fix proposer config loader (#8687)

* fix proposer config loader

CHANGELOG.md

@@ -11,3 +11,5 @@
 ### Additions and Improvements
 
 ### Bug Fixes
+- Fixed the proposer configuration file loading error at startup
+

validator/client/src/main/java/tech/pegasys/teku/validator/client/ValidatorClientService.java

@@ -16,7 +16,6 @@
 import static tech.pegasys.teku.infrastructure.exceptions.ExitConstants.FATAL_EXIT_CODE;
 import static tech.pegasys.teku.infrastructure.logging.StatusLogger.STATUS_LOG;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import java.net.http.HttpClient;
 import java.nio.file.Path;
 import java.time.Duration;
@@ -184,7 +183,7 @@ public static ValidatorClientService create(
           ProposerConfigProvider.create(
               asyncRunner,
               validatorConfig.getRefreshProposerConfigFromSource(),
-              new ProposerConfigLoader(new ObjectMapper()),
+              new ProposerConfigLoader(),
               services.getTimeProvider(),
               validatorConfig.getProposerConfigSource());
 

validator/client/src/main/java/tech/pegasys/teku/validator/client/proposerconfig/loader/ProposerConfigLoader.java

@@ -33,10 +33,10 @@
 import tech.pegasys.teku.validator.client.ProposerConfig;
 
 public class ProposerConfigLoader {
-  final ObjectMapper objectMapper;
+  private final ObjectMapper objectMapper;
 
   public ProposerConfigLoader() {
-    this(new ObjectMapper());
+    this.objectMapper = new ObjectMapper();
     addTekuMappers();
   }
 
@@ -50,8 +50,8 @@ private void addTekuMappers() {
     objectMapper.registerModule(module);
   }
 
-  public ProposerConfigLoader(final ObjectMapper objectMapper) {
-    this.objectMapper = objectMapper;
+  public ObjectMapper getObjectMapper() {
+    return this.objectMapper;
   }
 
   public ProposerConfig getProposerConfig(final URL source) {

validator/client/src/test/java/tech/pegasys/teku/validator/client/proposerconfig/loader/ProposerConfigLoaderTest.java

@@ -17,9 +17,15 @@
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.google.common.io.Resources;
 import java.net.URL;
+import java.util.Map;
 import java.util.Optional;
+import org.apache.tuweni.bytes.Bytes48;
 import org.junit.jupiter.api.Test;
 import tech.pegasys.teku.bls.BLSPublicKey;
 import tech.pegasys.teku.ethereum.execution.types.Eth1Address;
@@ -147,6 +153,40 @@ void shouldNotLoadBuilderOverridesWithPubKeyInDefaultConfig() {
             "\"publicKey\" is not allowed in \"default_config.builder.registrationOverrides\"");
   }
 
+  @Test
+  public void shouldRegisterRequiredSerializersAndDeserializers() throws JsonProcessingException {
+    final ProposerConfigLoader loader = new ProposerConfigLoader();
+    final ObjectMapper objectMapper = loader.getObjectMapper();
+
+    final SimpleModule module = new SimpleModule("ProposerConfigLoader");
+    assertThat(objectMapper.getRegisteredModuleIds()).contains(module.getTypeId());
+
+    // Can deserialize BLSPublicKey
+    final String pubKey =
+        "0xa057816155ad77931185101128655c0191bd0214c201ca48ed887f6c4c6adf334070efcd75140eada5ac83a92506dd7a";
+    final String pubKeyJson = String.format("\"%s\"", pubKey);
+    final BLSPublicKey pubKeyFromJson = objectMapper.readValue(pubKeyJson, BLSPublicKey.class);
+    assertThat(pubKeyFromJson).isNotNull();
+    assertThat(pubKeyFromJson.toString()).isEqualTo(pubKey);
+
+    // Can serialize BLSPublicKey
+    final BLSPublicKey blsPubKey = BLSPublicKey.fromHexString(pubKey);
+    final String jsonFromPubKey = objectMapper.writeValueAsString(blsPubKey);
+    assertThat(jsonFromPubKey).isEqualTo(pubKeyJson);
+
+    // Can deserialize Bytes48 map key
+    final Bytes48 key = Bytes48.fromHexString(pubKey);
+    final Map<Bytes48, String> originalMap = Map.of(key, "value");
+    // Serialize the map to JSON
+    final String json = objectMapper.writeValueAsString(originalMap);
+    // Deserialize the JSON back to a map
+    final Map<Bytes48, String> deserializedMap =
+        objectMapper.readValue(json, new TypeReference<>() {});
+
+    // Verify that the deserialized map matches the original
+    assertThat(deserializedMap).isEqualTo(originalMap);
+  }
+
   private void validateContent1(final ProposerConfig config) {
     final Optional<Config> theConfig =
         config.getConfigForPubKey(