[BUGFIX] Render id/pk-only unexpected indices instead of raising (fixes #11933)

When a COMPLETE result provides unexpected_index_column_names and the unexpected
index records carry only the id/pk columns (Spark/SQL paths, and when
exclude_unexpected_values=True), _convert_unexpected_indices_to_df computed an
empty domain_column_name_list and called unexpected_index_df.groupby([]), which
raises ValueError: No group keys passed! and aborted Data Docs rendering.

Aggregate all records into a single row in that case so the count/index table
renders. The domain-column path is unchanged.

Author: anxkhn

great_expectations/render/util.py

@@ -445,9 +445,16 @@ def _convert_unexpected_indices_to_df(
     def _agg_func(y: pd.Series[T]) -> list[T]:  # type: ignore[type-var]  # not yet supported by pandas-stubs
         return list(y)
 
-    all_unexpected_indices: pd.DataFrame = unexpected_index_df.groupby(domain_column_name_list).agg(
-        _agg_func
-    )
+    if domain_column_name_list:
+        all_unexpected_indices: pd.DataFrame = unexpected_index_df.groupby(
+            domain_column_name_list
+        ).agg(_agg_func)
+    else:
+        # The unexpected-index records carry only the ID/PK columns (no domain
+        # column to group on); this happens for Spark/SQL paths and when
+        # exclude_unexpected_values=True. Grouping on an empty list raises
+        # "No group keys passed!", so aggregate every record into a single row.
+        all_unexpected_indices = unexpected_index_df.groupby(by=lambda _: "").agg(_agg_func)
 
     # 2. add count
     col_to_count: str = unexpected_index_column_names[0]

tests/render/test_util.py

@@ -355,6 +355,34 @@ def test_convert_unexpected_indices_to_df_actual_values():
     assert res.iloc[2].tolist() == ["5", 1]
 
 
+def test_convert_unexpected_indices_to_df_only_id_pk_columns():
+    """
+    Records carry only the ID/PK columns (no domain column to group on), which
+    happens for Spark/SQL paths and when exclude_unexpected_values=True. This used
+    to raise "No group keys passed!"; instead the records are aggregated into a
+    single row. See https://github.com/great-expectations/great_expectations/issues/11933
+    """
+    unexpected_index_list = [
+        {"pk_1": 3, "pk_2": "three"},
+        {"pk_1": 4, "pk_2": "four"},
+        {"pk_1": 5, "pk_2": "five"},
+    ]
+    unexpected_index_column_names = ["pk_1", "pk_2"]
+    partial_unexpected_counts = [
+        {"count": 1, "value": "giraffe"},
+        {"count": 1, "value": "lion"},
+        {"count": 1, "value": "zebra"},
+    ]
+
+    res = _convert_unexpected_indices_to_df(
+        unexpected_index_list=unexpected_index_list,
+        unexpected_index_column_names=unexpected_index_column_names,
+        partial_unexpected_counts=partial_unexpected_counts,
+    )
+    assert list(res) == ["pk_1", "pk_2", "Count"]
+    assert res.iloc[0].tolist() == ["3, 4, 5", "three, four, five", 3]
+
+
 def test_truncate_list_of_indices():
     int_indices: List[Union[int, str]] = [4, 5, 6, 7]
     result: str = truncate_list_of_indices(indices=int_indices)
@@ -525,6 +553,37 @@ def test_build_count_and_index_table_with_null():
     ]
 
 
+def test_build_count_and_index_table_only_id_pk_columns():
+    """
+    Records carry only the ID/PK columns (no domain column), so they are
+    aggregated into a single row instead of raising "No group keys passed!".
+    See https://github.com/great-expectations/great_expectations/issues/11933
+    """
+    partial_unexpected_counts = [
+        {"count": 1, "value": "giraffe"},
+        {"count": 1, "value": "lion"},
+        {"count": 1, "value": "zebra"},
+    ]
+    unexpected_index_list = [
+        {"pk_1": 3, "pk_2": "three"},
+        {"pk_1": 4, "pk_2": "four"},
+        {"pk_1": 5, "pk_2": "five"},
+    ]
+    unexpected_count = 3
+    unexpected_index_column_names = ["pk_1", "pk_2"]
+
+    header_row, table_rows = build_count_and_index_table(
+        partial_unexpected_counts=partial_unexpected_counts,
+        unexpected_index_list=unexpected_index_list,
+        unexpected_count=unexpected_count,
+        unexpected_index_column_names=unexpected_index_column_names,
+    )
+    assert header_row == ["Unexpected Value", "Count", "pk_1", "pk_2"]
+    assert table_rows == [
+        ["EMPTY", 3, "3, 4, 5", "three, four, five"],
+    ]
+
+
 def test_build_count_table():
     partial_unexpected_counts = [
         {"count": 3, "value": "giraffe"},