Introduce explode into autorest

README.md

@@ -30,7 +30,7 @@ pass-thru:
   - subset-reducer
 # version: 3.0.6258
 use-extension:
-  "@autorest/modelerfour": "4.15.378"
+  "@autorest/modelerfour": "4.15.381"
 
 modelerfour:
   group-parameters: true

autorest/codegen/models/operation.py

@@ -15,6 +15,7 @@
 from .schema_request import SchemaRequest
 from .object_schema import ObjectSchema
 from .constant_schema import ConstantSchema
+from .list_schema import ListSchema
 
 
 _LOGGER = logging.getLogger(__name__)
@@ -197,7 +198,7 @@ def build_serialize_data_call(parameter: Parameter, function_name: str) -> str:
         if parameter.skip_url_encoding:
             optional_parameters.append("skip_quote=True")
 
-        if parameter.style:
+        if parameter.style and not parameter.explode:
             if parameter.style in [ParameterStyle.simple, ParameterStyle.form]:
                 div_char = ","
             elif parameter.style in [ParameterStyle.spaceDelimited]:
@@ -210,17 +211,33 @@ def build_serialize_data_call(parameter: Parameter, function_name: str) -> str:
                 raise ValueError(f"Do not support {parameter.style} yet")
             optional_parameters.append(f"div='{div_char}'")
 
-        serialization_constraints = parameter.schema.serialization_constraints
-        optional_parameters += serialization_constraints if serialization_constraints else ""
+        if parameter.explode:
+            if not isinstance(parameter.schema, ListSchema):
+                raise ValueError("Got a explode boolean on a non-array schema")
+            serialization_schema = parameter.schema.element_type
+        else:
+            serialization_schema = parameter.schema
 
-        optional_parameters_string = "" if not optional_parameters else ", " + ", ".join(optional_parameters)
+        serialization_constraints = serialization_schema.serialization_constraints
+        if serialization_constraints:
+            optional_parameters += serialization_constraints
 
         origin_name = parameter.full_serialized_name
 
-        return (
-            f"""self._serialize.{function_name}("{origin_name.lstrip('_')}", {origin_name}, """
-            + f"""'{parameter.schema.serialization_type}'{optional_parameters_string})"""
-        )
+        parameters = [
+            f'"{origin_name.lstrip("_")}"',
+            "q" if parameter.explode else origin_name,
+            f"'{serialization_schema.serialization_type}'",
+            *optional_parameters
+        ]
+        parameters_line = ', '.join(parameters)
+
+        serialize_line = f'self._serialize.{function_name}({parameters_line})'
+
+        if parameter.explode:
+            return f"[{serialize_line} if q is not None else '' for q in {origin_name}]"
+        else:
+            return serialize_line
 
     @property
     def serialization_context(self) -> str:

autorest/codegen/models/parameter.py

@@ -54,6 +54,7 @@ def __init__(
         constraints: List[Any],
         target_property_name: Optional[Union[int, str]] = None,  # first uses id as placeholder
         style: Optional[ParameterStyle] = None,
+        explode: Optional[bool] = False,
         *,
         flattened: bool = False,
         grouped_by: Optional["Parameter"] = None,
@@ -72,6 +73,7 @@ def __init__(
         self.constraints = constraints
         self.target_property_name = target_property_name
         self.style = style
+        self.explode = explode
         self.flattened = flattened
         self.grouped_by = grouped_by
         self.original_parameter = original_parameter
@@ -194,6 +196,7 @@ def from_yaml(cls, yaml_data: Dict[str, Any]) -> "Parameter":
             constraints=[],  # FIXME constraints
             target_property_name=id(yaml_data["targetProperty"]) if yaml_data.get("targetProperty") else None,
             style=ParameterStyle(http_protocol["style"]) if "style" in http_protocol else None,
+            explode=http_protocol["explode"] if "explode" in http_protocol else False,
             grouped_by=yaml_data.get("groupedBy", None),
             original_parameter=yaml_data.get("originalParameter", None),
             flattened=yaml_data.get("flattened", False),

test/vanilla/Expected/AcceptanceTests/UrlMultiCollectionFormat/urlmulticollectionformat/aio/operations_async/_queries_operations_async.py

@@ -65,7 +65,7 @@ async def array_string_multi_null(
         # Construct parameters
         query_parameters = {}  # type: Dict[str, Any]
         if array_query is not None:
-            query_parameters['arrayQuery'] = self._serialize.query("array_query", array_query, '[str]', div=',')
+            query_parameters['arrayQuery'] = [self._serialize.query("array_query", q, 'str') if q is not None else '' for q in array_query]
 
         # Construct headers
         header_parameters = {}  # type: Dict[str, Any]
@@ -92,6 +92,8 @@ async def array_string_multi_empty(
     ) -> None:
         """Get an empty array [] of string using the multi-array format.
 
+        No query parameter should be sent, since the array is empty.
+
         :param array_query: an empty array [] of string using the multi-array format.
         :type array_query: list[str]
         :keyword callable cls: A custom type or function that will be passed the direct response
@@ -109,7 +111,7 @@ async def array_string_multi_empty(
         # Construct parameters
         query_parameters = {}  # type: Dict[str, Any]
         if array_query is not None:
-            query_parameters['arrayQuery'] = self._serialize.query("array_query", array_query, '[str]', div=',')
+            query_parameters['arrayQuery'] = [self._serialize.query("array_query", q, 'str') if q is not None else '' for q in array_query]
 
         # Construct headers
         header_parameters = {}  # type: Dict[str, Any]
@@ -134,11 +136,13 @@ async def array_string_multi_valid(
         array_query: Optional[List[str]] = None,
         **kwargs
     ) -> None:
-        """Get an array of string ['ArrayQuery1', 'begin!*'();:@ &=+$,/?#[]end' , null, ''] using the
-        mult-array format.
+        """Get an array of string using the multi-array format.
+
+        Parameter is ['ArrayQuery1', 'begin!*'();:@ &=+$,/?#[]end' , null, '']. null is sent as empty
+        string.
 
         :param array_query: an array of string ['ArrayQuery1', 'begin!*'();:@ &=+$,/?#[]end' , null,
-         ''] using the mult-array format.
+         ''] using the multi-array format.
         :type array_query: list[str]
         :keyword callable cls: A custom type or function that will be passed the direct response
         :return: None, or the result of cls(response)
@@ -155,7 +159,7 @@ async def array_string_multi_valid(
         # Construct parameters
         query_parameters = {}  # type: Dict[str, Any]
         if array_query is not None:
-            query_parameters['arrayQuery'] = self._serialize.query("array_query", array_query, '[str]', div=',')
+            query_parameters['arrayQuery'] = [self._serialize.query("array_query", q, 'str') if q is not None else '' for q in array_query]
 
         # Construct headers
         header_parameters = {}  # type: Dict[str, Any]

test/vanilla/Expected/AcceptanceTests/UrlMultiCollectionFormat/urlmulticollectionformat/operations/_queries_operations.py

@@ -70,7 +70,7 @@ def array_string_multi_null(
         # Construct parameters
         query_parameters = {}  # type: Dict[str, Any]
         if array_query is not None:
-            query_parameters['arrayQuery'] = self._serialize.query("array_query", array_query, '[str]', div=',')
+            query_parameters['arrayQuery'] = [self._serialize.query("array_query", q, 'str') if q is not None else '' for q in array_query]
 
         # Construct headers
         header_parameters = {}  # type: Dict[str, Any]
@@ -98,6 +98,8 @@ def array_string_multi_empty(
         # type: (...) -> None
         """Get an empty array [] of string using the multi-array format.
 
+        No query parameter should be sent, since the array is empty.
+
         :param array_query: an empty array [] of string using the multi-array format.
         :type array_query: list[str]
         :keyword callable cls: A custom type or function that will be passed the direct response
@@ -115,7 +117,7 @@ def array_string_multi_empty(
         # Construct parameters
         query_parameters = {}  # type: Dict[str, Any]
         if array_query is not None:
-            query_parameters['arrayQuery'] = self._serialize.query("array_query", array_query, '[str]', div=',')
+            query_parameters['arrayQuery'] = [self._serialize.query("array_query", q, 'str') if q is not None else '' for q in array_query]
 
         # Construct headers
         header_parameters = {}  # type: Dict[str, Any]
@@ -141,11 +143,13 @@ def array_string_multi_valid(
         **kwargs  # type: Any
     ):
         # type: (...) -> None
-        """Get an array of string ['ArrayQuery1', 'begin!*'();:@ &=+$,/?#[]end' , null, ''] using the
-        mult-array format.
+        """Get an array of string using the multi-array format.
+
+        Parameter is ['ArrayQuery1', 'begin!*'();:@ &=+$,/?#[]end' , null, '']. null is sent as empty
+        string.
 
         :param array_query: an array of string ['ArrayQuery1', 'begin!*'();:@ &=+$,/?#[]end' , null,
-         ''] using the mult-array format.
+         ''] using the multi-array format.
         :type array_query: list[str]
         :keyword callable cls: A custom type or function that will be passed the direct response
         :return: None, or the result of cls(response)
@@ -162,7 +166,7 @@ def array_string_multi_valid(
         # Construct parameters
         query_parameters = {}  # type: Dict[str, Any]
         if array_query is not None:
-            query_parameters['arrayQuery'] = self._serialize.query("array_query", array_query, '[str]', div=',')
+            query_parameters['arrayQuery'] = [self._serialize.query("array_query", q, 'str') if q is not None else '' for q in array_query]
 
         # Construct headers
         header_parameters = {}  # type: Dict[str, Any]