fix removeRegistryFromTag and add tests

Author: dobrac

packages/shared/pkg/dockerhub/repository.go

@@ -3,6 +3,7 @@ package dockerhub
 import (
 	"context"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/google/go-containerregistry/pkg/name"
@@ -59,7 +60,10 @@ func removeRegistryFromTag(tag string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("invalid image reference: %w", err)
 	}
-	refWithoutRegistry := ref.String()
 
-	return refWithoutRegistry, nil
+	registry := ref.Context().RegistryStr()
+	withoutRegistry := strings.TrimPrefix(ref.Name(), registry)
+	withoutRegistry = strings.TrimPrefix(withoutRegistry, "/")
+
+	return withoutRegistry, nil
 }

packages/shared/pkg/dockerhub/repository_test.go

@@ -0,0 +1,70 @@
+package dockerhub
+
+import (
+	"testing"
+)
+
+func TestRemoveRegistryFromTag(t *testing.T) {
+	tests := []struct {
+		name    string
+		tag     string
+		want    string
+		wantErr bool
+	}{
+		{
+			name:    "tag with registry prefix",
+			tag:     "docker.io/library/ubuntu:latest",
+			want:    "library/ubuntu:latest",
+			wantErr: false,
+		},
+		{
+			name:    "tag without registry",
+			tag:     "ubuntu:latest",
+			want:    "library/ubuntu:latest",
+			wantErr: false,
+		},
+		{
+			name:    "tag without registry",
+			tag:     "index.docker.io/ubuntu:latest",
+			want:    "library/ubuntu:latest",
+			wantErr: false,
+		},
+		{
+			name:    "tag with custom registry",
+			tag:     "gcr.io/my-project/my-image:v1.0.0",
+			want:    "my-project/my-image:v1.0.0",
+			wantErr: false,
+		},
+		{
+			name:    "tag with port in registry",
+			tag:     "localhost:5000/my-image:latest",
+			want:    "my-image:latest",
+			wantErr: false,
+		},
+		{
+			name:    "invalid tag format",
+			tag:     ":::invalid",
+			want:    "",
+			wantErr: true,
+		},
+		{
+			name:    "empty tag",
+			tag:     "",
+			want:    "",
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := removeRegistryFromTag(tt.tag)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("removeRegistryFromTag() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("removeRegistryFromTag() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}