fix: TypeError during negative testing on Open API schemas with par…

…ameters that have non-default `style` value

Ref: #1208

docs/changelog.rst

@@ -7,6 +7,7 @@ Changelog
 **Fixed**
 
 - ``KeyError`` when the ``response_schema_conformance`` check is executed against responses without schema definition. `#1220`_
+- ``TypeError`` during negative testing on Open API schemas with parameters that have non-default ``style`` value. `#1208`_
 
 `3.9.3`_ - 2021-06-22
 ---------------------
@@ -2076,6 +2077,7 @@ Deprecated
 .. _0.2.0: https://github.com/schemathesis/schemathesis/compare/v0.1.0...v0.2.0
 
 .. _#1220: https://github.com/schemathesis/schemathesis/issues/1220
+.. _#1208: https://github.com/schemathesis/schemathesis/issues/1208
 .. _#1202: https://github.com/schemathesis/schemathesis/issues/1202
 .. _#1194: https://github.com/schemathesis/schemathesis/issues/1194
 .. _#1190: https://github.com/schemathesis/schemathesis/issues/1190

src/schemathesis/specs/openapi/serialization.py

@@ -1,5 +1,5 @@
 import json
-from typing import Any, Callable, Dict, Generator, List, Optional
+from typing import Any, Callable, Dict, Generator, List, Optional, Tuple, Union
 
 from ...utils import compose
 
@@ -167,7 +167,27 @@ def _map(item: Generated) -> Generated:
 
 
 def make_delimited(data: Optional[Dict[str, Any]], delimiter: str = ",") -> str:
-    return delimiter.join(f"{key}={value}" for key, value in (data or {}).items())
+    return delimiter.join(f"{key}={value}" for key, value in force_dict(data or {}).items())
+
+
+def force_iterable(value: Any) -> Union[List, Tuple]:
+    """Converts the value to a list or a tuple.
+
+    Only relevant for negative test scenarios where the original types might be changed.
+    """
+    if isinstance(value, (tuple, list)):
+        return value
+    return [value]
+
+
+def force_dict(value: Any) -> Dict:
+    """Converts the value to a dictionary.
+
+    Only relevant for negative test scenarios where the original types might be changed.
+    """
+    if isinstance(value, dict):
+        return value
+    return {"": value}
 
 
 @conversion
@@ -178,7 +198,7 @@ def to_json(item: Generated, name: str) -> None:
 
 @conversion
 def delimited(item: Generated, name: str, delimiter: str) -> None:
-    item[name] = delimiter.join(map(str, item[name] or ()))
+    item[name] = delimiter.join(map(str, force_iterable(item[name] or ())))
 
 
 @conversion
@@ -189,14 +209,14 @@ def deep_object(item: Generated, name: str) -> None:
     """
     generated = item.pop(name)
     if generated:
-        item.update({f"{name}[{key}]": value for key, value in generated.items()})
+        item.update({f"{name}[{key}]": value for key, value in force_dict(generated).items()})
     else:
         item[name] = ""
 
 
 @conversion
 def comma_delimited_object(item: Generated, name: str) -> None:
-    item[name] = ",".join(map(str, sum((item[name] or {}).items(), ())))
+    item[name] = ",".join(map(str, sum((force_dict(item[name] or {})).items(), ())))
 
 
 @conversion
@@ -243,7 +263,7 @@ def label_array(item: Generated, name: str, explode: Optional[bool]) -> None:
         delimiter = "."
     else:
         delimiter = ","
-    new = delimiter.join(map(str, item[name] or ()))
+    new = delimiter.join(map(str, force_iterable(item[name] or ())))
     if new:
         item[name] = f".{new}"
     else:
@@ -265,7 +285,7 @@ def label_object(item: Generated, name: str, explode: Optional[bool]) -> None:
     if explode:
         new = make_delimited(item[name], ".")
     else:
-        object_items = map(str, sum((item[name] or {}).items(), ()))
+        object_items = map(str, sum(force_dict(item[name] or {}).items(), ()))
         new = ",".join(object_items)
     if new:
         item[name] = f".{new}"
@@ -299,9 +319,9 @@ def matrix_array(item: Generated, name: str, explode: Optional[bool]) -> None:
         id=[3, 4, 5] => ";id=3,4,5"
     """
     if explode:
-        new = ";".join(f"{name}={value}" for value in item[name] or ())
+        new = ";".join(f"{name}={value}" for value in force_iterable(item[name] or ()))
     else:
-        new = ",".join(map(str, item[name] or ()))
+        new = ",".join(map(str, force_iterable(item[name] or ())))
     if new:
         item[name] = f";{new}"
     else:
@@ -323,7 +343,7 @@ def matrix_object(item: Generated, name: str, explode: Optional[bool]) -> None:
     if explode:
         new = make_delimited(item[name], ";")
     else:
-        object_items = map(str, sum((item[name] or {}).items(), ()))
+        object_items = map(str, sum(force_dict(item[name] or {}).items(), ()))
         new = ",".join(object_items)
     if new:
         item[name] = f";{new}"

test/specs/openapi/test_negative.py

@@ -1,4 +1,5 @@
 from copy import deepcopy
+from test.utils import assert_requests_call
 
 import pytest
 from hypothesis import HealthCheck, given, settings
@@ -7,6 +8,8 @@
 from hypothesis_jsonschema._canonicalise import FALSEY, canonicalish
 from jsonschema import Draft4Validator
 
+import schemathesis
+from schemathesis import DataGenerationMethod
 from schemathesis.specs.openapi._hypothesis import STRING_FORMATS, is_valid_header
 from schemathesis.specs.openapi.constants import LOCATION_TO_CONTAINER
 from schemathesis.specs.openapi.negative import mutated, negative_schema
@@ -269,3 +272,46 @@ def test_no_unsatisfiable_schemas(data):
     schema = {"type": "object", "required": ["foo"]}
     mutated_schema = data.draw(mutated(schema, location="body", media_type="application/json"))
     assert canonicalish(mutated_schema) != FALSEY
+
+
+ARRAY_PARAMETER = {"type": "array", "minItems": 1, "items": {"type": "string", "format": "ipv4"}}
+OBJECT_PARAMETER = {
+    "type": "object",
+    "minProperties": 1,
+    "properties": {"foo": {"type": "string", "format": "ipv4"}, "bar": {"type": "string", "format": "ipv4"}},
+    "additionalProperties": False,
+}
+
+
+@pytest.mark.parametrize("explode", (True, False))
+@pytest.mark.parametrize(
+    "location, schema, style",
+    [("query", ARRAY_PARAMETER, style) for style in ("pipeDelimited", "spaceDelimited")]
+    + [("query", OBJECT_PARAMETER, "deepObject")]
+    + [
+        ("path", parameter, style)
+        for parameter in [OBJECT_PARAMETER, ARRAY_PARAMETER]
+        for style in ("simple", "label", "matrix")
+    ],
+)
+@pytest.mark.hypothesis_nested
+def test_non_default_styles(empty_open_api_3_schema, location, schema, style, explode):
+    # See GH-1208
+    # When the schema contains a parameter with a not-default "style"
+    empty_open_api_3_schema["paths"]["/bug"] = {
+        "get": {
+            "parameters": [
+                {"name": "key", "in": location, "required": True, "style": style, "explode": explode, "schema": schema},
+            ],
+            "responses": {"200": {"description": "OK"}},
+        }
+    }
+
+    schema = schemathesis.from_dict(empty_open_api_3_schema)
+
+    @given(case=schema["/bug"]["get"].as_strategy(data_generation_method=DataGenerationMethod.negative))
+    @settings(deadline=None, max_examples=10, suppress_health_check=[HealthCheck.too_slow, HealthCheck.filter_too_much])
+    def test(case):
+        assert_requests_call(case)
+
+    test()