Add tests for parameter_dict_from_yaml_file type and namespace handling

Regression fixtures ahead of #1606 (replace with rcl_parse_yaml_file).
Covers scalar/array types, namespace prepend, nested-key flattening,
malformed YAML, and empty ros__parameters — cases not exercised by
the existing wildcard-focused test.

Signed-off-by: Akihiko Komada <aki1770@gmail.com>

Author: aki1770-del

rclpy/test/test_parameter.py

@@ -18,6 +18,7 @@
 import unittest
 
 import pytest
+import yaml
 from rcl_interfaces.msg import Parameter as ParameterMsg
 from rcl_interfaces.msg import ParameterType
 from rcl_interfaces.msg import ParameterValue
@@ -474,6 +475,121 @@ def test_parameter_dict_from_yaml_file(self) -> None:
                 os.unlink(f.name)
         self.assertRaises(FileNotFoundError, parameter_dict_from_yaml_file, 'unknown_file')
 
+    def test_parameter_dict_from_yaml_file_scalar_types(self) -> None:
+        yaml_string = """
+            /node:
+                ros__parameters:
+                    count: 42
+                    ratio: 3.5
+                    label: foo
+                    flag: true
+            """
+        with NamedTemporaryFile(mode='w', delete=False, suffix='.yaml') as f:
+            f.write(yaml_string)
+            f.flush()
+        try:
+            result = parameter_dict_from_yaml_file(f.name)
+            assert result['count'].value.type == ParameterType.PARAMETER_INTEGER
+            assert result['count'].value.integer_value == 42
+            assert result['ratio'].value.type == ParameterType.PARAMETER_DOUBLE
+            assert result['ratio'].value.double_value == 3.5
+            assert result['label'].value.type == ParameterType.PARAMETER_STRING
+            assert result['label'].value.string_value == 'foo'
+            assert result['flag'].value.type == ParameterType.PARAMETER_BOOL
+            assert result['flag'].value.bool_value is True
+        finally:
+            os.unlink(f.name)
+
+    def test_parameter_dict_from_yaml_file_array_types(self) -> None:
+        yaml_string = """
+            /node:
+                ros__parameters:
+                    bools: [true, false, true]
+                    ints: [1, 2, 3]
+                    doubles: [1.0, 2.5, 3.25]
+                    strings: ['a', 'b', 'c']
+            """
+        with NamedTemporaryFile(mode='w', delete=False, suffix='.yaml') as f:
+            f.write(yaml_string)
+            f.flush()
+        try:
+            result = parameter_dict_from_yaml_file(f.name)
+            assert result['bools'].value.type == ParameterType.PARAMETER_BOOL_ARRAY
+            assert list(result['bools'].value.bool_array_value) == [True, False, True]
+            assert result['ints'].value.type == ParameterType.PARAMETER_INTEGER_ARRAY
+            assert list(result['ints'].value.integer_array_value) == [1, 2, 3]
+            assert result['doubles'].value.type == ParameterType.PARAMETER_DOUBLE_ARRAY
+            assert list(result['doubles'].value.double_array_value) == [1.0, 2.5, 3.25]
+            assert result['strings'].value.type == ParameterType.PARAMETER_STRING_ARRAY
+            assert list(result['strings'].value.string_array_value) == ['a', 'b', 'c']
+        finally:
+            os.unlink(f.name)
+
+    def test_parameter_dict_from_yaml_file_namespace_prepends(self) -> None:
+        yaml_string = """
+            /node:
+                ros__parameters:
+                    foo: 1
+                    bar: 2
+            """
+        with NamedTemporaryFile(mode='w', delete=False, suffix='.yaml') as f:
+            f.write(yaml_string)
+            f.flush()
+        try:
+            result = parameter_dict_from_yaml_file(f.name, namespace='my_ns.')
+            assert 'my_ns.foo' in result
+            assert 'my_ns.bar' in result
+            assert result['my_ns.foo'].name == 'my_ns.foo'
+            assert result['my_ns.foo'].value.integer_value == 1
+        finally:
+            os.unlink(f.name)
+
+    def test_parameter_dict_from_yaml_file_nested_keys_flattened(self) -> None:
+        yaml_string = """
+            /node:
+                ros__parameters:
+                    outer:
+                        inner: 7
+                        leaf: hello
+            """
+        with NamedTemporaryFile(mode='w', delete=False, suffix='.yaml') as f:
+            f.write(yaml_string)
+            f.flush()
+        try:
+            result = parameter_dict_from_yaml_file(f.name)
+            assert 'outer.inner' in result
+            assert 'outer.leaf' in result
+            assert result['outer.inner'].value.integer_value == 7
+            assert result['outer.leaf'].value.string_value == 'hello'
+        finally:
+            os.unlink(f.name)
+
+    def test_parameter_dict_from_yaml_file_malformed_raises(self) -> None:
+        yaml_string = '/node:\n    ros__parameters: [unclosed'
+        with NamedTemporaryFile(mode='w', delete=False, suffix='.yaml') as f:
+            f.write(yaml_string)
+            f.flush()
+        try:
+            with pytest.raises(yaml.YAMLError):
+                parameter_dict_from_yaml_file(f.name)
+        finally:
+            os.unlink(f.name)
+
+    def test_parameter_dict_from_yaml_file_empty_params_raises(self) -> None:
+        yaml_string = """
+            /node:
+                ros__parameters: {}
+            """
+        with NamedTemporaryFile(mode='w', delete=False, suffix='.yaml') as f:
+            f.write(yaml_string)
+            f.flush()
+        try:
+            with pytest.raises(RuntimeError,
+                               match='Param file does not contain any valid parameters'):
+                parameter_dict_from_yaml_file(f.name)
+        finally:
+            os.unlink(f.name)
+
 
 if __name__ == '__main__':
     unittest.main()