bug: fix bug in parsing of repeated headers

Closes #19

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "xpresso"
-version = "0.4.3"
+version = "0.4.4"
 description = "A developer centric, performant Python web framework"
 authors = ["Adrian Garcia Badaracco <[email protected]>"]
 readme = "README.md"

tests/test_extractors/params/test_header_extractor.py

@@ -17,7 +17,7 @@
     "headers,status_code,json_response",
     [
         ({"Header": "123"}, 200, {"Header": "123"}),
-        ({"Header": "1,2,3"}, 200, {"Header": "1,2,3"}),
+        ({"Header": "1,2,3"}, 200, {"Header": "1"}),
         ({"Header": ""}, 200, {"Header": ""}),
     ],
 )
@@ -47,16 +47,8 @@ async def test(header: Annotated[str, HeaderParam(explode=explode)]) -> Any:
         ({"Header": "123"}, 200, {"Header": 123}),
         (
             {"Header": "1,2,3"},
-            422,
-            {
-                "detail": [
-                    {
-                        "loc": ["header", "header"],
-                        "msg": "value is not a valid integer",
-                        "type": "type_error.integer",
-                    }
-                ]
-            },
+            200,
+            {"Header": 1},
         ),
         (
             {"Header": ""},
@@ -111,6 +103,7 @@ async def test(header: Annotated[int, HeaderParam(explode=explode)]) -> Any:
     [
         ({"Header": "1,2"}, 200, {"Header": ["1", "2"]}),
         ({"Header": "1,2,"}, 200, {"Header": ["1", "2", ""]}),
+        ({"Header": "1, 2"}, 200, {"Header": ["1", "2"]}),
         ({"Header": ""}, 200, {"Header": []}),
         ({"Header": ","}, 200, {"Header": ["", ""]}),
         ({}, 200, {"Header": []}),
@@ -153,6 +146,7 @@ async def test(header: Annotated[List[str], HeaderParam(explode=explode)]) -> An
                 ]
             },
         ),
+        ({"Header": "1, 2"}, 200, {"Header": [1, 2]}),
         ({"Header": ""}, 200, {"Header": []}),
         (
             {"Header": ","},
@@ -200,6 +194,7 @@ async def test(header: Annotated[List[int], HeaderParam(explode=explode)]) -> An
     [
         # explode = True
         (True, {"Header": "foo=1,bar=2"}, 200, {"foo": 1, "bar": "2", "baz": "3"}),
+        (True, {"Header": "foo=1, bar=2"}, 200, {"foo": 1, "bar": "2", "baz": "3"}),
         (
             True,
             {"Header": "foo=1,bar=2,baz=4"},
@@ -284,6 +279,7 @@ async def test(header: Annotated[List[int], HeaderParam(explode=explode)]) -> An
         ),
         # explode = False
         (False, {"Header": "foo,1,bar,2"}, 200, {"foo": 1, "bar": "2", "baz": "3"}),
+        (False, {"Header": "foo, 1, bar, 2"}, 200, {"foo": 1, "bar": "2", "baz": "3"}),
         (
             False,
             {"Header": "foo,1,bar,2,baz,4"},

xpresso/binders/_extractors/params/header.py

@@ -25,10 +25,19 @@
 from xpresso.typing import Some
 
 
+def collect_scalar(value: Optional[str]) -> Optional[Some[str]]:
+    if value is None:
+        return None
+    split = value.split(",")
+    if len(split) == 1:
+        return Some(split[0])
+    return Some(next(iter(split)))
+
+
 def collect_sequence(value: Optional[str]) -> Optional[Some[List[str]]]:
     if not value:
         return Some(cast(List[str], []))
-    return Some(value.split(","))
+    return Some([v.lstrip() for v in value.split(",")])
 
 
 def collect_object(
@@ -44,10 +53,12 @@ def collect_object(
             if len(split) == 1 or not field or field[0] == "=":
                 raise InvalidSerialization(f"invalid object style header: {value}")
             name, val = split
-            res[name] = val
+            res[name.lstrip()] = val
         return Some(res)
     try:
-        groups = cast(Iterable[Tuple[str, str]], grouped(value.split(",")))
+        groups = cast(
+            Iterable[Tuple[str, str]], grouped([v.lstrip() for v in value.split(",")])
+        )
     except ValueError:
         raise InvalidSerialization(f"invalid object style header: {value}")
     return Some(dict(groups))
@@ -65,7 +76,7 @@ def get_extractor(explode: bool, field: ModelField) -> Extractor:
     if is_mapping_like(field):
         return functools.partial(collect_object, explode)
     # single item
-    return lambda value: Some(value) if value is not None else None
+    return collect_scalar
 
 
 ERRORS = {
@@ -87,12 +98,21 @@ async def extract(
         send: starlette.types.Send,
         connection: HTTPConnection,
     ) -> Any:
-        param_value: "Optional[str]" = None
+        # parse headers according to RFC 7230
+        # this means treating repeated headers and "," seperated ones the same
+        # so here we merge them all into one "," seperated string
+        # also note that whitespaces after a "," don't matter, so we .lstrip() as needed
+        header_values: "List[str]" = []
         for name, value in scope["headers"]:
             if name == self.header_name:
-                param_value = value.decode("latin-1")
+                header_values.append(value.decode("latin-1"))
+        header_value: "Optional[str]"
+        if header_values:
+            header_value = ",".join(header_values)
+        else:
+            header_value = None
         try:
-            extracted = self.extractor(param_value)
+            extracted = self.extractor(header_value)
         except InvalidSerialization as exc:
             raise ERRORS[scope["type"]](
                 [ErrorWrapper(exc=exc, loc=("header", self.name))]