
 	}
 
-	if len(matches[1]) > NameTotalLengthMax {
-		return nil, ErrNameTooLong
-	}
-
 	var repo repository
 
 	nameMatch := anchoredNameRegexp.FindStringSubmatch(matches[1])
@@ -205,6 +206,10 @@ func Parse(s string) (Reference, error) {
 		repo.path = matches[1]
 	}
 
+	if len(repo.path) > RepositoryNameTotalLengthMax {
+		return nil, ErrNameTooLong
+	}
+
 	ref := reference{
 		namedRepository: repo,
 		tag:             matches[2],
@@ -243,14 +248,15 @@ func ParseNamed(s string) (Named, error) {
 // WithName returns a named object representing the given string. If the input
 // is invalid ErrReferenceInvalidFormat will be returned.
 func WithName(name string) (Named, error) {
-	if len(name) > NameTotalLengthMax {
-		return nil, ErrNameTooLong
-	}
-
 	match := anchoredNameRegexp.FindStringSubmatch(name)
 	if match == nil || len(match) != 3 {
 		return nil, ErrReferenceInvalidFormat
 	}
+
+	if len(match[2]) > RepositoryNameTotalLengthMax {
+		return nil, ErrNameTooLong
+	}
+
 	return repository{
 		domain: match[1],
 		path:   match[2],

reference_test.go

@@ -4,6 +4,7 @@ import (
 	_ "crypto/sha256"
 	_ "crypto/sha512"
 	"encoding/json"
+	"errors"
 	"strings"
 	"testing"
 
@@ -117,7 +118,7 @@ func TestReferenceParse(t *testing.T) {
 			tag:        "Uppercase",
 		},
 		{
-			input: strings.Repeat("a/", 128) + "a:tag",
+			input: "domain/" + strings.Repeat("a", 256) + ":tag",
 			err:   ErrNameTooLong,
 		},
 		{
@@ -266,6 +267,12 @@ func TestReferenceParse(t *testing.T) {
 			input: "[fe80::1%@invalidzone]:5000/repo",
 			err:   ErrReferenceInvalidFormat,
 		},
+		{
+			input:      "example.com/" + strings.Repeat("a", 255) + ":tag",
+			domain:     "example.com",
+			repository: "example.com/" + strings.Repeat("a", 255),
+			tag:        "tag",
+		},
 	}
 	for _, tc := range tests {
 		tc := tc
@@ -337,7 +344,7 @@ func TestWithNameFailure(t *testing.T) {
 	}{
 		{
 			input: "",
-			err:   ErrNameEmpty,
+			err:   ErrReferenceInvalidFormat,
 		},
 		{
 			input: ":justtag",
@@ -352,7 +359,11 @@ func TestWithNameFailure(t *testing.T) {
 			err:   ErrReferenceInvalidFormat,
 		},
 		{
-			input: strings.Repeat("a/", 128) + "a:tag",
+			input: "example.com/repo:tag",
+			err:   ErrReferenceInvalidFormat,
+		},
+		{
+			input: "example.com/" + strings.Repeat("a", 256),
 			err:   ErrNameTooLong,
 		},
 		{
@@ -365,8 +376,8 @@ func TestWithNameFailure(t *testing.T) {
 		t.Run(tc.input, func(t *testing.T) {
 			t.Parallel()
 			_, err := WithName(tc.input)
-			if err == nil {
-				t.Errorf("no error parsing name. expected: %s", tc.err)
+			if !errors.Is(err, tc.err) {
+				t.Errorf("unexpected error parsing name. expected: %s, got: %s", tc.err, err)
 			}
 		})
 	}