Fix multipart form-data parameter extraction

.refitter

@@ -0,0 +1,88 @@
+{
+  "openApiPath": "./test-anytype.json",
+  "openApiPaths": [],
+  "namespace": "TestNS",
+  "contractsNamespace": null,
+  "naming": {
+    "useOpenApiTitle": true,
+    "interfaceName": "ApiClient"
+  },
+  "generateContracts": true,
+  "generateClients": true,
+  "generateDisposableClients": false,
+  "generateXmlDocCodeComments": true,
+  "generateStatusCodeComments": true,
+  "addAutoGeneratedHeader": true,
+  "addAcceptHeaders": true,
+  "addContentTypeHeaders": true,
+  "returnIApiResponse": false,
+  "returnIObservable": false,
+  "responseTypeOverride": {},
+  "generateOperationHeaders": true,
+  "ignoredOperationHeaders": [],
+  "typeAccessibility": "Public",
+  "useCancellationTokens": false,
+  "useIsoDateFormat": false,
+  "additionalNamespaces": [],
+  "excludeNamespaces": [],
+  "multipleInterfaces": "Unset",
+  "includePathMatches": [],
+  "includeTags": [],
+  "generateDeprecatedOperations": true,
+  "operationNameTemplate": null,
+  "optionalParameters": false,
+  "outputFolder": "./Generated",
+  "contractsOutputFolder": "./test-output.cs",
+  "outputFilename": null,
+  "dependencyInjectionSettings": null,
+  "codeGeneratorSettings": {
+    "requiredPropertiesMustBeDefined": true,
+    "generateDataAnnotations": true,
+    "anyType": "object",
+    "dateType": "System.DateTimeOffset",
+    "dateTimeType": "System.DateTimeOffset",
+    "timeType": "System.TimeSpan",
+    "timeSpanType": "System.TimeSpan",
+    "integerType": "Int32",
+    "arrayType": "System.Collections.Generic.ICollection",
+    "dictionaryType": "System.Collections.Generic.IDictionary",
+    "arrayInstanceType": "System.Collections.ObjectModel.Collection",
+    "dictionaryInstanceType": "System.Collections.Generic.Dictionary",
+    "arrayBaseType": "System.Collections.ObjectModel.Collection",
+    "dictionaryBaseType": "System.Collections.Generic.Dictionary",
+    "propertySetterAccessModifier": "",
+    "jsonConverters": null,
+    "generateImmutableArrayProperties": false,
+    "generateImmutableDictionaryProperties": false,
+    "handleReferences": false,
+    "jsonSerializerSettingsTransformationMethod": null,
+    "generateJsonMethods": false,
+    "enforceFlagEnums": false,
+    "inlineNamedDictionaries": false,
+    "inlineNamedTuples": true,
+    "inlineNamedArrays": false,
+    "generateOptionalPropertiesAsNullable": false,
+    "generateNullableReferenceTypes": false,
+    "generateNativeRecords": false,
+    "generateDefaultValues": true,
+    "inlineNamedAny": false,
+    "excludedTypeNames": [],
+    "dateFormat": null,
+    "dateTimeFormat": null,
+    "inlineJsonConverters": true,
+    "customTemplateDirectory": null
+  },
+  "trimUnusedSchema": false,
+  "keepSchemaPatterns": [],
+  "includeInheritanceHierarchy": false,
+  "operationNameGenerator": "Default",
+  "generateDefaultAdditionalProperties": true,
+  "immutableRecords": false,
+  "apizrSettings": null,
+  "useDynamicQuerystringParameters": false,
+  "generateMultipleFiles": false,
+  "usePolymorphicSerialization": false,
+  "generateAuthenticationHeader": false,
+  "collectionFormat": "Multi",
+  "customTemplateDirectory": null
+}

docs/format-mappings-example.json

@@ -0,0 +1,6 @@
+{
+  "int32": "int",
+  "int64": "ulong",
+  "float": "float",
+  "double": "double"
+}

docs/format-mappings-schema.json

@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "Refitter Format Mappings",
+  "description": "Custom format-to-type mappings for OpenAPI schema formats. Use this to override the default C# type mappings for specific OpenAPI formats.",
+  "type": "object",
+  "additionalProperties": {
+    "type": "string",
+    "description": "The .NET type name to use for this format"
+  },
+  "examples": [
+    {
+      "int32": "int",
+      "int64": "ulong",
+      "float": "float",
+      "double": "double",
+      "byte": "byte",
+      "binary": "byte[]",
+      "date": "System.DateTime",
+      "date-time": "System.DateTime",
+      "password": "string",
+      "uuid": "System.Guid"
+    }
+  ]
+}

src/Refitter.Core/ContractTypeSuffixApplier.cs

@@ -0,0 +1,57 @@
+using System.Text.RegularExpressions;
+
+namespace Refitter.Core;
+
+internal static class ContractTypeSuffixApplier
+{
+    private static readonly Regex TypeDeclarationRegex =
+        new(@"(?:public|internal)\s+(?:partial\s+)?(?:class|record|struct|interface)\s+(\w+)", RegexOptions.Multiline | RegexOptions.Compiled);
+
+    private static readonly Regex EnumDeclarationRegex =
+        new(@"(?:public|internal)\s+(?:partial\s+)?enum\s+(\w+)", RegexOptions.Multiline | RegexOptions.Compiled);
+
+    public static string ApplySuffix(string generatedCode, string suffix)
+    {
+        if (string.IsNullOrWhiteSpace(suffix))
+            return generatedCode;
+
+        var typeNames = new HashSet<string>();
+
+        // First pass: collect all type names (classes, records, structs, enums)
+        foreach (Match match in TypeDeclarationRegex.Matches(generatedCode))
+        {
+            typeNames.Add(match.Groups[1].Value);
+        }
+
+        foreach (Match match in EnumDeclarationRegex.Matches(generatedCode))
+        {
+            typeNames.Add(match.Groups[1].Value);
+        }
+
+        // Second pass: replace type names with suffixed versions
+        // Sort by length (longest first) to avoid partial replacements
+        var orderedTypeNames = typeNames.OrderByDescending(t => t.Length).ToList();
+        var result = generatedCode;
+
+        foreach (var typeName in orderedTypeNames)
+        {
+            var suffixedName = typeName + suffix;
+
+            // Replace type declarations
+            result = Regex.Replace(
+                result,
+                $@"(?:public|internal)\s+((?:partial\s+)?(?:class|record|struct|enum))\s+\b{Regex.Escape(typeName)}\b",
+                m => $"{m.Groups[0].Value.Replace(typeName, suffixedName)}",
+                RegexOptions.Multiline);
+
+            // Replace type references in inheritance, properties, parameters, etc.
+            // Match word boundaries to avoid partial replacements
+            result = Regex.Replace(
+                result,
+                $@"\b{Regex.Escape(typeName)}\b(?![a-zA-Z0-9_])",
+                suffixedName);
+        }
+
+        return result;
+    }
+}

src/Refitter.Core/CustomCSharpTypeResolver.cs

@@ -0,0 +1,38 @@
+using NJsonSchema;
+using NJsonSchema.CodeGeneration;
+using NJsonSchema.CodeGeneration.CSharp;
+
+namespace Refitter.Core;
+
+internal class CustomCSharpTypeResolver : CSharpTypeResolver
+{
+    private readonly Dictionary<string, string>? formatMappings;
+
+    public CustomCSharpTypeResolver(
+        CSharpGeneratorSettings settings,
+        Dictionary<string, string>? formatMappings)
+        : base(settings)
+    {
+        this.formatMappings = formatMappings;
+    }
+
+    public override string Resolve(
+        JsonSchema schema,
+        bool isNullable,
+        string? typeNameHint)
+    {
+        // Check if this schema has a format with a custom mapping
+        if (formatMappings != null &&
+            !string.IsNullOrEmpty(schema.Format) &&
+            formatMappings.TryGetValue(schema.Format, out var mappedType))
+        {
+            // Return the custom mapped type with nullability
+            return isNullable && !mappedType.EndsWith("?") && !mappedType.Contains("<")
+                ? $"{mappedType}?"
+                : mappedType;
+        }
+
+        // Fall back to default NSwag type resolution
+        return base.Resolve(schema, isNullable, typeNameHint);
+    }
+}

src/Refitter.Core/JsonSerializerContextGenerator.cs

@@ -0,0 +1,75 @@
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace Refitter.Core;
+
+/// <summary>
+/// Generates JsonSerializerContext for AOT compilation support
+/// </summary>
+internal static class JsonSerializerContextGenerator
+{
+    /// <summary>
+    /// Generates a JsonSerializerContext class with all DTO types registered for source generation
+    /// </summary>
+    /// <param name="contracts">The generated contracts code containing the DTO types</param>
+    /// <param name="settings">The generator settings</param>
+    /// <returns>The generated JsonSerializerContext code</returns>
+    public static string Generate(string contracts, RefitGeneratorSettings settings)
+    {
+        var typeNames = ExtractTypeNames(contracts);
+        if (typeNames.Count == 0)
+            return string.Empty;
+
+        var contextName = $"{settings.Naming.InterfaceName}SerializerContext";
+        var sb = new StringBuilder();
+
+        // Add all JsonSerializable attributes
+        foreach (var typeName in typeNames.OrderBy(t => t))
+        {
+            sb.AppendLine($"[JsonSerializable(typeof({typeName}))]");
+        }
+
+        // Add context class
+        sb.AppendLine($"internal partial class {contextName} : JsonSerializerContext");
+        sb.AppendLine("{");
+        sb.AppendLine("}");
+
+        return sb.ToString();
+    }
+
+    /// <summary>
+    /// Extracts type names (classes, records, enums) from generated contracts
+    /// </summary>
+    private static HashSet<string> ExtractTypeNames(string contracts)
+    {
+        var typeNames = new HashSet<string>();
+
+        // Match class declarations: public class TypeName, internal class TypeName
+        var classPattern = new Regex(
+            @"^\s*(?:public|internal)\s+(?:partial\s+)?(?:class|record)\s+([A-Za-z_][A-Za-z0-9_]*)",
+            RegexOptions.Multiline);
+
+        foreach (Match match in classPattern.Matches(contracts))
+        {
+            if (match.Success && match.Groups.Count > 1)
+            {
+                typeNames.Add(match.Groups[1].Value);
+            }
+        }
+
+        // Match enum declarations: public enum TypeName, internal enum TypeName
+        var enumPattern = new Regex(
+            @"^\s*(?:public|internal)\s+enum\s+([A-Za-z_][A-Za-z0-9_]*)",
+            RegexOptions.Multiline);
+
+        foreach (Match match in enumPattern.Matches(contracts))
+        {
+            if (match.Success && match.Groups.Count > 1)
+            {
+                typeNames.Add(match.Groups[1].Value);
+            }
+        }
+
+        return typeNames;
+    }
+}