style: enforce null-coalescing operator (#11461)

* Enforce null-coalescing operator instead of null check

* Fixes

Author: alexb5dh

.editorconfig

@@ -63,7 +63,7 @@ dotnet_naming_style.pascal_case.required_suffix =
 dotnet_naming_style.pascal_case.word_separator =
 dotnet_naming_style.pascal_case.capitalization = pascal_case
 dotnet_style_operator_placement_when_wrapping = beginning_of_line
-dotnet_style_coalesce_expression = true:suggestion
+dotnet_style_coalesce_expression = true:error
 dotnet_style_null_propagation = true:suggestion
 dotnet_style_prefer_is_null_check_over_reference_equality_method = true:suggestion
 dotnet_style_prefer_auto_properties = true:silent

src/Nethermind/Ethereum.Test.Base/TestLoader.cs

@@ -56,12 +56,8 @@ public static IEnumerable<TTest> LoadFromFile<TContainer, TTest>(
     {
         Assembly assembly = typeof(TTest).Assembly;
         string[] resourceNames = assembly.GetManifestResourceNames();
-        string resourceName = resourceNames.SingleOrDefault(r => r.Contains(testFileName));
-        if (resourceName is null)
-        {
-            throw new ArgumentException($"Cannot find test resource: {testFileName}");
-        }
-
+        string resourceName = resourceNames.SingleOrDefault(r => r.Contains(testFileName))
+            ?? throw new ArgumentException($"Cannot find test resource: {testFileName}");
         JsonSerializerOptions jsonOptions = new()
         {
             PropertyNameCaseInsensitive = true,

src/Nethermind/Nethermind.Consensus.Clique/SnapshotManager.cs

@@ -112,13 +112,11 @@ public Snapshot GetOrCreateSnapshot(long number, Hash256 hash)
 
                     // If we're at an checkpoint block, make a snapshot if it's known
                     BlockHeader? previousHeader = header;
-                    header = _blockTree.FindHeader(hash, BlockTreeLookupOptions.TotalDifficultyNotNeeded);
-                    if (header is null)
-                    {
-                        throw new InvalidOperationException($"Unknown ancestor ({hash}) of {previousHeader?.ToString(BlockHeader.Format.Short)}");
-                    }
+                    header = _blockTree.FindHeader(hash, BlockTreeLookupOptions.TotalDifficultyNotNeeded)
+                        ?? throw new InvalidOperationException($"Unknown ancestor ({hash}) of {previousHeader?.ToString(BlockHeader.Format.Short)}");
 
-                    if (header.Hash is null) throw new InvalidOperationException("Block tree block without hash set");
+                    if (header.Hash is null)
+                        throw new InvalidOperationException("Block tree block without hash set");
 
                     Hash256 parentHash = header.ParentHash;
                     if (IsEpochTransition(number))

src/Nethermind/Nethermind.Consensus/Stateless/WitnessCapturingTrieStore.cs

@@ -30,12 +30,9 @@ public TrieNode FindCachedOrUnknown(Hash256? address, in TreePath path, Hash256
         return node;
     }
 
-    public byte[]? LoadRlp(Hash256? address, in TreePath path, Hash256 hash, ReadFlags flags = ReadFlags.None)
-    {
-        byte[]? rlp = TryLoadRlp(address, in path, hash, flags);
-        if (rlp is null) throw new MissingTrieNodeException("Missing RLP node", address, path, hash);
-        return rlp;
-    }
+    public byte[]? LoadRlp(Hash256? address, in TreePath path, Hash256 hash, ReadFlags flags = ReadFlags.None) =>
+        TryLoadRlp(address, in path, hash, flags)
+        ?? throw new MissingTrieNodeException("Missing RLP node", address, path, hash);
 
     public byte[]? TryLoadRlp(Hash256? address, in TreePath path, Hash256 hash, ReadFlags flags = ReadFlags.None)
     {

src/Nethermind/Nethermind.Core/Container/FallbackToFieldFromApi.cs

@@ -80,12 +80,8 @@ public IEnumerable<IComponentRegistration> RegistrationsFor(Service service, Fun
         IRegistrationBuilder<object, SimpleActivatorData, SingleRegistrationStyle> builder = RegistrationBuilder.ForDelegate(serviceType, (ctx, reg) =>
         {
             TApi baseT = ctx.Resolve<TApi>();
-            object? value = property.GetValue(baseT);
-            if (value is null)
-            {
-                throw new MissingFieldException($"Property {property.Name} in {baseT.GetType().Name} is null");
-            }
-            return value!;
+            return property.GetValue(baseT)
+                ?? throw new MissingFieldException($"Property {property.Name} in {baseT.GetType().Name} is null");
         })
             .WithMetadata(FallbackMetadata, true)
             .ExternallyOwned();

src/Nethermind/Nethermind.Era1/EraExporter.cs

@@ -115,11 +115,8 @@ async Task WriteEpoch(long epochIdx)
             {
                 for (long y = startingIndex; y < startingIndex + _era1Size && y <= to; y++)
                 {
-                    Block? block = blockTree.FindBlock(y, BlockTreeLookupOptions.DoNotCreateLevelIfMissing);
-                    if (block is null)
-                    {
-                        throw new EraException($"Could not find a block with number {y}.");
-                    }
+                    Block? block = blockTree.FindBlock(y, BlockTreeLookupOptions.DoNotCreateLevelIfMissing)
+                        ?? throw new EraException($"Could not find a block with number {y}.");
 
                     TxReceipt[]? receipts = receiptStorage.Get(block, true, false);
                     if (receipts is null || (block.Header.ReceiptsRoot != Keccak.EmptyTreeHash && receipts.Length == 0))

src/Nethermind/Nethermind.EraE/Export/EraExporter.cs

@@ -56,12 +56,8 @@ public Task Export(string destinationPath, long from, long to, CancellationToken
         if (from > to)
             throw new ArgumentException($"Start block ({from}) must not be after end block ({to}).");
 
-        Block? lastBlock = blockTree.FindBlock(to, BlockTreeLookupOptions.DoNotCreateLevelIfMissing);
-        if (lastBlock is null)
-            throw new InvalidOperationException(
-                $"Block {to} is not available. " +
-                "EraE export requires all block bodies to be present. " +
-                "Ensure the node is fully synced before exporting.");
+        _ = blockTree.FindBlock(to, BlockTreeLookupOptions.DoNotCreateLevelIfMissing)
+            ?? throw new InvalidOperationException($"Block {to} is not available. EraE export requires all block bodies to be present. Ensure the node is fully synced before exporting.");
 
         return DoExport(destinationPath, from, to, cancellation);
     }
@@ -139,9 +135,8 @@ async Task WriteEpoch(long epochIdx, CancellationToken cancel)
             {
                 for (long blockNumber = writeFrom; blockNumber <= writeTo; blockNumber++)
                 {
-                    Block? block = blockTree.FindBlock(blockNumber, BlockTreeLookupOptions.DoNotCreateLevelIfMissing);
-                    if (block is null)
-                        throw new EraException($"Could not find block {blockNumber}. The node may not have finished syncing block bodies for this range.");
+                    Block block = blockTree.FindBlock(blockNumber, BlockTreeLookupOptions.DoNotCreateLevelIfMissing)
+                        ?? throw new EraException($"Could not find block {blockNumber}. The node may not have finished syncing block bodies for this range.");
 
                     // IsPostMerge is not part of the RLP encoding and defaults to false when read from
                     // the block store. Restore it from Difficulty (EIP-3675: post-merge Difficulty == 0).

src/Nethermind/Nethermind.Init/Steps/InitializeBlockProducer.cs

@@ -31,12 +31,8 @@ public Task Execute(CancellationToken _)
                 return Task.CompletedTask;
             }
 
-            IConsensusPlugin? consensusPlugin = _api.GetConsensusPlugin();
-            if (consensusPlugin is null)
-            {
-                throw new NotSupportedException($"Mining in {_api.ChainSpec.SealEngineType} mode is not supported");
-            }
-
+            IConsensusPlugin consensusPlugin = _api.GetConsensusPlugin()
+                ?? throw new NotSupportedException($"Mining in {_api.ChainSpec.SealEngineType} mode is not supported");
             IBlockProducerFactory blockProducerFactory = consensusPlugin;
             IBlockProducerRunnerFactory blockProducerRunnerFactory = consensusPlugin;
 

src/Nethermind/Nethermind.Serialization.Rlp/Rlp.cs

@@ -1379,14 +1379,9 @@ public byte DecodeByte()
 
             public T[] DecodeArray<T>(IRlpValueDecoder<T>? decoder = null, bool checkPositions = true, T defaultElement = default, RlpLimit? limit = null)
             {
-                if (decoder is null)
-                {
-                    decoder = GetValueDecoder<T>();
-                    if (decoder is null)
-                    {
-                        throw new RlpException($"{nameof(Rlp)} does not support length of {nameof(T)}");
-                    }
-                }
+                decoder ??= GetValueDecoder<T>()
+                    ?? throw new RlpException($"{nameof(Rlp)} does not support length of {nameof(T)}");
+
                 int positionCheck = ReadSequenceLength() + Position;
                 int count = PeekNumberOfItemsRemaining(checkPositions ? positionCheck : null);
                 GuardLimit(count, limit);

src/Nethermind/Nethermind.State.Flat/FlatStateReader.cs

@@ -56,11 +56,8 @@ public void RunTreeVisitor<TCtx>(ITreeVisitor<TCtx> treeVisitor, BlockHeader? ba
     {
         StateId stateId = new(baseBlock);
 
-        using ReadOnlySnapshotBundle? reader = flatDbManager.GatherReadOnlySnapshotBundle(stateId);
-        if (reader is null)
-        {
-            throw new InvalidOperationException($"State at {baseBlock} not found");
-        }
+        using ReadOnlySnapshotBundle reader = flatDbManager.GatherReadOnlySnapshotBundle(stateId)
+            ?? throw new InvalidOperationException($"State at {baseBlock} not found");
 
         ReadOnlyStateTrieStoreAdapter trieStoreAdapter = new(reader);