chore(config): Creates yaml_utils.py in utils to allow adk dump yaml in the same style

src/google/adk/utils/yaml_utils.py

@@ -0,0 +1,66 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Union
+
+from pydantic import BaseModel
+import yaml
+
+
+def dump_pydantic_to_yaml(
+    model: BaseModel,
+    file_path: Union[str, Path],
+    *,
+    indent: int = 2,
+    sort_keys: bool = True,
+    exclude_none: bool = True,
+) -> None:
+  """Dump a Pydantic model to a YAML file with multiline strings using | style.
+
+  Args:
+    model: The Pydantic model instance to dump.
+    file_path: Path to the output YAML file.
+    indent: Number of spaces for indentation (default: 2).
+    sort_keys: Whether to sort dictionary keys (default: True).
+    exclude_none: Exclude fields with None values (default: True).
+  """
+  model_dict = model.model_dump(exclude_none=exclude_none)
+
+  file_path = Path(file_path)
+  file_path.parent.mkdir(parents=True, exist_ok=True)
+
+  # Create a custom dumper class
+  class _MultilineDumper(yaml.SafeDumper):
+    pass
+
+  def multiline_str_representer(dumper, data):
+    if '\n' in data:
+      return dumper.represent_scalar('tag:yaml.org,2002:str', data, style='|')
+    return dumper.represent_scalar('tag:yaml.org,2002:str', data)
+
+  # Add representer only to our custom dumper
+  _MultilineDumper.add_representer(str, multiline_str_representer)
+
+  with file_path.open('w', encoding='utf-8') as f:
+    yaml.dump(
+        model_dict,
+        f,
+        Dumper=_MultilineDumper,
+        indent=indent,
+        sort_keys=sort_keys,
+        default_flow_style=False,
+    )

tests/unittests/utils/test_yaml_utils.py

@@ -0,0 +1,71 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for YAML utility functions."""
+
+from pathlib import Path
+from typing import Optional
+
+from google.adk.utils.yaml_utils import dump_pydantic_to_yaml
+from pydantic import BaseModel
+
+
+class SimpleModel(BaseModel):
+  """Simple test model."""
+
+  name: str
+  age: int
+  active: bool
+  multiline_text: Optional[str] = None
+
+
+def test_yaml_file_generation(tmp_path: Path):
+  """Test that YAML file is correctly generated."""
+  model = SimpleModel(name="Alice", age=30, active=True)
+  yaml_file = tmp_path / "test.yaml"
+
+  dump_pydantic_to_yaml(model, yaml_file)
+
+  assert yaml_file.read_text(encoding="utf-8") == """\
+active: true
+age: 30
+name: Alice
+"""
+
+
+def test_multiline_string_pipe_style(tmp_path: Path):
+  """Test that multiline strings use | style."""
+  multiline_text = """\
+This is a long description
+that spans multiple lines
+and should be formatted with pipe style"""
+  model = SimpleModel(
+      name="Test",
+      age=25,
+      active=False,
+      multiline_text=multiline_text,
+  )
+  yaml_file = tmp_path / "test.yaml"
+
+  dump_pydantic_to_yaml(model, yaml_file)
+
+  assert yaml_file.read_text(encoding="utf-8") == """\
+active: false
+age: 25
+multiline_text: |-
+  This is a long description
+  that spans multiple lines
+  and should be formatted with pipe style
+name: Test
+"""