Use collection expressions

YamlDotNet/Core/Constants.cs

@@ -29,10 +29,10 @@ namespace YamlDotNet.Core
     public static class Constants
     {
         public static readonly TagDirective[] DefaultTagDirectives =
-        {
+        [
             new TagDirective("!", "!"),
             new TagDirective("!!", "tag:yaml.org,2002:")
-        };
+        ];
 
         public const int MajorVersion = 1;
         public const int MinorVersion = 3;

YamlDotNet/Core/Emitter.cs

@@ -56,7 +56,7 @@ public class Emitter : IEmitter
         private readonly Stack<EmitterState> states = new Stack<EmitterState>();
         private readonly Queue<ParsingEvent> events = new Queue<ParsingEvent>();
         private readonly Stack<int> indents = new Stack<int>();
-        private readonly TagDirectiveCollection tagDirectives = new TagDirectiveCollection();
+        private readonly TagDirectiveCollection tagDirectives = [];
         private int indent;
         private int flowLevel;
         private bool isMappingContext;

YamlDotNet/Core/MergingParser.cs

@@ -173,9 +173,9 @@ private sealed class ParsingEventCollection : IEnumerable<LinkedListNode<Parsing
 
             public ParsingEventCollection()
             {
-                events = new LinkedList<ParsingEvent>();
-                deleted = new HashSet<LinkedListNode<ParsingEvent>>();
-                references = new Dictionary<AnchorName, LinkedListNode<ParsingEvent>>();
+                events = [];
+                deleted = [];
+                references = [];
             }
 
             public void AddAfter(LinkedListNode<ParsingEvent> node, IEnumerable<ParsingEvent> items)

YamlDotNet/Core/Parser.cs

@@ -36,7 +36,7 @@ namespace YamlDotNet.Core
     public class Parser : IParser
     {
         private readonly Stack<ParserState> states = new Stack<ParserState>();
-        private readonly TagDirectiveCollection tagDirectives = new TagDirectiveCollection();
+        private readonly TagDirectiveCollection tagDirectives = [];
         private ParserState state;
 
         private readonly IScanner scanner;

YamlDotNet/Helpers/FsharpHelper.cs

@@ -73,7 +73,7 @@ public static bool IsFsharpListType(Type t)
                 .GetType("Microsoft.FSharp.Collections.ListModule")
                 .GetMethod("OfArray")
                 .MakeGenericMethod(itemsType)
-                .Invoke(null, new[] { arr });
+                .Invoke(null, [arr]);
 
             return fsharpList;
         }

YamlDotNet/Helpers/OrderedDictionary.cs

@@ -76,7 +76,7 @@ public OrderedDictionary() : this(EqualityComparer<TKey>.Default)
 
         public OrderedDictionary(IEqualityComparer<TKey> comparer)
         {
-            list = new List<KeyValuePair<TKey, TValue>>();
+            list = [];
             dictionary = new Dictionary<TKey, TValue>(comparer);
             this.comparer = comparer;
         }
@@ -192,7 +192,7 @@ public bool TryGetValue(TKey key, [MaybeNullWhen(false)] out TValue value) =>
         internal void OnDeserializedMethod(StreamingContext context)
         {
             // Reconstruct the dictionary from the serialized list
-            dictionary = new Dictionary<TKey, TValue>();
+            dictionary = [];
             foreach (var kvp in list)
             {
                 dictionary[kvp.Key] = kvp.Value;

YamlDotNet/RepresentationModel/DocumentLoadingState.cs

@@ -31,8 +31,8 @@ namespace YamlDotNet.RepresentationModel
     /// </summary>
     internal class DocumentLoadingState
     {
-        private readonly Dictionary<AnchorName, YamlNode> anchors = new Dictionary<AnchorName, YamlNode>();
-        private readonly List<YamlNode> nodesWithUnresolvedAliases = new List<YamlNode>();
+        private readonly Dictionary<AnchorName, YamlNode> anchors = [];
+        private readonly List<YamlNode> nodesWithUnresolvedAliases = [];
 
         /// <summary>
         /// Adds the specified node to the anchor list.

YamlDotNet/RepresentationModel/EmitterState.cs

@@ -33,6 +33,6 @@ internal class EmitterState
         /// Gets the already emitted anchors.
         /// </summary>
         /// <value>The emitted anchors.</value>
-        public HashSet<AnchorName> EmittedAnchors { get; } = new HashSet<AnchorName>();
+        public HashSet<AnchorName> EmittedAnchors { get; } = [];
     }
 }

YamlDotNet/RepresentationModel/YamlDocument.cs

@@ -90,11 +90,11 @@ internal YamlDocument(IParser parser)
         /// </summary>
         private class AnchorAssigningVisitor : YamlVisitorBase
         {
-            private readonly HashSet<AnchorName> existingAnchors = new HashSet<AnchorName>();
+            private readonly HashSet<AnchorName> existingAnchors = [];
             /// <summary>
             /// Key: Node, Value: IsDuplicate
             /// </summary>
-            private readonly Dictionary<YamlNode, bool> visitedNodes = new Dictionary<YamlNode, bool>();
+            private readonly Dictionary<YamlNode, bool> visitedNodes = [];
 
             public void AssignAnchors(YamlDocument document)
             {

YamlDotNet/RepresentationModel/YamlMappingNode.cs

@@ -36,7 +36,7 @@ namespace YamlDotNet.RepresentationModel
     /// </summary>
     public sealed class YamlMappingNode : YamlNode, IEnumerable<KeyValuePair<YamlNode, YamlNode>>, IYamlConvertible
     {
-        private readonly OrderedDictionary<YamlNode, YamlNode> children = new OrderedDictionary<YamlNode, YamlNode>();
+        private readonly OrderedDictionary<YamlNode, YamlNode> children = [];
 
         /// <summary>
         /// Gets the children of the current node.
@@ -196,13 +196,13 @@ internal override void ResolveAliases(DocumentLoadingState state)
             {
                 if (entry.Key is YamlAliasNode)
                 {
-                    keysToUpdate ??= new Dictionary<YamlNode, YamlNode>();
+                    keysToUpdate ??= [];
                     // TODO: The representation model should be redesigned, because here the anchor could be null but that would be invalid YAML
                     keysToUpdate.Add(entry.Key, state.GetNode(entry.Key.Anchor!, entry.Key.Start, entry.Key.End));
                 }
                 if (entry.Value is YamlAliasNode)
                 {
-                    valuesToUpdate ??= new Dictionary<YamlNode, YamlNode>();
+                    valuesToUpdate ??= [];
                     // TODO: The representation model should be redesigned, because here the anchor could be null but that would be invalid YAML
                     valuesToUpdate.Add(entry.Key, state.GetNode(entry.Value.Anchor!, entry.Value.Start, entry.Value.End));
                 }

YamlDotNet/RepresentationModel/YamlSequenceNode.cs

@@ -36,7 +36,7 @@ namespace YamlDotNet.RepresentationModel
     [DebuggerDisplay("Count = {children.Count}")]
     public sealed class YamlSequenceNode : YamlNode, IEnumerable<YamlNode>, IYamlConvertible
     {
-        private readonly List<YamlNode> children = new List<YamlNode>();
+        private readonly List<YamlNode> children = [];
 
         /// <summary>
         /// Gets the collection of child nodes.

YamlDotNet/Serialization/BufferedDeserialization/TypeDiscriminatingNodeDeserializerOptions.cs

@@ -30,7 +30,7 @@ namespace YamlDotNet.Serialization.BufferedDeserialization
 {
     public class TypeDiscriminatingNodeDeserializerOptions : ITypeDiscriminatingNodeDeserializerOptions
     {
-        internal readonly List<ITypeDiscriminator> discriminators = new List<ITypeDiscriminator>();
+        internal readonly List<ITypeDiscriminator> discriminators = [];
 
         /// <summary>
         /// Adds an <see cref="ITypeDiscriminator" /> to be checked by the TypeDiscriminatingNodeDeserializer.
@@ -64,4 +64,4 @@ public void AddUniqueKeyTypeDiscriminator<T>(IDictionary<string, Type> uniqueKey
             this.discriminators.Add(new UniqueKeyTypeDiscriminator(typeof(T), uniqueKeyTypeMapping));
         }
     }
-}
+}

YamlDotNet/Serialization/BuilderSkeleton.cs

@@ -58,7 +58,7 @@ internal BuilderSkeleton(ITypeResolver typeResolver)
                 { typeof(SystemTypeConverter), _ => new SystemTypeConverter() }
             };
 
-            typeInspectorFactories = new LazyComponentRegistrationList<ITypeInspector, ITypeInspector>();
+            typeInspectorFactories = [];
             this.typeResolver = typeResolver ?? throw new ArgumentNullException(nameof(typeResolver));
             settings = new Settings();
         }

YamlDotNet/Serialization/DeserializerBuilder.cs

@@ -71,7 +71,7 @@ public sealed class DeserializerBuilder : BuilderSkeleton<DeserializerBuilder>
         public DeserializerBuilder()
             : base(new StaticTypeResolver())
         {
-            typeMappings = new Dictionary<Type, Type>();
+            typeMappings = [];
             objectFactory = new Lazy<IObjectFactory>(() => new DefaultObjectFactory(typeMappings, settings), true);
 
             tagMappings = new Dictionary<TagName, Type>

YamlDotNet/Serialization/LazyComponentRegistrationList.cs

@@ -28,7 +28,7 @@ namespace YamlDotNet.Serialization
 {
     internal sealed class LazyComponentRegistrationList<TArgument, TComponent> : IEnumerable<Func<TArgument, TComponent>>
     {
-        private readonly List<LazyComponentRegistration> entries = new List<LazyComponentRegistration>();
+        private readonly List<LazyComponentRegistration> entries = [];
 
         public LazyComponentRegistrationList<TArgument, TComponent> Clone()
         {

YamlDotNet/Serialization/ObjectGraphVisitors/AnchorAssigner.cs

@@ -33,7 +33,7 @@ private class AnchorAssignment
             public AnchorName Anchor;
         }
 
-        private readonly Dictionary<object, AnchorAssignment> assignments = new Dictionary<object, AnchorAssignment>();
+        private readonly Dictionary<object, AnchorAssignment> assignments = [];
         private uint nextId;
 
         public AnchorAssigner(IEnumerable<IYamlTypeConverter> typeConverters)

YamlDotNet/Serialization/ObjectGraphVisitors/AnchorAssigningObjectGraphVisitor.cs

@@ -29,7 +29,7 @@ public sealed class AnchorAssigningObjectGraphVisitor : ChainedObjectGraphVisito
     {
         private readonly IEventEmitter eventEmitter;
         private readonly IAliasProvider aliasProvider;
-        private readonly HashSet<AnchorName> emittedAliases = new HashSet<AnchorName>();
+        private readonly HashSet<AnchorName> emittedAliases = [];
 
         public AnchorAssigningObjectGraphVisitor(IObjectGraphVisitor<IEmitter> nextVisitor, IEventEmitter eventEmitter, IAliasProvider aliasProvider)
             : base(nextVisitor)

YamlDotNet/Serialization/SerializerBuilder.cs

@@ -55,7 +55,7 @@ public sealed class SerializerBuilder : BuilderSkeleton<SerializerBuilder>
         private readonly LazyComponentRegistrationList<IEnumerable<IYamlTypeConverter>, IObjectGraphVisitor<Nothing>> preProcessingPhaseObjectGraphVisitorFactories;
         private readonly LazyComponentRegistrationList<EmissionPhaseObjectGraphVisitorArgs, IObjectGraphVisitor<IEmitter>> emissionPhaseObjectGraphVisitorFactories;
         private readonly LazyComponentRegistrationList<IEventEmitter, IEventEmitter> eventEmitterFactories;
-        private readonly Dictionary<Type, TagName> tagMappings = new Dictionary<Type, TagName>();
+        private readonly Dictionary<Type, TagName> tagMappings = [];
         private readonly IObjectFactory objectFactory;
         private int maximumRecursion = 50;
         private EmitterSettings emitterSettings = EmitterSettings.Default;

YamlDotNet/Serialization/StaticBuilderSkeleton.cs

@@ -50,7 +50,7 @@ internal StaticBuilderSkeleton(ITypeResolver typeResolver)
                 { typeof(GuidConverter), _ => new GuidConverter(false) },
             };
 
-            typeInspectorFactories = new LazyComponentRegistrationList<ITypeInspector, ITypeInspector>();
+            typeInspectorFactories = [];
             this.typeResolver = typeResolver ?? throw new ArgumentNullException(nameof(typeResolver));
             settings = new Settings();
         }

YamlDotNet/Serialization/StaticDeserializerBuilder.cs

@@ -69,7 +69,7 @@ public StaticDeserializerBuilder(StaticContext context)
         {
             this.context = context;
             factory = context.GetFactory();
-            typeMappings = new Dictionary<Type, Type>();
+            typeMappings = [];
 
             tagMappings = new Dictionary<TagName, Type>
             {

YamlDotNet/Serialization/StaticSerializerBuilder.cs

@@ -52,7 +52,7 @@ public sealed class StaticSerializerBuilder : StaticBuilderSkeleton<StaticSerial
         private readonly LazyComponentRegistrationList<IEnumerable<IYamlTypeConverter>, IObjectGraphVisitor<Nothing>> preProcessingPhaseObjectGraphVisitorFactories;
         private readonly LazyComponentRegistrationList<EmissionPhaseObjectGraphVisitorArgs, IObjectGraphVisitor<IEmitter>> emissionPhaseObjectGraphVisitorFactories;
         private readonly LazyComponentRegistrationList<IEventEmitter, IEventEmitter> eventEmitterFactories;
-        private readonly Dictionary<Type, TagName> tagMappings = new Dictionary<Type, TagName>();
+        private readonly Dictionary<Type, TagName> tagMappings = [];
         private int maximumRecursion = 50;
         private EmitterSettings emitterSettings = EmitterSettings.Default;
         private DefaultValuesHandling defaultValuesHandlingConfiguration = DefaultValuesHandling.Preserve;

YamlDotNet/Serialization/StreamFragment.cs

@@ -32,7 +32,7 @@ namespace YamlDotNet.Serialization
     /// </summary>
     public sealed class StreamFragment : IYamlConvertible
     {
-        private readonly List<ParsingEvent> events = new List<ParsingEvent>();
+        private readonly List<ParsingEvent> events = [];
 
         /// <summary>
         /// Gets or sets the events.

YamlDotNet/Serialization/TagMappings.cs

@@ -36,7 +36,7 @@ public sealed class TagMappings
         /// </summary>
         public TagMappings()
         {
-            mappings = new Dictionary<string, Type>();
+            mappings = [];
         }
 
         /// <summary>

YamlDotNet/Serialization/Utilities/ObjectAnchorCollection.cs

@@ -27,8 +27,8 @@ namespace YamlDotNet.Serialization.Utilities
 {
     internal sealed class ObjectAnchorCollection
     {
-        private readonly Dictionary<string, object> objectsByAnchor = new Dictionary<string, object>();
-        private readonly Dictionary<object, string> anchorsByObject = new Dictionary<object, string>();
+        private readonly Dictionary<string, object> objectsByAnchor = [];
+        private readonly Dictionary<object, string> anchorsByObject = [];
 
         /// <summary>
         /// Adds the specified anchor.

YamlDotNet/Serialization/Utilities/SerializerState.cs

@@ -31,7 +31,7 @@ namespace YamlDotNet.Serialization.Utilities
     /// </summary>
     public sealed class SerializerState : IDisposable
     {
-        private readonly Dictionary<Type, object> items = new Dictionary<Type, object>();
+        private readonly Dictionary<Type, object> items = [];
 
         public T Get<T>()
             where T : class, new()

YamlDotNet/Serialization/Utilities/TypeConverter.cs

@@ -180,7 +180,7 @@ public static T ChangeType<T>(object? value, INamingConvention enumNamingConvent
                         {
                             try
                             {
-                                return method.Invoke(null, new[] { value });
+                                return method.Invoke(null, [value]);
                             }
                             catch (TargetInvocationException ex)
                             {
@@ -200,14 +200,14 @@ public static T ChangeType<T>(object? value, INamingConvention enumNamingConvent
                     var parseMethod = destinationType.GetPublicStaticMethod("Parse", typeof(string), typeof(IFormatProvider));
                     if (parseMethod != null)
                     {
-                        return parseMethod.Invoke(null, new object[] { value, culture });
+                        return parseMethod.Invoke(null, [value, culture]);
                     }
 
                     // Try with - public static T Parse(string)
                     parseMethod = destinationType.GetPublicStaticMethod("Parse", typeof(string));
                     if (parseMethod != null)
                     {
-                        return parseMethod.Invoke(null, new object[] { value });
+                        return parseMethod.Invoke(null, [value]);
                     }
                 }
                 catch (TargetInvocationException ex)

YamlDotNet/Serialization/YamlAttributeOverrides.cs

@@ -108,7 +108,7 @@ public int Matches(Type matchType)
             }
         }
 
-        private readonly Dictionary<AttributeKey, List<AttributeMapping>> overrides = new Dictionary<AttributeKey, List<AttributeMapping>>();
+        private readonly Dictionary<AttributeKey, List<AttributeMapping>> overrides = [];
 
         [return: MaybeNull]
         public T GetAttribute<T>(Type type, string member) where T : Attribute
@@ -150,7 +150,7 @@ public void Add(Type type, string member, Attribute attribute)
             var attributeKey = new AttributeKey(attribute.GetType(), member);
             if (!overrides.TryGetValue(attributeKey, out var mappings))
             {
-                mappings = new List<AttributeMapping>();
+                mappings = [];
                 overrides.Add(attributeKey, mappings);
             }
             else if (mappings.Contains(mapping))

YamlDotNet/Serialization/YamlFormatter.cs

@@ -32,12 +32,12 @@ public class YamlFormatter
         {
             CurrencyDecimalSeparator = ".",
             CurrencyGroupSeparator = "_",
-            CurrencyGroupSizes = new[] { 3 },
+            CurrencyGroupSizes = [3],
             CurrencySymbol = string.Empty,
             CurrencyDecimalDigits = 99,
             NumberDecimalSeparator = ".",
             NumberGroupSeparator = "_",
-            NumberGroupSizes = new[] { 3 },
+            NumberGroupSizes = [3],
             NumberDecimalDigits = 99,
             NaNSymbol = ".nan",
             PositiveInfinitySymbol = ".inf",

YamlDotNet/YamlDotNet.csproj

@@ -61,17 +61,14 @@
     <NoWarn>$(NoWarn);CA1725</NoWarn>  <!-- Parameter names should match base declaration and other partial definitions -->
     <NoWarn>$(NoWarn);CS1061;CA1016</NoWarn>  <!-- Mark assemblies with assembly version -->
 
-    <NoWarn>$(NoWarn);IDE0028</NoWarn>  <!-- Collection initialization can be simplified  -->
     <NoWarn>$(NoWarn);IDE0045</NoWarn>  <!-- 'if' statement can be simplified -->
     <NoWarn>$(NoWarn);IDE0046</NoWarn>  <!-- 'if' statement can be simplified -->
     <NoWarn>$(NoWarn);IDE0047</NoWarn>  <!-- Parentheses can be removed -->
     <NoWarn>$(NoWarn);IDE0078</NoWarn>  <!-- Use pattern matching  -->
     <NoWarn>$(NoWarn);IDE0083</NoWarn>  <!-- Use pattern matching  -->
     <NoWarn>$(NoWarn);IDE0090</NoWarn>  <!-- 'new' expression can be simplified  -->
     <NoWarn>$(NoWarn);IDE0110</NoWarn>  <!-- Discard can be removed  -->
-    <NoWarn>$(NoWarn);IDE0251</NoWarn>  <!-- Member can be made 'readonly' -->
     <NoWarn>$(NoWarn);IDE0290</NoWarn>  <!-- Use primary constructor -->
-    <NoWarn>$(NoWarn);IDE0300</NoWarn>  <!-- Collection initialization can be simplified  -->
   </PropertyGroup>
 
 </Project>