Do not return errors when no account is present, return a zero balance instead (#1951)

Signed-off-by: Antoine Toulme <antoine@lunar-ocean.com>

CHANGELOG.md

@@ -9,6 +9,7 @@
 
 ### Bug Fixes
 * Fixed incorrect `groupId` in published maven pom files.
+* Fixed GraphQL response for missing account, return empty account instead [\#1946](https://github.com/hyperledger/besu/issues/1946)
 
 ### Early Access Features
 

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/graphql/GraphQLDataFetchers.java

@@ -17,6 +17,7 @@ package org.hyperledger.besu.ethereum.api.graphql;
 import static com.google.common.base.Preconditions.checkArgument;
 
 import org.hyperledger.besu.ethereum.api.graphql.internal.pojoadapter.AccountAdapter;
+import org.hyperledger.besu.ethereum.api.graphql.internal.pojoadapter.EmptyAccountAdapter;
 import org.hyperledger.besu.ethereum.api.graphql.internal.pojoadapter.LogAdapter;
 import org.hyperledger.besu.ethereum.api.graphql.internal.pojoadapter.NormalBlockAdapter;
 import org.hyperledger.besu.ethereum.api.graphql.internal.pojoadapter.PendingStateAdapter;
@@ -186,8 +187,9 @@ public class GraphQLDataFetchers {
         final Optional<WorldState> ws = blockchainQuery.getWorldState(bn);
         if (ws.isPresent()) {
           final Account account = ws.get().get(addr);
-          Preconditions.checkArgument(
-              account != null, "Account with address %s does not exist", addr);
+          if (account == null) {
+            return Optional.of(new EmptyAccountAdapter(addr));
+          }
           return Optional.of(new AccountAdapter(account));
         } else if (bn > blockchainQuery.getBlockchain().getChainHeadBlockNumber()) {
           // block is past chainhead
@@ -201,13 +203,13 @@ public class GraphQLDataFetchers {
         final long latestBn = blockchainQuery.latestBlock().get().getHeader().getNumber();
         final Optional<WorldState> ows = blockchainQuery.getWorldState(latestBn);
         return ows.flatMap(
-                ws -> {
-                  Account account = ws.get(addr);
-                  Preconditions.checkArgument(
-                      account != null, "Account with address %s does not exist", addr);
-                  return Optional.ofNullable(account);
-                })
-            .map(AccountAdapter::new);
+            ws -> {
+              Account account = ws.get(addr);
+              if (account == null) {
+                return Optional.of(new EmptyAccountAdapter(addr));
+              }
+              return Optional.of(new AccountAdapter(account));
+            });
       }
     };
   }

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/graphql/internal/pojoadapter/EmptyAccountAdapter.java

@@ -23,30 +23,35 @@ import graphql.schema.DataFetchingEnvironment;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
 
-@SuppressWarnings("unused") // reflected by GraphQL
-public class EmptyAccountAdapter extends AdapterBase {
+public class EmptyAccountAdapter extends AccountAdapter {
   private final Address address;
 
   public EmptyAccountAdapter(final Address address) {
+    super(null);
     this.address = address;
   }
 
+  @Override
   public Optional<Address> getAddress() {
     return Optional.of(address);
   }
 
+  @Override
   public Optional<Wei> getBalance() {
     return Optional.of(Wei.ZERO);
   }
 
+  @Override
   public Optional<Long> getTransactionCount() {
     return Optional.of(0L);
   }
 
+  @Override
   public Optional<Bytes> getCode() {
     return Optional.of(Bytes.EMPTY);
   }
 
+  @Override
   public Optional<Bytes32> getStorage(final DataFetchingEnvironment environment) {
     return Optional.of(Bytes32.ZERO);
   }

ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/graphql/eth_getBalance_invalidAccountBlockNumber.json

@@ -1,25 +1,12 @@
 {
   "request": "{account(blockNumber:\"0x19\", address: \"0xdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef\") { balance } }",
   "response": {
-    "errors": [
-      {
-        "message": "Exception while fetching data (/account) : Account with address 0xdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef does not exist",
-        "locations": [
-          {
-            "line": 1,
-            "column": 2
-          }
-        ],
-        "path": [
-          "account"
-        ],
-        "extensions": {
-          "classification": "DataFetchingException"
-        }
+    "data": {
+      "account": {
+        "balance": "0x"
       }
-    ],
-    "data": null
+    }
   },
-  "statusCode": 400
+  "statusCode": 200
 }
 

ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/graphql/eth_getBalance_invalidAccountLatest.json

@@ -1,25 +1,12 @@
 {
   "request": "{account(address: \"0xdeaff00ddeaff00ddeaff00ddeaff00ddeaff00d\") { balance } }",
   "response": {
-    "errors": [
-      {
-        "message": "Exception while fetching data (/account) : Account with address 0xdeaff00ddeaff00ddeaff00ddeaff00ddeaff00d does not exist",
-        "locations": [
-          {
-            "line": 1,
-            "column": 2
-          }
-        ],
-        "path": [
-          "account"
-        ],
-        "extensions": {
-          "classification": "DataFetchingException"
-        }
+    "data" : {
+      "account" : {
+        "balance" : "0x"
       }
-    ],
-    "data": null
+    }
   },
-  "statusCode": 400
+  "statusCode": 200
 }