Fix .NET SDK serialization bugs in SubFormFieldRuleAction.TypeEnum and optional int request fields

sdks/dotnet/bin/copy-constants.php

@@ -13,17 +13,26 @@
 });
 
 /**
- * Between openapi-generator v7.8.0 and v7.12.0 a change was made to the way
- * a few generators create constant names from values. The original way was
- * actually broken. For example "change-field-visibility" would generate a
- * constant name of "TYPE_FIELD_VISIBILITY", dropping the "change" part.
+ * Post-generation patch for SubFormFieldRuleAction.cs.
  *
- * The fix now generates the correct name, "TYPE_CHANGE_FIELD_VISIBILITY".
- * However, the fix also gets rid of the previous (incorrect) constant names,
- * making the fix a BC break.
+ * Between openapi-generator v7.8.0 and v7.12.0 a change was made to the
+ * way a few generators create constant names from values. The original
+ * way was broken: "change-field-visibility" generated a constant named
+ * "TYPE_FIELD_VISIBILITY", dropping the "change" part. The fix generates
+ * the correct name, "TYPE_CHANGE_FIELD_VISIBILITY", but also removes the
+ * previous (incorrect) names, which is a BC break.
  *
- * This simple script just adds the old constant names back, alongside the new
- * ones.
+ * To preserve source compatibility this script adds the old names back
+ * as aliases (FieldVisibility = ChangeFieldVisibility, etc.). The aliases
+ * share a numeric value with their canonical counterparts, which breaks
+ * StringEnumConverter: Enum.GetName is not guaranteed to pick the
+ * canonical name for ties, and Newtonsoft rejects duplicate
+ * [EnumMember] values on the same enum. To make the aliases serialize
+ * to the correct OpenAPI wire values under all circumstances, this
+ * script also:
+ *   - swaps StringEnumConverter for a dedicated TypeEnumJsonConverter
+ *     that maps by underlying numeric value, and
+ *   - injects that nested converter class into SubFormFieldRuleAction.
  */
 class CopyConstants
 {
@@ -32,6 +41,57 @@ public function run(): void
         $file = __DIR__ . '/../src/Dropbox.Sign/Model/SubFormFieldRuleAction.cs';
         $contents = file_get_contents($file);
 
+        $contents = $this->addAliases($contents);
+        $contents = $this->swapConverter($contents);
+        $contents = $this->injectConverterClass($contents);
+
+        file_put_contents($file, $contents);
+
+        $this->stopEmittingDefaultIntValues(__DIR__ . '/../src/Dropbox.Sign/Model');
+    }
+
+    /**
+     * For optional non-nullable int properties on request-side models
+     * openapi-generator emits
+     *   [DataMember(Name = "foo", EmitDefaultValue = true)]
+     *   public int Foo { get; set; }
+     * which forces `"foo": 0` onto the wire whenever the caller never
+     * set a value (C# default for int is 0). For fields like font_size
+     * the server rejects the default with a 400 ("'font_size' must be
+     * between 7 and 49"), and more generally any optional int whose
+     * server-side default is not 0 is misrepresented.
+     *
+     * Scope:
+     *   - Only request-side models are patched. Response models keep
+     *     EmitDefaultValue = true so that round-trip serialization
+     *     preserves explicit zero values that the server sent (tests
+     *     under Dropbox.Sign.Test.Api rely on this fidelity). Response
+     *     models are identified by the "Response" substring in the
+     *     file name, which is the convention for all generated
+     *     response types in this SDK.
+     *   - Required int properties are left alone: openapi-generator
+     *     inserts `IsRequired = true,` between the Name and
+     *     EmitDefaultValue tokens, which this regex does not match.
+     */
+    private function stopEmittingDefaultIntValues(string $modelDir): void
+    {
+        $pattern = '/(\[DataMember\(Name = "[^"]+", EmitDefaultValue = )true(\)\]\s*\r?\n\s+public int [A-Za-z_][A-Za-z0-9_]* \{ get; set; \})/';
+
+        foreach (glob($modelDir . '/*.cs') as $path) {
+            if (strpos(basename($path), 'Response') !== false) {
+                continue;
+            }
+
+            $contents = file_get_contents($path);
+            $patched  = preg_replace($pattern, '$1false$2', $contents);
+            if ($patched !== null && $patched !== $contents) {
+                file_put_contents($path, $patched);
+            }
+        }
+    }
+
+    private function addAliases(string $contents): string
+    {
         $constant_1 = "            ChangeFieldVisibility = 1,";
         $replace_1 = implode("\n", [
             $constant_1,
@@ -44,21 +104,99 @@ public function run(): void
             '            GroupVisibility = ChangeGroupVisibility',
         ]);
 
-        $contents = str_replace(
-            $constant_1,
-            $replace_1,
-            $contents,
-        );
+        $contents = str_replace($constant_1, $replace_1, $contents);
+        $contents = str_replace($constant_2, $replace_2, $contents);
 
-        $contents = str_replace(
-            $constant_2,
-            $replace_2,
-            $contents,
-        );
+        return $contents;
+    }
 
-        file_put_contents($file, $contents);
+    private function swapConverter(string $contents): string
+    {
+        $needle = "        [JsonConverter(typeof(StringEnumConverter))]\n"
+                . "        public enum TypeEnum";
+
+        $replacement = <<<'CS'
+        // A dedicated converter is used instead of StringEnumConverter
+        // because this enum intentionally carries alias members
+        // (FieldVisibility, GroupVisibility) that share a numeric value
+        // with their canonical counterparts. StringEnumConverter goes
+        // through Enum.GetName, which is not guaranteed to pick the
+        // canonical name when multiple members share a value, and
+        // Newtonsoft rejects duplicate [EnumMember] values on the same
+        // enum. Mapping by numeric value here is unambiguous: both the
+        // canonical name and its alias produce the same wire string.
+        [JsonConverter(typeof(TypeEnumJsonConverter))]
+        public enum TypeEnum
+CS;
+
+        return str_replace($needle, $replacement, $contents);
+    }
+
+    private function injectConverterClass(string $contents): string
+    {
+        // Inject the nested converter immediately after the enum's
+        // closing brace. Anchor on the enum's tail, which is unique in
+        // the file.
+        $needle = "            GroupVisibility = ChangeGroupVisibility\n"
+                . "        }\n";
+
+        $converter = <<<'CS'
+            GroupVisibility = ChangeGroupVisibility
+        }
+
+        /// <summary>
+        /// Serializes SubFormFieldRuleAction.TypeEnum to and from the
+        /// OpenAPI wire values (change-field-visibility,
+        /// change-group-visibility). The switch is driven by the
+        /// underlying numeric value so that legacy alias members
+        /// (FieldVisibility, GroupVisibility) serialize identically to
+        /// their canonical counterparts.
+        /// </summary>
+        public class TypeEnumJsonConverter : JsonConverter<TypeEnum>
+        {
+            public override void WriteJson(JsonWriter writer, TypeEnum value, JsonSerializer serializer)
+            {
+                switch (value)
+                {
+                    case TypeEnum.ChangeFieldVisibility:
+                        writer.WriteValue("change-field-visibility");
+                        return;
+                    case TypeEnum.ChangeGroupVisibility:
+                        writer.WriteValue("change-group-visibility");
+                        return;
+                    default:
+                        throw new JsonSerializationException(
+                            $"Unknown value for SubFormFieldRuleAction.TypeEnum: {(int)value}");
+                }
+            }
+
+            public override TypeEnum ReadJson(JsonReader reader, Type objectType, TypeEnum existingValue, bool hasExistingValue, JsonSerializer serializer)
+            {
+                if (reader.TokenType == JsonToken.Null)
+                {
+                    throw new JsonSerializationException(
+                        "Cannot deserialize null into SubFormFieldRuleAction.TypeEnum");
+                }
+
+                var raw = reader.Value?.ToString();
+                switch (raw)
+                {
+                    case "change-field-visibility":
+                        return TypeEnum.ChangeFieldVisibility;
+                    case "change-group-visibility":
+                        return TypeEnum.ChangeGroupVisibility;
+                    default:
+                        throw new JsonSerializationException(
+                            $"Unknown wire value for SubFormFieldRuleAction.TypeEnum: {raw}");
+                }
+            }
+        }
+
+CS;
+
+        return str_replace($needle, $converter, $contents);
     }
 }
 
 $copier = new CopyConstants();
-$copier->run();
+$copier->run();

sdks/dotnet/src/Dropbox.Sign.Test/Model/SubFormFieldRuleActionTests.cs

@@ -0,0 +1,84 @@
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using Xunit;
+using Dropbox.Sign.Model;
+
+namespace Dropbox.Sign.Test.Model
+{
+    public class SubFormFieldRuleActionTests
+    {
+        // SubFormFieldRuleAction.TypeEnum must serialize to the exact
+        // wire values accepted by the Dropbox Sign API
+        // (change-field-visibility, change-group-visibility). The enum
+        // intentionally carries legacy alias members (FieldVisibility,
+        // GroupVisibility) that share a numeric value with the canonical
+        // members, so at runtime they are indistinguishable (xUnit also
+        // dedups the alias rows because [InlineData] compares enums by
+        // their underlying int). The dedicated TypeEnumJsonConverter
+        // maps by underlying value so both names produce the same wire
+        // string; pinning the canonical members is therefore sufficient.
+        [Theory]
+        [InlineData(SubFormFieldRuleAction.TypeEnum.ChangeFieldVisibility, "change-field-visibility")]
+        [InlineData(SubFormFieldRuleAction.TypeEnum.ChangeGroupVisibility, "change-group-visibility")]
+        public void TypeEnum_Serializes_To_EnumMember_Value(
+            SubFormFieldRuleAction.TypeEnum value,
+            string expected)
+        {
+            var json = JsonConvert.SerializeObject(value);
+
+            Assert.Equal($"\"{expected}\"", json);
+        }
+
+        [Theory]
+        [InlineData(SubFormFieldRuleAction.TypeEnum.ChangeFieldVisibility, "change-field-visibility")]
+        [InlineData(SubFormFieldRuleAction.TypeEnum.ChangeGroupVisibility, "change-group-visibility")]
+        public void Action_Payload_Uses_EnumMember_Value_For_Type(
+            SubFormFieldRuleAction.TypeEnum value,
+            string expected)
+        {
+            var action = new SubFormFieldRuleAction(
+                fieldId: "api_id_2",
+                hidden: true,
+                type: value
+            );
+
+            var json = JObject.Parse(action.ToJson());
+
+            Assert.Equal(expected, (string)json["type"]);
+        }
+
+        [Theory]
+        [InlineData("change-field-visibility", SubFormFieldRuleAction.TypeEnum.ChangeFieldVisibility)]
+        [InlineData("change-group-visibility", SubFormFieldRuleAction.TypeEnum.ChangeGroupVisibility)]
+        public void Action_Payload_Deserializes_EnumMember_Value_For_Type(
+            string wireValue,
+            SubFormFieldRuleAction.TypeEnum expected)
+        {
+            var payload = new JObject(
+                new JProperty("field_id", "api_id_2"),
+                new JProperty("hidden", true),
+                new JProperty("type", wireValue)
+            ).ToString();
+
+            var action = SubFormFieldRuleAction.Init(payload);
+
+            Assert.Equal(expected, action.Type);
+        }
+
+        [Theory]
+        [InlineData("FieldVisibility")]
+        [InlineData("GroupVisibility")]
+        [InlineData("change-unknown-thing")]
+        [InlineData("")]
+        public void Action_Payload_Rejects_Unknown_Type_Values(string wireValue)
+        {
+            var payload = new JObject(
+                new JProperty("field_id", "api_id_2"),
+                new JProperty("hidden", true),
+                new JProperty("type", wireValue)
+            ).ToString();
+
+            Assert.ThrowsAny<JsonException>(() => SubFormFieldRuleAction.Init(payload));
+        }
+    }
+}

sdks/dotnet/src/Dropbox.Sign/Model/SubFormFieldRuleAction.cs

@@ -36,7 +36,16 @@ public partial class SubFormFieldRuleAction : IEquatable<SubFormFieldRuleAction>
         /// <summary>
         /// Defines Type
         /// </summary>
-        [JsonConverter(typeof(StringEnumConverter))]
+        // A dedicated converter is used instead of StringEnumConverter
+        // because this enum intentionally carries alias members
+        // (FieldVisibility, GroupVisibility) that share a numeric value
+        // with their canonical counterparts. StringEnumConverter goes
+        // through Enum.GetName, which is not guaranteed to pick the
+        // canonical name when multiple members share a value, and
+        // Newtonsoft rejects duplicate [EnumMember] values on the same
+        // enum. Mapping by numeric value here is unambiguous: both the
+        // canonical name and its alias produce the same wire string.
+        [JsonConverter(typeof(TypeEnumJsonConverter))]
         public enum TypeEnum
         {
             /// <summary>
@@ -54,6 +63,54 @@ public enum TypeEnum
             GroupVisibility = ChangeGroupVisibility
         }
 
+        /// <summary>
+        /// Serializes SubFormFieldRuleAction.TypeEnum to and from the
+        /// OpenAPI wire values (change-field-visibility,
+        /// change-group-visibility). The switch is driven by the
+        /// underlying numeric value so that legacy alias members
+        /// (FieldVisibility, GroupVisibility) serialize identically to
+        /// their canonical counterparts.
+        /// </summary>
+        public class TypeEnumJsonConverter : JsonConverter<TypeEnum>
+        {
+            public override void WriteJson(JsonWriter writer, TypeEnum value, JsonSerializer serializer)
+            {
+                switch (value)
+                {
+                    case TypeEnum.ChangeFieldVisibility:
+                        writer.WriteValue("change-field-visibility");
+                        return;
+                    case TypeEnum.ChangeGroupVisibility:
+                        writer.WriteValue("change-group-visibility");
+                        return;
+                    default:
+                        throw new JsonSerializationException(
+                            $"Unknown value for SubFormFieldRuleAction.TypeEnum: {(int)value}");
+                }
+            }
+
+            public override TypeEnum ReadJson(JsonReader reader, Type objectType, TypeEnum existingValue, bool hasExistingValue, JsonSerializer serializer)
+            {
+                if (reader.TokenType == JsonToken.Null)
+                {
+                    throw new JsonSerializationException(
+                        "Cannot deserialize null into SubFormFieldRuleAction.TypeEnum");
+                }
+
+                var raw = reader.Value?.ToString();
+                switch (raw)
+                {
+                    case "change-field-visibility":
+                        return TypeEnum.ChangeFieldVisibility;
+                    case "change-group-visibility":
+                        return TypeEnum.ChangeGroupVisibility;
+                    default:
+                        throw new JsonSerializationException(
+                            $"Unknown wire value for SubFormFieldRuleAction.TypeEnum: {raw}");
+                }
+            }
+        }
+
 
         /// <summary>
         /// Gets or Sets Type

sdks/dotnet/src/Dropbox.Sign/Model/SubFormFieldsPerDocumentDateSigned.cs

@@ -215,7 +215,7 @@ public static SubFormFieldsPerDocumentDateSigned Init(string jsonData)
         /// The initial px font size for the field contents. Can be any integer value between `7` and `49`.  **NOTE:** Font size may be reduced during processing in order to fit the contents within the dimensions of the field.
         /// </summary>
         /// <value>The initial px font size for the field contents. Can be any integer value between &#x60;7&#x60; and &#x60;49&#x60;.  **NOTE:** Font size may be reduced during processing in order to fit the contents within the dimensions of the field.</value>
-        [DataMember(Name = "font_size", EmitDefaultValue = true)]
+        [DataMember(Name = "font_size", EmitDefaultValue = false)]
         public int FontSize { get; set; }
 
         /// <summary>

sdks/dotnet/src/Dropbox.Sign/Model/SubFormFieldsPerDocumentDropdown.cs

@@ -238,7 +238,7 @@ public static SubFormFieldsPerDocumentDropdown Init(string jsonData)
         /// The initial px font size for the field contents. Can be any integer value between `7` and `49`.  **NOTE:** Font size may be reduced during processing in order to fit the contents within the dimensions of the field.
         /// </summary>
         /// <value>The initial px font size for the field contents. Can be any integer value between &#x60;7&#x60; and &#x60;49&#x60;.  **NOTE:** Font size may be reduced during processing in order to fit the contents within the dimensions of the field.</value>
-        [DataMember(Name = "font_size", EmitDefaultValue = true)]
+        [DataMember(Name = "font_size", EmitDefaultValue = false)]
         public int FontSize { get; set; }
 
         /// <summary>

sdks/dotnet/src/Dropbox.Sign/Model/SubFormFieldsPerDocumentHyperlink.cs

@@ -243,7 +243,7 @@ public static SubFormFieldsPerDocumentHyperlink Init(string jsonData)
         /// The initial px font size for the field contents. Can be any integer value between `7` and `49`.  **NOTE:** Font size may be reduced during processing in order to fit the contents within the dimensions of the field.
         /// </summary>
         /// <value>The initial px font size for the field contents. Can be any integer value between &#x60;7&#x60; and &#x60;49&#x60;.  **NOTE:** Font size may be reduced during processing in order to fit the contents within the dimensions of the field.</value>
-        [DataMember(Name = "font_size", EmitDefaultValue = true)]
+        [DataMember(Name = "font_size", EmitDefaultValue = false)]
         public int FontSize { get; set; }
 
         /// <summary>