Add comprehensive tests for ACR registry validation

Co-authored-by: Skarlso <182850+Skarlso@users.noreply.github.com>

pkg/generator/acr/acr_validation_test.go

@@ -0,0 +1,102 @@
+/*
+Copyright © 2025 ESO Maintainer Team
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package acr
+
+import (
+	"testing"
+)
+
+func TestValidateACRRegistry(t *testing.T) {
+	tests := []struct {
+		name      string
+		registry  string
+		wantError bool
+	}{
+		{
+			name:      "valid registry - .io",
+			registry:  "myregistry.azurecr.io",
+			wantError: false,
+		},
+		{
+			name:      "valid registry - .cn",
+			registry:  "myregistry.azurecr.cn",
+			wantError: false,
+		},
+		{
+			name:      "valid registry - .de",
+			registry:  "myregistry.azurecr.de",
+			wantError: false,
+		},
+		{
+			name:      "valid registry - .us",
+			registry:  "myregistry.azurecr.us",
+			wantError: false,
+		},
+		{
+			name:      "valid registry - with dashes",
+			registry:  "my-registry-name.azurecr.io",
+			wantError: false,
+		},
+		{
+			name:      "invalid registry - empty",
+			registry:  "",
+			wantError: true,
+		},
+		{
+			name:      "invalid registry - SSRF attempt localhost",
+			registry:  "localhost",
+			wantError: true,
+		},
+		{
+			name:      "invalid registry - SSRF attempt IP",
+			registry:  "192.168.1.1",
+			wantError: true,
+		},
+		{
+			name:      "invalid registry - wrong domain",
+			registry:  "myregistry.example.com",
+			wantError: true,
+		},
+		{
+			name:      "invalid registry - wrong TLD",
+			registry:  "myregistry.azurecr.com",
+			wantError: true,
+		},
+		{
+			name:      "invalid registry - missing domain",
+			registry:  "azurecr.io",
+			wantError: true,
+		},
+		{
+			name:      "invalid registry - uppercase",
+			registry:  "MyRegistry.azurecr.io",
+			wantError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateACRRegistry(tt.registry)
+			if tt.wantError && err == nil {
+				t.Errorf("validateACRRegistry() expected error but got none for registry: %s", tt.registry)
+			}
+			if !tt.wantError && err != nil {
+				t.Errorf("validateACRRegistry() unexpected error: %v for registry: %s", err, tt.registry)
+			}
+		})
+	}
+}