Fix AnswerLikes null handling and DocumentContent serialization

Author: dhruv7539

src/glean/api_client/_hooks/answer_likes_null_fix_hook.py

@@ -0,0 +1,55 @@
+"""Hook to normalize AnswerLikes payloads that return null likedBy values."""
+
+from typing import Any, Tuple
+
+from glean.api_client._hooks.types import SDKInitHook
+from glean.api_client.httpclient import HttpClient
+
+
+class AnswerLikesNullFixHook(SDKInitHook):
+    """
+    Normalizes API payloads where AnswerLikes.likedBy is null.
+
+    The API can return {"likedBy": null, "likedByUser": ..., "numLikes": ...}
+    even though the generated model expects likedBy to be a list. This hook patches the
+    unmarshal step so SDK responses continue to validate after regeneration.
+    """
+
+    def sdk_init(self, base_url: str, client: HttpClient) -> Tuple[str, HttpClient]:
+        self._patch_unmarshal()
+        return base_url, client
+
+    def _patch_unmarshal(self) -> None:
+        from glean.api_client.utils import serializers
+
+        if getattr(serializers.unmarshal, "_glean_answer_likes_null_fix", False):
+            return
+
+        original_unmarshal = serializers.unmarshal
+
+        def fixed_unmarshal(val: Any, typ: Any) -> Any:
+            return original_unmarshal(self._normalize_answer_likes_nulls(val), typ)
+
+        fixed_unmarshal._glean_answer_likes_null_fix = True
+        serializers.unmarshal = fixed_unmarshal
+
+    def _normalize_answer_likes_nulls(self, val: Any) -> Any:
+        if isinstance(val, list):
+            for item in val:
+                self._normalize_answer_likes_nulls(item)
+            return val
+
+        if isinstance(val, dict):
+            for item in val.values():
+                self._normalize_answer_likes_nulls(item)
+
+            if self._is_answer_likes_payload(val) and val["likedBy"] is None:
+                val["likedBy"] = []
+
+        return val
+
+    @staticmethod
+    def _is_answer_likes_payload(val: Any) -> bool:
+        return isinstance(val, dict) and all(
+            key in val for key in ("likedBy", "likedByUser", "numLikes")
+        )

src/glean/api_client/_hooks/registration.py

@@ -1,4 +1,5 @@
 from .types import Hooks
+from .answer_likes_null_fix_hook import AnswerLikesNullFixHook
 from .server_url_normalizer import ServerURLNormalizerHook
 from .multipart_fix_hook import MultipartFileFieldFixHook
 from .agent_file_upload_error_hook import AgentFileUploadErrorHook
@@ -22,6 +23,9 @@ def init_hooks(hooks: Hooks):
     # Register hook to fix multipart file field names that incorrectly have '[]' suffix
     hooks.register_sdk_init_hook(MultipartFileFieldFixHook())
 
+    # Register hook to normalize null likedBy payloads before response validation
+    hooks.register_sdk_init_hook(AnswerLikesNullFixHook())
+
     # Register hook to provide helpful error messages for agent file upload issues
     hooks.register_after_error_hook(AgentFileUploadErrorHook())
 

tests/test_answer_likes_null_fix_hook.py

@@ -0,0 +1,77 @@
+"""Tests for the AnswerLikes null fix hook."""
+
+from unittest.mock import Mock
+
+from glean.api_client import models
+from glean.api_client._hooks.answer_likes_null_fix_hook import AnswerLikesNullFixHook
+from glean.api_client.httpclient import HttpClient
+from glean.api_client.utils import serializers
+
+
+class TestAnswerLikesNullFixHook:
+    """Test cases for the AnswerLikes null fix hook."""
+
+    def setup_method(self):
+        """Set up test fixtures."""
+        self.hook = AnswerLikesNullFixHook()
+        self.mock_client = Mock(spec=HttpClient)
+
+    def test_sdk_init_returns_unchanged_params(self):
+        """SDK init should not change the base URL or client."""
+        base_url = "https://api.example.com"
+
+        result_url, result_client = self.hook.sdk_init(base_url, self.mock_client)
+
+        assert result_url == base_url
+        assert result_client == self.mock_client
+
+    def test_patch_unmarshal_is_idempotent(self, monkeypatch):
+        """The unmarshal patch should only be applied once."""
+        monkeypatch.setattr(serializers, "unmarshal", serializers.unmarshal)
+
+        self.hook._patch_unmarshal()
+        first = serializers.unmarshal
+
+        self.hook._patch_unmarshal()
+        second = serializers.unmarshal
+
+        assert first is second
+        assert getattr(first, "_glean_answer_likes_null_fix", False) is True
+
+    def test_normalize_answer_likes_nulls_updates_nested_payloads(self):
+        """Nested AnswerLikes payloads should convert null likedBy values to empty lists."""
+        payload = {
+            "message": {
+                "likes": {
+                    "likedBy": None,
+                    "likedByUser": False,
+                    "numLikes": 0,
+                }
+            }
+        }
+
+        normalized = self.hook._normalize_answer_likes_nulls(payload)
+
+        assert normalized is payload
+        assert payload["message"]["likes"]["likedBy"] == []
+
+    def test_normalize_answer_likes_nulls_ignores_non_matching_payloads(self):
+        """Unrelated payloads should not be modified."""
+        payload = {"likedBy": None}
+
+        normalized = self.hook._normalize_answer_likes_nulls(payload)
+
+        assert normalized is payload
+        assert payload["likedBy"] is None
+
+    def test_patched_unmarshal_normalizes_null_liked_by(self, monkeypatch):
+        """Patched unmarshal should make null likedBy payloads validate cleanly."""
+        monkeypatch.setattr(serializers, "unmarshal", serializers.unmarshal)
+        self.hook._patch_unmarshal()
+
+        likes = serializers.unmarshal(
+            {"likedBy": None, "likedByUser": False, "numLikes": 0},
+            models.AnswerLikes,
+        )
+
+        assert likes.liked_by == []

tests/test_model_regressions.py

@@ -0,0 +1,28 @@
+import json
+
+from glean.api_client import Glean, models, utils
+
+
+def test_answer_likes_normalizes_null_liked_by_after_sdk_init():
+    payload = json.dumps(
+        {
+            "likedBy": None,
+            "likedByUser": False,
+            "numLikes": 0,
+        }
+    )
+
+    with Glean(api_token="token", instance="test-instance"):
+        likes = utils.unmarshal_json(payload, models.AnswerLikes)
+
+    assert likes.liked_by == []
+    assert likes.liked_by_user is False
+    assert likes.num_likes == 0
+
+
+def test_document_content_model_dump_keeps_alias_field_value():
+    content = models.DocumentContent(fullTextList=["This is a test document."])
+
+    dumped = content.model_dump()
+
+    assert dumped["fullTextList"] == ["This is a test document."]