Unexport NewErrBadName and remove IsErrBadName

pkg/name/check.go

@@ -35,9 +35,9 @@ func stripRunesFn(runes string) func(rune) rune {
 func checkElement(name, element, allowedRunes string, minRunes, maxRunes int) error {
 	numRunes := utf8.RuneCountInString(element)
 	if (numRunes < minRunes) || (maxRunes < numRunes) {
-		return NewErrBadName("%s must be between %d and %d runes in length: %s", name, minRunes, maxRunes, element)
+		return newErrBadName("%s must be between %d and %d runes in length: %s", name, minRunes, maxRunes, element)
 	} else if len(strings.Map(stripRunesFn(allowedRunes), element)) != 0 {
-		return NewErrBadName("%s can only contain the runes `%s`: %s", name, allowedRunes, element)
+		return newErrBadName("%s can only contain the runes `%s`: %s", name, allowedRunes, element)
 	}
 	return nil
 }

pkg/name/digest.go

@@ -69,7 +69,7 @@ func NewDigest(name string, opts ...Option) (Digest, error) {
 	// Split on "@"
 	parts := strings.Split(name, digestDelim)
 	if len(parts) != 2 {
-		return Digest{}, NewErrBadName("a digest must contain exactly one '@' separator (e.g. registry/repository@digest) saw: %s", name)
+		return Digest{}, newErrBadName("a digest must contain exactly one '@' separator (e.g. registry/repository@digest) saw: %s", name)
 	}
 	base := parts[0]
 	digest := parts[1]

pkg/name/errors.go

@@ -15,7 +15,6 @@
 package name
 
 import (
-	"errors"
 	"fmt"
 )
 
@@ -28,13 +27,7 @@ func (e *ErrBadName) Error() string {
 	return e.info
 }
 
-// NewErrBadName returns a ErrBadName which returns the given formatted string from Error().
-func NewErrBadName(fmtStr string, args ...interface{}) *ErrBadName {
+// newErrBadName returns a ErrBadName which returns the given formatted string from Error().
+func newErrBadName(fmtStr string, args ...interface{}) *ErrBadName {
 	return &ErrBadName{fmt.Sprintf(fmtStr, args...)}
 }
-
-// IsErrBadName returns true if the given error is an ErrBadName.
-func IsErrBadName(err error) bool {
-	var berr *ErrBadName
-	return errors.As(err, &berr)
-}

pkg/name/errors_test.go

@@ -15,13 +15,15 @@
 package name
 
 import (
+	"errors"
 	"testing"
 )
 
 func TestBadName(t *testing.T) {
 	_, err := ParseReference("@@")
-	if !IsErrBadName(err) {
-		t.Errorf("IsBadErrName == false: %v", err)
+	var berr *ErrBadName
+	if !errors.As(err, &berr) {
+		t.Errorf("Not an ErrBadName: %v", err)
 	}
 	if err.Error() != "could not parse reference: @@" {
 		t.Errorf("Unexpected string: %v", err)

pkg/name/ref.go

@@ -44,7 +44,7 @@ func ParseReference(s string, opts ...Option) (Reference, error) {
 	if d, err := NewDigest(s, opts...); err == nil {
 		return d, nil
 	}
-	return nil, NewErrBadName("could not parse reference: " + s)
+	return nil, newErrBadName("could not parse reference: " + s)
 }
 
 type stringConst string

pkg/name/registry.go

@@ -98,7 +98,7 @@ func checkRegistry(name string) error {
 	// Per RFC 3986, registries (authorities) are required to be prefixed with "//"
 	// url.Host == hostname[:port] == authority
 	if url, err := url.Parse("//" + name); err != nil || url.Host != name {
-		return NewErrBadName("registries must be valid RFC 3986 URI authorities: %s", name)
+		return newErrBadName("registries must be valid RFC 3986 URI authorities: %s", name)
 	}
 	return nil
 }
@@ -108,7 +108,7 @@ func checkRegistry(name string) error {
 func NewRegistry(name string, opts ...Option) (Registry, error) {
 	opt := makeOptions(opts...)
 	if opt.strict && len(name) == 0 {
-		return Registry{}, NewErrBadName("strict validation requires the registry to be explicitly defined")
+		return Registry{}, newErrBadName("strict validation requires the registry to be explicitly defined")
 	}
 
 	if err := checkRegistry(name); err != nil {

pkg/name/repository.go

@@ -72,7 +72,7 @@ func checkRepository(repository string) error {
 func NewRepository(name string, opts ...Option) (Repository, error) {
 	opt := makeOptions(opts...)
 	if len(name) == 0 {
-		return Repository{}, NewErrBadName("a repository name must be specified")
+		return Repository{}, newErrBadName("a repository name must be specified")
 	}
 
 	var registry string
@@ -95,7 +95,7 @@ func NewRepository(name string, opts ...Option) (Repository, error) {
 		return Repository{}, err
 	}
 	if hasImplicitNamespace(repo, reg) && opt.strict {
-		return Repository{}, NewErrBadName("strict validation requires the full repository path (missing 'library')")
+		return Repository{}, newErrBadName("strict validation requires the full repository path (missing 'library')")
 	}
 	return Repository{reg, repo}, nil
 }

pkg/name/repository_test.go

@@ -15,6 +15,7 @@
 package name
 
 import (
+	"errors"
 	"strings"
 	"testing"
 )
@@ -116,8 +117,9 @@ func TestRepositoryScopes(t *testing.T) {
 }
 
 func TestRepositoryBadDefaulting(t *testing.T) {
-	if _, err := NewRepository("index.docker.io/foo", StrictValidation); !IsErrBadName(err) {
-		t.Errorf("IsBadErrName == false: %v", err)
+	var berr *ErrBadName
+	if _, err := NewRepository("index.docker.io/foo", StrictValidation); !errors.As(err, &berr) {
+		t.Errorf("Not an ErrBadName: %v", err)
 	}
 }
 

pkg/v1/remote/descriptor_test.go

@@ -69,8 +69,7 @@ func TestGetSchema1(t *testing.T) {
 	want := `unsupported MediaType: "application/vnd.docker.distribution.manifest.v1+prettyjws", see https://github.com/google/go-containerregistry/issues/377`
 	// Should fail based on media type.
 	if _, err := desc.Image(); err != nil {
-		var s1err ErrSchema1
-		if errors.Is(err, &s1err) {
+		if errors.Is(err, &ErrSchema1{}) {
 			t.Errorf("Image() = %v, expected remote.ErrSchema1", err)
 		}
 		if diff := cmp.Diff(want, err.Error()); diff != "" {