replaceRegistry unit tests

Signed-off-by: Brooks Newberry <[email protected]>

registry/registry.go

@@ -32,17 +32,21 @@ func NewClient(registry string, debug bool) *Client {
 	return &Client{registry}
 }
 
+func replaceRegistry(registry string, ref name.Reference) (name.Tag, error) {
+	newRef, err := name.NewRepository(registry + "/" + ref.Context().RepositoryStr())
+	if err != nil {
+		return name.Tag{}, err
+	}
+
+	return name.NewTag(newRef.String() + ":" + ref.Identifier())
+}
+
 func (c *Client) Image(ctx context.Context, ref name.Reference) (Image, error) {
 	info := Image{
 		Platforms: make(map[Platform]bool),
 	}
 
-	newRef, err := name.NewRepository(c.registry + "/" + ref.Context().RepositoryStr())
-	if err != nil {
-		return info, err
-	}
-
-	tagRef, err := name.NewTag(newRef.String() + ":" + ref.Identifier())
+	tagRef, err := replaceRegistry(c.registry, ref)
 	if err != nil {
 		return info, err
 	}

registry/registry_test.go

@@ -0,0 +1,51 @@
+package registry
+
+import (
+	"testing"
+
+	"github.com/google/go-containerregistry/pkg/name"
+)
+
+func TestReplaceRegistry(t *testing.T) {
+	tests := []struct {
+		name      string
+		registry  string
+		inputRef  string
+		expected  string
+		expectErr bool
+	}{
+		{
+			name:      "replace docker.io registry",
+			registry:  "custom.registry.io",
+			inputRef:  "docker.io/library/nginx:latest",
+			expected:  "custom.registry.io/library/nginx:latest",
+			expectErr: false,
+		},
+		{
+			name:      "handle docker library images",
+			registry:  "custom.registry.io",
+			inputRef:  "hello-world",
+			expected:  "custom.registry.io/library/hello-world:latest",
+			expectErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ref, err := name.ParseReference(tt.inputRef)
+			if err != nil {
+				t.Fatalf("failed to parse input reference: %v", err)
+			}
+
+			result, err := replaceRegistry(tt.registry, ref)
+			if (err != nil) != tt.expectErr {
+				t.Errorf("replaceRegistry() error = %v, expectErr %v", err, tt.expectErr)
+				return
+			}
+
+			if !tt.expectErr && result.Name() != tt.expected {
+				t.Errorf("replaceRegistry() = %v, want %v", result.Name(), tt.expected)
+			}
+		})
+	}
+}