From d0f32121f573a69084fdcbc8055d230b2cbca417 Mon Sep 17 00:00:00 2001
From: David Zwicker <david.zwicker@ds.mpg.de>
Date: Tue, 2 Jan 2024 16:25:08 +0100
Subject: [PATCH] Parameters can now be marked as required

Closes #6
---
 modelrunner/parameters.py | 16 +++++++++++++---
 tests/test_model.py       | 17 ++++++++++++++++-
 tests/test_parameters.py  | 11 +++++++++++
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/modelrunner/parameters.py b/modelrunner/parameters.py
index 1d94c60..6297733 100644
--- a/modelrunner/parameters.py
+++ b/modelrunner/parameters.py
@@ -81,12 +81,14 @@ class Parameter:
         name (str):
             The name of the parameter
         default_value:
-            The default value
+            The default value of the parameter
         cls:
             The type of the parameter, which is used for conversion
         description (str):
             A string describing the impact of this parameter. This
             description appears in the parameter help
+        required (bool):
+            Whther the parameter is required
         hidden (bool):
             Whether the parameter is hidden in the description summary
         extra (dict):
@@ -97,6 +99,7 @@ class Parameter:
     default_value: Any = None
     cls: Union[Type, Callable] = object
     description: str = ""
+    required: bool = False
     hidden: bool = False
     extra: Dict[str, Any] = field(default_factory=dict)
 
@@ -140,6 +143,7 @@ def __getstate__(self):
             "default_value": self.convert(),
             "cls": self.cls.__module__ + "." + self.cls.__name__,
             "description": self.description,
+            "required": self.required,
             "hidden": self.hidden,
             "extra": self.extra,
         }
@@ -202,7 +206,11 @@ def _argparser_add(self, parser):
                 description = f"Parameter `{self.name}`"
 
             arg_name = "--" + self.name
-            kwargs = {"default": self.default_value, "help": description}
+            kwargs = {
+                "required": self.required,
+                "default": self.default_value,
+                "help": description,
+            }
 
             if self.cls is bool:
                 # parameter is a boolean that we want to adjust
@@ -438,7 +446,7 @@ def _parse_parameters(
         allow_hidden: bool = True,
         include_deprecated: bool = False,
     ) -> Dict[str, Any]:
-        """parse parameters
+        """parse parameters from a given dictionary
 
         Args:
             parameters (dict):
@@ -470,6 +478,8 @@ def _parse_parameters(
         for name, param_obj in param_objs.items():
             if not allow_hidden and param_obj.hidden:
                 continue  # skip hidden parameters
+            if param_obj.required and name not in parameters:
+                raise ValueError(f"Require parameter `{name}`")
             # take value from parameters or set default value
             value = parameters.pop(name, NoValue)
             # convert parameter to correct type
diff --git a/tests/test_model.py b/tests/test_model.py
index 2ff9f65..5732153 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -101,7 +101,7 @@ def req_args_3(a=None):
     assert req_args_3() is None
 
 
-def test_required_arguments_model_class():
+def test_required_arguments_model_class_decorator():
     """test required arguments"""
 
     @make_model_class
@@ -127,6 +127,21 @@ def required_arg_3(a=None):
     assert required_arg_3()() is None
 
 
+def test_required_arguments_model_class():
+    """test required arguments"""
+
+    class A(ModelBase):
+        parameters_default = [Parameter("a", required=True), Parameter("b", 2)]
+
+        def __call__(self):
+            return self.parameters["a"] + self.parameters["b"]
+
+    assert A({"a": 3})() == 5
+    assert A.run_from_command_line(["--a", "3"]).data == 5
+    with pytest.raises(SystemExit):
+        A.run_from_command_line([])
+
+
 def test_make_model():
     """test the make_model decorator"""
 
diff --git a/tests/test_parameters.py b/tests/test_parameters.py
index 047d849..0b0e4f2 100644
--- a/tests/test_parameters.py
+++ b/tests/test_parameters.py
@@ -146,6 +146,17 @@ class TestHelp2(TestHelp1):
         assert e1 == e2 == ""
 
 
+def test_parameter_required():
+    """test required parameter"""
+
+    class TestRequired(Parameterized):
+        parameters_default = [Parameter("a", required=True)]
+
+    assert TestRequired({"a": 2}).parameters["a"] == 2
+    with pytest.raises(ValueError):
+        TestRequired()
+
+
 def test_hidden_parameter():
     """test how hidden parameters are handled"""