fix: Update data source timestamp inference error message to make sen…

…se (#2636)

Signed-off-by: Achal Shah <[email protected]>

sdk/python/feast/inference.py

@@ -55,30 +55,30 @@ def update_data_sources_with_inferred_event_timestamp_col(
             )
 
             # loop through table columns to find singular match
-            timestamp_field, matched_flag = None, False
+            timestamp_fields = []
             for (
                 col_name,
                 col_datatype,
             ) in data_source.get_table_column_names_and_types(config):
                 if re.match(ts_column_type_regex_pattern, col_datatype):
-                    if matched_flag:
-                        raise RegistryInferenceFailure(
-                            "DataSource",
-                            f"""
-                            {ERROR_MSG_PREFIX} due to multiple possible columns satisfying
-                            the criteria. {ts_column_type_regex_pattern} {col_name}
-                            """,
-                        )
-                    matched_flag = True
-                    timestamp_field = col_name
-            if matched_flag:
-                assert timestamp_field
-                data_source.timestamp_field = timestamp_field
+                    timestamp_fields.append(col_name)
+
+            if len(timestamp_fields) > 1:
+                raise RegistryInferenceFailure(
+                    "DataSource",
+                    f"""{ERROR_MSG_PREFIX}; found multiple possible columns of timestamp type.
+                    Data source type: {data_source.__class__.__name__},
+                    Timestamp regex: `{ts_column_type_regex_pattern}`, columns: {timestamp_fields}""",
+                )
+            elif len(timestamp_fields) == 1:
+                data_source.timestamp_field = timestamp_fields[0]
             else:
                 raise RegistryInferenceFailure(
                     "DataSource",
                     f"""
-                    {ERROR_MSG_PREFIX} due to an absence of columns that satisfy the criteria.
+                    {ERROR_MSG_PREFIX}; Found no columns of timestamp type.
+                    Data source type: {data_source.__class__.__name__},
+                    Timestamp regex: `{ts_column_type_regex_pattern}`.
                     """,
                 )