[HUDI-2818] Fix 2to3 upgrade when set hoodie.table.keygenerator.class (#4077)

hudi-client/hudi-client-common/src/test/java/org/apache/hudi/table/upgrade/TestTwoToThreeUpgradeHandler.java

@@ -0,0 +1,68 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.hudi.table.upgrade;
+
+import org.apache.hudi.common.config.ConfigProperty;
+import org.apache.hudi.common.config.HoodieMetadataConfig;
+import org.apache.hudi.common.table.HoodieTableConfig;
+import org.apache.hudi.config.HoodieWriteConfig;
+import org.apache.hudi.keygen.KeyGenerator;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class TestTwoToThreeUpgradeHandler {
+
+  HoodieWriteConfig config;
+
+  @BeforeEach
+  void setUp() {
+    config = HoodieWriteConfig.newBuilder()
+        .forTable("foo")
+        .withPath("/foo")
+        .withMetadataConfig(HoodieMetadataConfig.newBuilder().enable(false).build())
+        .build();
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"hoodie.table.keygenerator.class", "hoodie.datasource.write.keygenerator.class"})
+  void upgradeHandlerShouldRetrieveKeyGeneratorConfig(String keyGenConfigKey) {
+    config.setValue(keyGenConfigKey, KeyGenerator.class.getName());
+    TwoToThreeUpgradeHandler handler = new TwoToThreeUpgradeHandler();
+    Map<ConfigProperty, String> kv = handler.upgrade(config, null, null, null);
+    assertEquals(KeyGenerator.class.getName(), kv.get(HoodieTableConfig.KEY_GENERATOR_CLASS_NAME));
+  }
+
+  @Test
+  void upgradeHandlerShouldThrowWhenKeyGeneratorNotSet() {
+    TwoToThreeUpgradeHandler handler = new TwoToThreeUpgradeHandler();
+    Throwable t = assertThrows(IllegalStateException.class, () -> handler
+        .upgrade(config, null, null, null));
+    assertTrue(t.getMessage().startsWith("Missing config:"));
+  }
+}