Revert "feat: drop node target's key constraint requirement (#2068)"

v2/googlecloud-to-neo4j/src/main/java/com/google/cloud/teleport/v2/neo4j/model/validation/NodeKeyValidator.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2024 Google LLC
+ *
+ * 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
+ *
+ *   http://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 com.google.cloud.teleport.v2.neo4j.model.validation;
+
+import java.util.LinkedHashSet;
+import java.util.Set;
+import org.neo4j.importer.v1.targets.NodeTarget;
+import org.neo4j.importer.v1.validation.SpecificationValidationResult.Builder;
+import org.neo4j.importer.v1.validation.SpecificationValidator;
+
+public class NodeKeyValidator implements SpecificationValidator {
+
+  private static final String ERROR_CODE = "DFNK-001";
+  private final Set<String> paths;
+
+  public NodeKeyValidator() {
+    this.paths = new LinkedHashSet<>();
+  }
+
+  @Override
+  public void visitNodeTarget(int index, NodeTarget target) {
+    var schema = target.getSchema();
+    if (schema == null) {
+      paths.add(String.format("$.targets.nodes[%d].schema.key_constraints", index));
+      return;
+    }
+    if (schema.getKeyConstraints().isEmpty()) {
+      paths.add(String.format("$.targets.nodes[%d].schema.key_constraints", index));
+    }
+  }
+
+  @Override
+  public boolean report(Builder builder) {
+    paths.forEach(
+        path ->
+            builder.addError(
+                path, ERROR_CODE, String.format("%s must define at least 1 key constraint", path)));
+    return paths.isEmpty();
+  }
+}

v2/googlecloud-to-neo4j/src/main/resources/META-INF/services/org.neo4j.importer.v1.validation.SpecificationValidator

@@ -3,6 +3,7 @@ com.google.cloud.teleport.v2.neo4j.model.validation.BigQuerySourceProjectDataset
 com.google.cloud.teleport.v2.neo4j.model.validation.DuplicateAggregateFieldNameValidator
 com.google.cloud.teleport.v2.neo4j.model.validation.DuplicateTextHeaderValidator
 com.google.cloud.teleport.v2.neo4j.model.validation.InlineSourceDataValidator
+com.google.cloud.teleport.v2.neo4j.model.validation.NodeKeyValidator
 com.google.cloud.teleport.v2.neo4j.model.validation.TextColumnMappingValidator
 com.google.cloud.teleport.v2.neo4j.model.validation.WriteModeValidator
 com.google.cloud.teleport.v2.neo4j.model.validation.NodeMatchModeValidator