fix: preserve int64 precision for typed fields in keepAllInAdditional mode

When _keepTypedInAdditionalProperties is true, known typed attributes are now
deserialized with their declared type/format before being stored in
additionalProperties. This routes int64 fields through the BigInt conversion
path instead of raw JSON number assignment. Also removes the redundant
instance.additionalProperties initialization guard that was immediately
overwritten.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: charlie-zhang109

packages/datadog-api-client-v1/models/ObjectSerializer.ts

@@ -3350,21 +3350,34 @@ export class ObjectSerializer {
 
       if (extraAttributes.length > 0) {
         if ("additionalProperties" in attributesMap) {
-          if (!instance.additionalProperties) {
-            instance.additionalProperties = {};
-          }
-
           const additionalProperties: { [key: string]: any } = {};
-          for (const key of extraAttributes) {
-            additionalProperties[key] = data[key];
+          if (keepAllInAdditional) {
+            // Build reverse map from JSON baseName → attribute config for per-field deserialization.
+            // This preserves int64 precision for typed numeric fields via their declared format.
+            const baseNameToAttr: { [key: string]: any } = {};
+            for (const attrName in attributesMap) {
+              if (attrName !== "additionalProperties") {
+                baseNameToAttr[attributesMap[attrName].baseName] = attributesMap[attrName];
+              }
+            }
+            for (const key of extraAttributes) {
+              const attrInfo = baseNameToAttr[key];
+              additionalProperties[key] = attrInfo
+                ? ObjectSerializer.deserialize(data[key], attrInfo.type, attrInfo.format)
+                : data[key];
+            }
+            instance.additionalProperties = additionalProperties;
+          } else {
+            for (const key of extraAttributes) {
+              additionalProperties[key] = data[key];
+            }
+            const attributeObj = attributesMap["additionalProperties"];
+            instance.additionalProperties = ObjectSerializer.deserialize(
+              additionalProperties,
+              attributeObj.type,
+              attributeObj.format
+            );
           }
-
-          const attributeObj = attributesMap["additionalProperties"];
-          instance.additionalProperties = ObjectSerializer.deserialize(
-            additionalProperties,
-            attributeObj.type,
-            attributeObj.format
-          );
         } else {
           throw new Error(
             `found extra attributes '${extraAttributes}' in ${type}`

packages/datadog-api-client-v2/models/ObjectSerializer.ts

@@ -14366,21 +14366,34 @@ export class ObjectSerializer {
 
       if (extraAttributes.length > 0) {
         if ("additionalProperties" in attributesMap) {
-          if (!instance.additionalProperties) {
-            instance.additionalProperties = {};
-          }
-
           const additionalProperties: { [key: string]: any } = {};
-          for (const key of extraAttributes) {
-            additionalProperties[key] = data[key];
+          if (keepAllInAdditional) {
+            // Build reverse map from JSON baseName → attribute config for per-field deserialization.
+            // This preserves int64 precision for typed numeric fields via their declared format.
+            const baseNameToAttr: { [key: string]: any } = {};
+            for (const attrName in attributesMap) {
+              if (attrName !== "additionalProperties") {
+                baseNameToAttr[attributesMap[attrName].baseName] = attributesMap[attrName];
+              }
+            }
+            for (const key of extraAttributes) {
+              const attrInfo = baseNameToAttr[key];
+              additionalProperties[key] = attrInfo
+                ? ObjectSerializer.deserialize(data[key], attrInfo.type, attrInfo.format)
+                : data[key];
+            }
+            instance.additionalProperties = additionalProperties;
+          } else {
+            for (const key of extraAttributes) {
+              additionalProperties[key] = data[key];
+            }
+            const attributeObj = attributesMap["additionalProperties"];
+            instance.additionalProperties = ObjectSerializer.deserialize(
+              additionalProperties,
+              attributeObj.type,
+              attributeObj.format
+            );
           }
-
-          const attributeObj = attributesMap["additionalProperties"];
-          instance.additionalProperties = ObjectSerializer.deserialize(
-            additionalProperties,
-            attributeObj.type,
-            attributeObj.format
-          );
         } else {
           throw new Error(
             `found extra attributes '${extraAttributes}' in ${type}`