Add tests for allOf --use-default and --force-optional coverage

Cover the previously uncovered code paths:
- allOf with $ref + sub-schema required fields + --use-default
- allOf with outer required fields + --force-optional

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: butvinm

tests/data/expected/main/jsonschema/allof_required_use_default.py

@@ -0,0 +1,16 @@
+# generated by datamodel-codegen:
+#   filename:  allof_required_use_default.json
+#   timestamp: 2019-07-26T00:00:00+00:00
+
+from __future__ import annotations
+
+from pydantic import BaseModel
+
+
+class Base(BaseModel):
+    id: int
+
+
+class Container(Base):
+    name: str = 'unnamed'
+    tag: str

tests/data/expected/main/jsonschema/force_optional_required.py

@@ -0,0 +1,16 @@
+# generated by datamodel-codegen:
+#   filename:  force_optional_required.json
+#   timestamp: 2019-07-26T00:00:00+00:00
+
+from __future__ import annotations
+
+from pydantic import BaseModel
+
+
+class Base(BaseModel):
+    id: int | None = None
+
+
+class Container(Base):
+    name: str | None = None
+    value: int | None = None

tests/data/jsonschema/allof_required_use_default.json

@@ -0,0 +1,31 @@
+{
+    "$schema": "http://json-schema.org/draft-07/schema",
+    "title": "Container",
+    "definitions": {
+        "Base": {
+            "type": "object",
+            "properties": {
+                "id": {
+                    "type": "integer"
+                }
+            },
+            "required": ["id"]
+        }
+    },
+    "allOf": [
+        {"$ref": "#/definitions/Base"},
+        {
+            "type": "object",
+            "properties": {
+                "name": {
+                    "type": "string",
+                    "default": "unnamed"
+                },
+                "tag": {
+                    "type": "string"
+                }
+            },
+            "required": ["name", "tag"]
+        }
+    ]
+}

tests/data/jsonschema/force_optional_required.json

@@ -0,0 +1,29 @@
+{
+    "$schema": "http://json-schema.org/draft-07/schema",
+    "title": "Container",
+    "definitions": {
+        "Base": {
+            "type": "object",
+            "properties": {
+                "id": {
+                    "type": "integer"
+                }
+            }
+        }
+    },
+    "allOf": [
+        {"$ref": "#/definitions/Base"},
+        {
+            "type": "object",
+            "properties": {
+                "name": {
+                    "type": "string"
+                },
+                "value": {
+                    "type": "integer"
+                }
+            }
+        }
+    ],
+    "required": ["name", "value"]
+}

tests/main/jsonschema/test_main_jsonschema.py

@@ -4753,6 +4753,28 @@ def test_all_of_use_default(output_file: Path) -> None:
     )
 
 
+def test_allof_required_use_default(output_file: Path) -> None:
+    """Test allOf with required fields and --use-default renders defaults without nullable types."""
+    run_main_and_assert(
+        input_path=JSON_SCHEMA_DATA_PATH / "allof_required_use_default.json",
+        output_path=output_file,
+        input_file_type="jsonschema",
+        assert_func=assert_file_content,
+        extra_args=["--use-default"],
+    )
+
+
+def test_force_optional_required(output_file: Path) -> None:
+    """Test --force-optional makes required fields optional."""
+    run_main_and_assert(
+        input_path=JSON_SCHEMA_DATA_PATH / "force_optional_required.json",
+        output_path=output_file,
+        input_file_type="jsonschema",
+        assert_func=assert_file_content,
+        extra_args=["--force-optional"],
+    )
+
+
 def test_main_root_one_of(output_dir: Path) -> None:
     """Test root-level oneOf schemas."""
     run_main_and_assert(