SERVER-59453 Add support for generic BSONArray to IDL

4 files changed, 35 insertions, 3 deletions

diff --git a/buildscripts/idl/idl/binder.py b/buildscripts/idl/idl/binder.py
index 2f1917a6f06..ab50d0bcc35 100644
--- a/buildscripts/idl/idl/binder.py
+++ b/buildscripts/idl/idl/binder.py
@@ -201,7 +201,7 @@ def _validate_type_properties(ctxt, idl_type, syntax_type):
                 ctxt.add_missing_ast_required_field_error(idl_type, syntax_type, idl_type.name,
                                                           "deserializer")
 
-        elif not bson_type in ["object", "bindata"]:
+        elif not bson_type in ["array", "object", "bindata"]:
             if idl_type.deserializer is None:
                 ctxt.add_missing_ast_required_field_error(idl_type, syntax_type, idl_type.name,
                                                           "deserializer")
diff --git a/buildscripts/idl/idl/bson.py b/buildscripts/idl/idl/bson.py
index 3d1e004dbc0..3f8e5190f9d 100644
--- a/buildscripts/idl/idl/bson.py
+++ b/buildscripts/idl/idl/bson.py
@@ -40,7 +40,7 @@ _BSON_TYPE_INFORMATION = {
     "double": {'scalar': True, 'bson_type_enum': 'NumberDouble'},
     "string": {'scalar': True, 'bson_type_enum': 'String'},
     "object": {'scalar': False, 'bson_type_enum': 'Object'},
-    # TODO: add support: "array" : { 'scalar' :  False, 'bson_type_enum' : 'Array'},
+    "array": {'scalar': False, 'bson_type_enum': 'Array'},
     "bindata": {'scalar': True, 'bson_type_enum': 'BinData'},
     "undefined": {'scalar': True, 'bson_type_enum': 'Undefined'},
     "objectid": {'scalar': True, 'bson_type_enum': 'jstOID'},
diff --git a/buildscripts/idl/idl/cpp_types.py b/buildscripts/idl/idl/cpp_types.py
index bb7ec7d0a22..8971d5715c8 100644
--- a/buildscripts/idl/idl/cpp_types.py
+++ b/buildscripts/idl/idl/cpp_types.py
@@ -652,6 +652,34 @@ class _ObjectBsonCppTypeBase(BsonCppTypeBase):
         return "localObject"
 
 
+class _ArrayBsonCppTypeBase(BsonCppTypeBase):
+    """Custom C++ support for array BSON types."""
+
+    def gen_deserializer_expression(self, indented_writer, object_instance):
+        # type: (writer.IndentedTextWriter, str) -> str
+        if self._ast_type.deserializer:
+            indented_writer.write_line(
+                common.template_args('BSONArray localArray(${object_instance}.Obj());',
+                                     object_instance=object_instance))
+            return "localArray"
+
+        # Just pass the BSONObj through without trying to parse it.
+        return common.template_args('BSONArray(${object_instance}.Obj())',
+                                    object_instance=object_instance)
+
+    def has_serializer(self):
+        # type: () -> bool
+        return self._ast_type.serializer is not None
+
+    def gen_serializer_expression(self, indented_writer, expression):
+        # type: (writer.IndentedTextWriter, str) -> str
+        method_name = writer.get_method_name(self._ast_type.serializer)
+        indented_writer.write_line(
+            common.template_args('BSONArray localArray(${expression}.${method_name}());',
+                                 expression=expression, method_name=method_name))
+        return "localArray"
+
+
 class _BinDataBsonCppTypeBase(BsonCppTypeBase):
     """Custom C++ support for all binData BSON types."""
 
@@ -690,6 +718,7 @@ class _BinDataBsonCppTypeBase(BsonCppTypeBase):
 def get_bson_cpp_type(ast_type):
     # type: (ast.Type) -> Optional[BsonCppTypeBase]
     """Get a class that provides custom serialization for the given BSON type."""
+    # pylint: disable=too-many-return-statements
 
     # Does not support list of types
     if len(ast_type.bson_serialization_type) > 1:
@@ -701,6 +730,9 @@ def get_bson_cpp_type(ast_type):
     if ast_type.bson_serialization_type[0] == 'object':
         return _ObjectBsonCppTypeBase(ast_type)
 
+    if ast_type.bson_serialization_type[0] == 'array':
+        return _ArrayBsonCppTypeBase(ast_type)
+
     if ast_type.bson_serialization_type[0] == 'bindata':
         return _BinDataBsonCppTypeBase(ast_type)
 
diff --git a/buildscripts/idl/idl/generator.py b/buildscripts/idl/idl/generator.py
index a20f64bbcd8..51569af4d4f 100644
--- a/buildscripts/idl/idl/generator.py
+++ b/buildscripts/idl/idl/generator.py
@@ -1206,7 +1206,7 @@ class _CppSourceFileWriter(_CppFileWriterBase):
                                             method_name=method_name, expression=expression)
 
             # BSONObjects are allowed to be pass through without deserialization
-            assert ast_type.bson_serialization_type == ['object']
+            assert ast_type.bson_serialization_type in [['object'], ['array']]
             return expression
 
         # Call a static class method with the signature: