Validate fixed-size parameter defaults during generation

generate_parameter_library_py/generate_parameter_library_py/parse_yaml.py

@@ -103,6 +103,46 @@ def validation_base_name(function_name: str):
     return function_name.replace('<>', '')
 
 
+@typechecked
+def validate_fixed_default_size(
+    param_name: str,
+    defined_type: str,
+    default_value: Any,
+    validations_dict: dict,
+):
+    capacity = fixed_type_size(defined_type)
+    if capacity is None or default_value is None:
+        return
+    if array_type(defined_type) and not isinstance(default_value, list):
+        return
+    if not array_type(defined_type) and not isinstance(default_value, str):
+        return
+
+    default_size = len(default_value)
+    if default_size > capacity:
+        raise compile_error(
+            'Parameter {} has a default value of size {}, which exceeds '
+            "the capacity of type '{}' ({}).".format(
+                param_name, default_size, defined_type, capacity
+            )
+        )
+
+    for function_name, arguments in validations_dict.items():
+        if validation_base_name(function_name) != 'fixed_size':
+            continue
+
+        expected_size = arguments
+        if isinstance(arguments, list) and len(arguments) == 1:
+            expected_size = arguments[0]
+        if isinstance(expected_size, int) and default_size != expected_size:
+            raise compile_error(
+                'Parameter {} has a default value of size {}, but its '
+                "'fixed_size' validation requires {}.".format(
+                    param_name, default_size, expected_size
+                )
+            )
+
+
 @typechecked
 def validate_validator_combinations(param_name: str, validations_dict: dict):
     validation_names = {validation_base_name(name) for name in validations_dict}
@@ -776,6 +816,10 @@ def preprocess_inputs(language, name, value, nested_name_list):
 
     # optional attributes
     default_value = value.get('default_value', None)
+    validations_dict = value.get('validation', {})
+    validate_fixed_default_size(
+        param_name, defined_type, default_value, validations_dict
+    )
     if not is_fixed_type(defined_type):
         code_gen_variable = CodeGenVariable(
             language, name, param_name, defined_type, default_value
@@ -789,7 +833,6 @@ def preprocess_inputs(language, name, value, nested_name_list):
     read_only = bool(value.get('read_only', False))
     validations = []
     additional_constraints = value.get('additional_constraints', '')
-    validations_dict = value.get('validation', {})
     if is_fixed_type(defined_type):
         validations_dict['size_lt<>'] = fixed_type_size(defined_type) + 1
 

generate_parameter_library_py/generate_parameter_library_py/test/YAML_parse_error_test.py

@@ -21,7 +21,10 @@
 from generate_parameter_library_py.generate_cpp_header import run as run_cpp
 from generate_parameter_library_py.generate_python_module import run as run_python
 from generate_parameter_library_py.generate_markdown import run as run_md
-from generate_parameter_library_py.parse_yaml import YAMLSyntaxError
+from generate_parameter_library_py.parse_yaml import (
+    YAMLSyntaxError,
+    preprocess_inputs,
+)
 from generate_parameter_library_py.generate_cpp_header import parse_args
 
 
@@ -100,3 +103,46 @@ def test_parse_valid_parameter_files(yaml_test_file):
         set_up(yaml_test_file)
     except Exception as e:
         assert False, f'failed to parse valid file, reason:{e}'
+
+
+@pytest.mark.parametrize(
+    'defined_type,default_value',
+    [
+        ('int_array_fixed_03', [101, 102, 103, 104]),
+        ('double_array_fixed_03', [1.0, 2.0, 3.0, 4.0]),
+        ('string_array_fixed_03', ['a', 'b', 'c', 'd']),
+        ('string_fixed_03', 'abcd'),
+    ],
+)
+def test_fixed_default_cannot_exceed_capacity(defined_type, default_value):
+    with pytest.raises(YAMLSyntaxError, match='exceeds the capacity'):
+        preprocess_inputs(
+            'cpp',
+            'test_param',
+            {'type': defined_type, 'default_value': default_value},
+            ['test_namespace'],
+        )
+
+
+def test_fixed_default_must_satisfy_fixed_size_validator():
+    with pytest.raises(YAMLSyntaxError, match="'fixed_size' validation requires 3"):
+        preprocess_inputs(
+            'cpp',
+            'test_param',
+            {
+                'type': 'int_array_fixed_03',
+                'default_value': [101, 102],
+                'validation': {'fixed_size<>': 3},
+            },
+            ['test_namespace'],
+        )
+
+
+@pytest.mark.parametrize('default_value', [[101, 102], [101, 102, 103]])
+def test_fixed_default_at_or_below_capacity_is_valid(default_value):
+    preprocess_inputs(
+        'cpp',
+        'test_param',
+        {'type': 'int_array_fixed_03', 'default_value': default_value},
+        ['test_namespace'],
+    )