Extract list parameters in parse_form_data

When the client prepares the request, it turns list parameters into multiple instances of the same
key. For instance:

`extract_image_block_types=["Image", "Table"]`

becomes

`extract_image_block_types[]="Image"`
`extract_image_block_types[]="Table"`

We need to account for this in our `parse_form_data` helper if we want to use list params in our
hooks. Likewise, we need to go the other way when recreating the request in `create_request_body`.

Author: awalker4

_test_unstructured_client/unit/test_split_pdf_hook.py

@@ -122,7 +122,8 @@ def test_unit_create_response():
 
 
 def test_unit_create_request():
-    """Test create request method properly sets file, Content-Type and Content-Length headers."""
+    """Test create request method properly sets file, Content-Type and Content-Length headers.
+    List parameters should be flattened in the body."""
 
     # Prepare test data
     request = requests.PreparedRequest()
@@ -133,27 +134,27 @@ def test_unit_create_request():
     form_data = {
         "parameter_1": "value_1",
         "parameter_2": "value_2",
+        "list_parameter": ["value_1", "value_2"],
     }
     page = (io.BytesIO(b"page_content"), 1)
     filename = "test_file.pdf"
 
     # Expected results
-    expected_payload = {
-        "parameter_1": "value_1",
-        "parameter_2": "value_2",
-        "split_pdf_page": "false",
-        "starting_page_number": "7",
-    }
     expected_page_filename = "test_file.pdf"
     expected_body = MultipartEncoder(
-        fields={
-            **expected_payload,
-            "files": (
+        fields=[
+            ("parameter_1", "value_1"),
+            ("parameter_2", "value_2"),
+            ("list_parameter", "value_1"),
+            ("list_parameter", "value_2"),
+            ("split_pdf_page", "false"),
+            ("starting_page_number", "7"),
+            ("files", (
                 expected_page_filename,
                 page[0],
                 "application/pdf",
-            ),
-        }
+            )),
+        ]
     )
     expected_url = ""
 
@@ -164,7 +165,10 @@ def test_unit_create_request():
     # Assert the request object
     assert request_obj.method == "POST"
     assert request_obj.url == expected_url
-    assert request_obj.data.fields == expected_body.fields
+
+    # Validate fields ignoring order
+    assert set(request_obj.data.fields) == set(expected_body.fields)
+
     assert request_content_type.startswith("multipart/form-data")
 
 
@@ -191,11 +195,37 @@ def test_unit_decode_content_disposition():
 
 
 def test_unit_parse_form_data():
-    """Test parse form data method properly parses the form data and returns dictionary."""
+    """Test parse form data method properly parses the form data and returns dictionary.
+    Parameters with the same key should be consolidated to a list."""
 
     # Prepare test data
+    test_form_data = (
+        b"--boundary\r\n"
+        b"Content-Disposition: form-data; name=\"files\"; filename=\"test_file.pdf\"\r\n"
+        b"\r\n"
+        b"file_content\r\n"
+        b"--boundary\r\n"
+        b"Content-Disposition: form-data; name=\"parameter_1\"\r\n"
+        b"\r\n"
+        b"value_1\r\n"
+        b"--boundary\r\n"
+        b"Content-Disposition: form-data; name=\"parameter_2\"\r\n"
+        b"\r\n"
+        b"value_2\r\n"
+        b"--boundary\r\n"
+        b"Content-Disposition: form-data; name=\"list_parameter\"\r\n"
+        b"\r\n"
+        b"value_1\r\n"
+        b"--boundary\r\n"
+        b"Content-Disposition: form-data; name=\"list_parameter\"\r\n"
+        b"\r\n"
+        b"value_2\r\n"
+        b"--boundary--\r\n"
+    )
+
+
     decoded_data = MultipartDecoder(
-        b'--boundary\r\nContent-Disposition: form-data; name="files"; filename="test_file.pdf"\r\n\r\nfile_content\r\n--boundary\r\nContent-Disposition: form-data; name="parameter_1"\r\n\r\nvalue_1\r\n--boundary\r\nContent-Disposition: form-data; name="parameter_2"\r\n\r\nvalue_2\r\n--boundary--\r\n',
+        test_form_data,
         "multipart/form-data; boundary=boundary",
     )
 
@@ -204,6 +234,7 @@ def test_unit_parse_form_data():
         "files": shared.Files(b"file_content", "test_file.pdf"),
         "parameter_1": "value_1",
         "parameter_2": "value_2",
+        "list_parameter": ["value_1", "value_2"],
     }
 
     # Parse form data
@@ -212,6 +243,7 @@ def test_unit_parse_form_data():
     # Assert the parsed form data
     assert form_data.get("parameter_1") == expected_form_data.get("parameter_1")
     assert form_data.get("parameter_2") == expected_form_data.get("parameter_2")
+    assert form_data.get("list_parameter") == expected_form_data.get("list_parameter")
     assert form_data.get("files").file_name == expected_form_data.get("files").file_name
 
     assert form_data.get("files").content == expected_form_data.get("files").content

src/unstructured_client/_hooks/custom/form_utils.py

@@ -9,7 +9,7 @@
 from unstructured_client.models import shared
 
 logger = logging.getLogger(UNSTRUCTURED_CLIENT_LOGGER_NAME)
-FormData = dict[str, Union[str, shared.Files]]
+FormData = dict[str, Union[str, shared.Files, list[str]]]
 
 PARTITION_FORM_FILES_KEY = "files"
 PARTITION_FORM_SPLIT_PDF_PAGE_KEY = "split_pdf_page"
@@ -148,6 +148,13 @@ def parse_form_data(decoded_data: MultipartDecoder) -> FormData:
                 raise ValueError("Filename can't be an empty string.")
             form_data[PARTITION_FORM_FILES_KEY] = shared.Files(part.content, filename)
         else:
-            form_data[name] = part.content.decode()
+            content = part.content.decode()
+            if name in form_data:
+                if isinstance(form_data[name], list):
+                    form_data[name].append(content)
+                else:
+                    form_data[name] = [form_data[name], content]
+            else:
+                form_data[name] = content
 
     return form_data

src/unstructured_client/_hooks/custom/request_utils.py

@@ -5,7 +5,7 @@
 import io
 import json
 import logging
-from typing import Optional, Tuple
+from typing import Optional, Tuple, Any
 
 import httpx
 import requests
@@ -27,16 +27,24 @@ def create_request_body(
     form_data: FormData, page_content: io.BytesIO, filename: str, page_number: int
 ) -> MultipartEncoder:
     payload = prepare_request_payload(form_data)
+
+    payload_fields:  list[tuple[str, Any]] = []
+    for key, value in payload.items():
+        if isinstance(value, list):
+            payload_fields.extend([(key, list_value) for list_value in value])
+        else:
+            payload_fields.append((key, value))
+
+    payload_fields.append((PARTITION_FORM_FILES_KEY, (
+        filename,
+        page_content,
+        "application/pdf",
+    )))
+
+    payload_fields.append((PARTITION_FORM_STARTING_PAGE_NUMBER_KEY, str(page_number)))
+
     body = MultipartEncoder(
-        fields={
-            **payload,
-            PARTITION_FORM_FILES_KEY: (
-                filename,
-                page_content,
-                "application/pdf",
-            ),
-            PARTITION_FORM_STARTING_PAGE_NUMBER_KEY: str(page_number),
-        }
+        fields=payload_fields
     )
     return body