fix(python): file properties now respect custom content type (#4653)

.github/workflows/seed.yml

@@ -1,6 +1,9 @@
 name: seed
 
 on:
+  push:
+    branches:
+      - main 
   pull_request:
     branches:
       - main

generators/python/core_utilities/shared/file.py

@@ -1,28 +1,28 @@
-import typing
+from typing import IO, Dict, List, Mapping, Optional, Tuple, Union, cast
 
 # File typing inspired by the flexibility of types within the httpx library
 # https://github.com/encode/httpx/blob/master/httpx/_types.py
-FileContent = typing.Union[typing.IO[bytes], bytes, str]
-File = typing.Union[
+FileContent = Union[IO[bytes], bytes, str]
+File = Union[
     # file (or bytes)
     FileContent,
     # (filename, file (or bytes))
-    typing.Tuple[typing.Optional[str], FileContent],
+    Tuple[Optional[str], FileContent],
     # (filename, file (or bytes), content_type)
-    typing.Tuple[typing.Optional[str], FileContent, typing.Optional[str]],
+    Tuple[Optional[str], FileContent, Optional[str]],
     # (filename, file (or bytes), content_type, headers)
-    typing.Tuple[
-        typing.Optional[str],
+    Tuple[
+        Optional[str],
         FileContent,
-        typing.Optional[str],
-        typing.Mapping[str, str],
+        Optional[str],
+        Mapping[str, str],
     ],
 ]
 
 
 def convert_file_dict_to_httpx_tuples(
-    d: typing.Dict[str, typing.Union[File, typing.List[File]]],
-) -> typing.List[typing.Tuple[str, File]]:
+    d: Dict[str, Union[File, List[File]]],
+) -> List[Tuple[str, File]]:
     """
     The format we use is a list of tuples, where the first element is the
     name of the file and the second is the file object. Typically HTTPX wants
@@ -39,3 +39,22 @@ def convert_file_dict_to_httpx_tuples(
         else:
             httpx_tuples.append((key, file_like))
     return httpx_tuples
+
+
+def with_content_type(*, file: File, content_type: str) -> File:
+    """ """
+    if isinstance(file, tuple):
+        if len(file) == 2:
+            filename, content = cast(Tuple[Optional[str], FileContent], file)  # type: ignore
+            return (filename, content, content_type)
+        elif len(file) == 3:
+            filename, content, _ = cast(Tuple[Optional[str], FileContent, Optional[str]], file)  # type: ignore
+            return (filename, content, content_type)
+        elif len(file) == 4:
+            filename, content, _, headers = cast(  # type: ignore
+                Tuple[Optional[str], FileContent, Optional[str], Mapping[str, str]], file
+            )
+            return (filename, content, content_type, headers)
+        else:
+            raise ValueError(f"Unexpected tuple length: {len(file)}")
+    return (None, file, content_type)

generators/python/sdk/versions.yml

@@ -1,4 +1,17 @@
 # For unreleased changes, use unreleased.yml
+- version: 4.2.3
+  irVersion: 53
+  changelogEntry:
+    - type: fix
+      summary: |
+        The content type of file properties is now respected for multipart 
+        requests. For example, if you have a file property called `image` that has the 
+        content type `image/jpeg`, then it will be sent as: 
+
+        ```python
+        "image": core.with_content_type(file=image, content_type="image/jpeg"),
+        ````
+
 - version: 4.2.2
   irVersion: 53
   changelogEntry:

generators/python/src/fern_python/generators/sdk/client_generator/request_body_parameters/file_upload_request_body_parameters.py

@@ -145,9 +145,21 @@ def write(writer: AST.NodeWriter) -> None:
                         )
                         writer.write_line(f', "{property_as_union.content_type}"),')
                     elif property_as_union.type == "file":
-                        writer.write_line(
-                            f'"{property_as_union.value.get_as_union().key.wire_value}": {self._get_file_property_name(property_as_union.value)},'
-                        )
+                        file_property_as_union = property_as_union.value.get_as_union()
+                        if file_property_as_union.content_type is not None:
+                            writer.write(f'"{file_property_as_union.key.wire_value}": ')
+                            writer.write_node(
+                                self._context.core_utilities.with_content_type(
+                                    AST.Expression(
+                                        f'file={file_property_as_union.key.wire_value}, content_type="{file_property_as_union.content_type}"'
+                                    )
+                                )
+                            )
+                            writer.write_line(",")
+                        else:
+                            writer.write_line(
+                                f'"{file_property_as_union.key.wire_value}": {self._get_file_property_name(property_as_union.value)},'
+                            )
             writer.write_line("}")
 
         return AST.Expression(AST.CodeWriter(write))

generators/python/src/fern_python/generators/sdk/core_utilities/core_utilities.py

@@ -89,7 +89,7 @@ def copy_to_project(self, *, project: Project) -> None:
                 directories=self.filepath,
                 file=Filepath.FilepathPart(module_name="file"),
             ),
-            exports={"File", "convert_file_dict_to_httpx_tuples"},
+            exports={"File", "convert_file_dict_to_httpx_tuples", "with_content_type"},
         )
         self._copy_file_to_project(
             project=project,
@@ -355,6 +355,19 @@ def httpx_tuple_converter(self, obj: AST.Expression) -> AST.Expression:
             )
         )
 
+    def with_content_type(self, obj: AST.Expression) -> AST.Expression:
+        return AST.Expression(
+            AST.FunctionInvocation(
+                function_definition=AST.Reference(
+                    qualified_name_excluding_import=("with_content_type",),
+                    import_=AST.ReferenceImport(
+                        module=AST.Module.local(*self._module_path_unnamed), named_import="core"
+                    ),
+                ),
+                args=[obj],
+            )
+        )
+
     def http_client(
         self,
         base_client: AST.Expression,

generators/python/tests/utils/test_file.py

@@ -0,0 +1,45 @@
+from typing import Optional, Tuple, cast
+import pytest
+from io import BytesIO
+
+from core_utilities.shared.file import FileContent, with_content_type
+
+
+def test_file_content_bytes() -> None:
+    result = with_content_type(file=b"file content", content_type="text/plain")
+    assert result == (None, b"file content", "text/plain")
+
+def test_file_content_str() -> None:
+    result = with_content_type(file="file content", content_type="text/plain")
+    assert result == (None, "file content", "text/plain")
+
+def test_file_content_io() -> None:
+    file_like = BytesIO(b"file content")
+    result = with_content_type(file=file_like, content_type="text/plain")
+    filename, content, contentType = cast(Tuple[Optional[str], FileContent, Optional[str]], result)
+    assert filename is None
+    assert content == file_like
+    assert contentType == "text/plain"
+
+def test_tuple_2() -> None:
+    result = with_content_type(file=("example.txt", b"file content"), content_type="text/plain")
+    assert result == ("example.txt", b"file content", "text/plain")
+
+def test_tuple_3() -> None:
+    result = with_content_type(file=("example.txt", b"file content", "application/octet-stream"), content_type="text/plain")
+    assert result == ("example.txt", b"file content", "text/plain")
+
+def test_tuple_4() -> None:
+    result = with_content_type(file=("example.txt", b"file content", "application/octet-stream", {"X-Custom": "value"}), content_type="text/plain")
+    assert result == ("example.txt", b"file content", "text/plain", {"X-Custom": "value"})
+
+def test_none_filename() -> None:
+    result = with_content_type(file=(None, b"file content"), content_type="text/plain")
+    assert result == (None, b"file content", "text/plain")
+
+def test_invalid_tuple_length() -> None:
+    with pytest.raises(ValueError):
+        with_content_type(
+            file=("example.txt", b"file content", "text/plain", {}, "extra"), # type: ignore
+            content_type="application/json"
+        )

packages/cli/generation/ir-generator/src/__test__/test-definitions/file-upload.json

@@ -2182,7 +2182,7 @@
                                         "wireValue": "file"
                                     },
                                     "isOptional": false,
-                                    "contentType": null
+                                    "contentType": "application/octet-stream"
                                 }
                             },
                             {