Default headers should allow multiple values

Author: alexeyzimarev

gen/SourceGenerator/ImmutableGenerator.cs

@@ -32,22 +32,24 @@ public void Execute(GeneratorExecutionContext context) {
 
     static string GenerateImmutableClass(TypeDeclarationSyntax mutableClass, Compilation compilation) {
         var containingNamespace = compilation.GetSemanticModel(mutableClass.SyntaxTree).GetDeclaredSymbol(mutableClass)!.ContainingNamespace;
-
-        var namespaceName = containingNamespace.ToDisplayString();
-
-        var className = mutableClass.Identifier.Text;
-
-        var usings = mutableClass.SyntaxTree.GetCompilationUnitRoot().Usings.Select(u => u.ToString());
+        var namespaceName       = containingNamespace.ToDisplayString();
+        var className           = mutableClass.Identifier.Text;
+        var usings              = mutableClass.SyntaxTree.GetCompilationUnitRoot().Usings.Select(u => u.ToString());
 
         var properties = GetDefinitions(SyntaxKind.SetKeyword)
-            .Select(prop => $"    public {prop.Type} {prop.Identifier.Text} {{ get; }}")
+            .Select(
+                prop => {
+                    var xml = prop.GetLeadingTrivia().FirstOrDefault(x => x.IsKind(SyntaxKind.SingleLineDocumentationCommentTrivia)).GetStructure();
+                    return $"/// {xml}    public {prop.Type} {prop.Identifier.Text} {{ get; }}";
+                }
+            )
             .ToArray();
 
         var props = GetDefinitions(SyntaxKind.SetKeyword).ToArray();
 
         const string argName = "inner";
-        var mutableProperties = props
-            .Select(prop => $"        {prop.Identifier.Text} = {argName}.{prop.Identifier.Text};");
+
+        var mutableProperties = props.Select(prop => $"        {prop.Identifier.Text} = {argName}.{prop.Identifier.Text};");
 
         var constructor = $$"""
                                 public ReadOnly{{className}}({{className}} {{argName}}) {
@@ -85,7 +87,8 @@ IEnumerable<PropertyDeclarationSyntax> GetDefinitions(SyntaxKind kind)
                 .OfType<PropertyDeclarationSyntax>()
                 .Where(
                     prop =>
-                        prop.AccessorList!.Accessors.Any(accessor => accessor.Keyword.IsKind(kind)) && prop.AttributeLists.All(list => list.Attributes.All(attr => attr.Name.ToString() != "Exclude"))
+                        prop.AccessorList!.Accessors.Any(accessor => accessor.Keyword.IsKind(kind)) &&
+                        prop.AttributeLists.All(list => list.Attributes.All(attr => attr.Name.ToString() != "Exclude"))
                 );
     }
-}
+}

src/RestSharp/Options/RestClientOptions.cs

@@ -210,6 +210,7 @@ public RestClientOptions(string baseUrl) : this(new Uri(Ensure.NotEmptyString(ba
 
     /// <summary>
     /// Set to true to allow multiple default parameters with the same name. Default is false.
+    /// This setting doesn't apply to headers as multiple header values for the same key is allowed.
     /// </summary>
     public bool AllowMultipleDefaultParametersWithSameName { get; set; }
 

src/RestSharp/Parameters/DefaultParameters.cs

@@ -28,9 +28,7 @@ public sealed class DefaultParameters(ReadOnlyRestClientOptions options) : Param
     [MethodImpl(MethodImplOptions.Synchronized)]
     public DefaultParameters AddParameter(Parameter parameter) {
         if (parameter.Type == ParameterType.RequestBody)
-            throw new NotSupportedException(
-                "Cannot set request body using default parameters. Use Request.AddBody() instead."
-            );
+            throw new NotSupportedException("Cannot set request body using default parameters. Use Request.AddBody() instead.");
 
         if (!options.AllowMultipleDefaultParametersWithSameName &&
             parameter.Type != ParameterType.HttpHeader &&

src/RestSharp/Parameters/Parameter.cs

@@ -44,14 +44,16 @@ protected Parameter(string? name, object? value, ParameterType type, bool encode
     /// Return a human-readable representation of this parameter
     /// </summary>
     /// <returns>String</returns>
-    public sealed override string ToString() => Value == null ? $"{Name}" : $"{Name}={Value}";
+    public sealed override string ToString() => Value == null ? $"{Name}" : $"{Name}={ValueString}";
+
+    protected virtual string ValueString => Value?.ToString() ?? "null";
 
     public static Parameter CreateParameter(string? name, object? value, ParameterType type, bool encode = true)
         // ReSharper disable once SwitchExpressionHandlesSomeKnownEnumValuesWithExceptionInDefault
         => type switch {
             ParameterType.GetOrPost   => new GetOrPostParameter(Ensure.NotEmptyString(name, nameof(name)), value?.ToString(), encode),
             ParameterType.UrlSegment  => new UrlSegmentParameter(Ensure.NotEmptyString(name, nameof(name)), value?.ToString()!, encode),
-            ParameterType.HttpHeader  => new HeaderParameter(name, value?.ToString()),
+            ParameterType.HttpHeader  => new HeaderParameter(name!, value?.ToString()!),
             ParameterType.QueryString => new QueryParameter(Ensure.NotEmptyString(name, nameof(name)), value?.ToString(), encode),
             _                         => throw new ArgumentOutOfRangeException(nameof(type), type, null)
         };

src/RestSharp/Request/RestRequest.cs

@@ -16,8 +16,8 @@
 using RestSharp.Authenticators;
 using RestSharp.Extensions;
 using RestSharp.Interceptors;
-// ReSharper disable AutoPropertyCanBeMadeGetOnly.Global
 
+// ReSharper disable AutoPropertyCanBeMadeGetOnly.Global
 // ReSharper disable UnusedAutoPropertyAccessor.Global
 
 namespace RestSharp;

src/RestSharp/Request/RestRequestExtensions.Headers.cs

@@ -17,6 +17,21 @@
 namespace RestSharp;
 
 public static partial class RestRequestExtensions {
+    /// <summary>
+    /// Adds a header to the request. RestSharp will try to separate request and content headers when calling the resource.
+    /// </summary>
+    /// <param name="request">Request instance</param>
+    /// <param name="name">Header name</param>
+    /// <param name="values">Header values</param>
+    /// <returns></returns>
+    public static RestRequest AddHeader(this RestRequest request, string name, string[] values) {
+        foreach (var value in values) {
+            AddHeader(request, name, value);
+        }
+
+        return request;
+    }
+
     /// <summary>
     /// Adds a header to the request. RestSharp will try to separate request and content headers when calling the resource.
     /// </summary>
@@ -41,7 +56,7 @@ public static RestRequest AddHeader<T>(this RestRequest request, string name, T
 
     /// <summary>
     /// Adds or updates the request header. RestSharp will try to separate request and content headers when calling the resource.
-    /// Existing header with the same name will be replaced.
+    /// The existing header with the same name will be replaced.
     /// </summary>
     /// <param name="request">Request instance</param>
     /// <param name="name">Header name</param>
@@ -54,7 +69,7 @@ public static RestRequest AddOrUpdateHeader(this RestRequest request, string nam
 
     /// <summary>
     /// Adds or updates the request header. RestSharp will try to separate request and content headers when calling the resource.
-    /// Existing header with the same name will be replaced.
+    /// The existing header with the same name will be replaced.
     /// </summary>
     /// <param name="request">Request instance</param>
     /// <param name="name">Header name</param>

test/RestSharp.Tests/RequestHeaderTests.cs

@@ -63,7 +63,6 @@ public void AddOrUpdateHeader_ShouldUpdateExistingHeader_WhenHeaderExist() {
         request.AddOrUpdateHeader(KnownHeaders.Accept, ContentType.Json);
 
         // Assert
-        var headers = GetHeaders(request);
         GetHeader(request, KnownHeaders.Accept).Should().Be(ContentType.Json);
     }
 
@@ -158,16 +157,18 @@ public void AddOrUpdateHeaders_ShouldAddAndUpdateHeaders_WhenSomeExists() {
 
     [Fact]
     public void Should_not_allow_null_header_value() {
-        var request = new RestRequest();
-        Assert.Throws<ArgumentNullException>("value", () => request.AddHeader("name", null!));
+        string value   = null;
+        var    request = new RestRequest();
+        // ReSharper disable once AssignNullToNotNullAttribute
+        Assert.Throws<ArgumentNullException>("value", () => request.AddHeader("name", value));
     }
-    
+
     [Fact]
     public void Should_not_allow_null_header_name() {
         var request = new RestRequest();
         Assert.Throws<ArgumentNullException>("name", () => request.AddHeader(null!, "value"));
     }
-    
+
     [Fact]
     public void Should_not_allow_empty_header_name() {
         var request = new RestRequest();