fix(sentinel): SentinelFeignClientProperties#copy() should fail fast on Jackson errors

spring-cloud-alibaba-starters/spring-cloud-circuitbreaker-sentinel/src/main/java/com/alibaba/cloud/circuitbreaker/sentinel/feign/SentinelFeignClientProperties.java

@@ -97,9 +97,10 @@ public SentinelFeignClientProperties copy() {
 			String json = objectMapper.writeValueAsString(this);
 			return objectMapper.readValue(json, this.getClass());
 		}
-		catch (Exception ignored) {
+		catch (Exception e) {
+			throw new IllegalStateException(
+					"Failed to deep-copy SentinelFeignClientProperties via Jackson", e);
 		}
-		return new SentinelFeignClientProperties();
 	}
 
 }

spring-cloud-alibaba-starters/spring-cloud-circuitbreaker-sentinel/src/test/java/com/alibaba/cloud/circuitbreaker/sentinel/feign/SentinelFeignClientPropertiesTest.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2013-present the original author or authors.
+ *
+ * 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 com.alibaba.cloud.circuitbreaker.sentinel.feign;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+/**
+ * Unit tests for {@link SentinelFeignClientProperties#copy()}.
+ */
+public class SentinelFeignClientPropertiesTest {
+
+	@Test
+	public void copyReturnsEqualButDistinctInstance() {
+		SentinelFeignClientProperties original = new SentinelFeignClientProperties();
+		original.setDefaultRule("custom-default");
+		original.setEnableRefreshRules(false);
+		Map<String, List<DegradeRule>> rules = new HashMap<>();
+		List<DegradeRule> ruleList = new ArrayList<>();
+		DegradeRule rule = new DegradeRule("resource-a");
+		rule.setCount(5.0);
+		ruleList.add(rule);
+		rules.put("resource-a", ruleList);
+		original.setRules(rules);
+
+		SentinelFeignClientProperties copied = original.copy();
+
+		assertThat(copied).isNotSameAs(original);
+		assertThat(copied).isEqualTo(original);
+	}
+
+	@Test
+	public void modifyingCopyDoesNotAffectOriginal() {
+		SentinelFeignClientProperties original = new SentinelFeignClientProperties();
+		Map<String, List<DegradeRule>> rules = new HashMap<>();
+		List<DegradeRule> ruleList = new ArrayList<>();
+		ruleList.add(new DegradeRule("resource-a"));
+		rules.put("resource-a", ruleList);
+		original.setRules(rules);
+
+		SentinelFeignClientProperties copied = original.copy();
+		copied.getRules().put("resource-b",
+				new ArrayList<>(List.of(new DegradeRule("resource-b"))));
+		copied.setDefaultRule("changed");
+
+		assertThat(original.getRules()).containsOnlyKeys("resource-a");
+		assertThat(original.getDefaultRule()).isEqualTo("default");
+	}
+
+	@Test
+	public void copyFailsFastWhenJacksonCannotSerialize() {
+		SentinelFeignClientProperties brokenProps = new SentinelFeignClientProperties() {
+			@Override
+			public Map<String, List<DegradeRule>> getRules() {
+				throw new RuntimeException("simulated serialization failure");
+			}
+		};
+
+		assertThatThrownBy(brokenProps::copy)
+				.isInstanceOf(IllegalStateException.class)
+				.hasMessageContaining("SentinelFeignClientProperties")
+				.hasCauseInstanceOf(RuntimeException.class);
+	}
+
+}