Merge pull request #111 from druids/FixUtilHelpers

Fixed class method utils

chamber/utils/__init__.py

@@ -10,6 +10,10 @@
 from django.utils.text import normalize_newlines
 
 
+class InvalidFunctionArguments(Exception):
+    pass
+
+
 def remove_accent(string_with_diacritics):
     """
     Removes a diacritics from a given string"
@@ -28,7 +32,7 @@ def get_class_method(cls_or_inst, method_name):
         meth = meth.fget
     elif isinstance(meth, cached_property):
         meth = meth.func
-    return meth
+    return meth if callable(meth) else None
 
 
 def keep_spacing(value, autoescape=True):
@@ -43,15 +47,28 @@ def keep_spacing(value, autoescape=True):
     return mark_safe(value.replace('  ', ' &nbsp;').replace('\n', '<br />'))
 
 
-def call_method_with_unknown_input(method, **fun_kwargs):
-    method_kwargs_names = inspect.getargspec(method)[0][1:]
+def call_function_with_unknown_input(function, **kwargs):
+    """
+    Call function and use kwargs from input if function requires them.
+    :param function: function to call.
+    :param kwargs: function input kwargs or extra kwargs which will not be used.
+    :return: function result or raised InvalidFunctionArguments exception.
+    """
+    function_kwargs_names = set(inspect.signature(function).parameters.keys())
 
-    method_kwargs = {arg_name: fun_kwargs[arg_name] for arg_name in method_kwargs_names if arg_name in fun_kwargs}
+    required_function_kwargs_names = set(
+        k for k, v in inspect.signature(function).parameters.items() if v.default is v.empty
+    )
 
-    if len(method_kwargs_names) == len(method_kwargs):
-        return method(**method_kwargs)
+    function_kwargs = {k: v for k, v in kwargs.items() if k in function_kwargs_names}
+    if required_function_kwargs_names <= set(function_kwargs.keys()):
+        return function(**function_kwargs)
     else:
-        raise RuntimeError('Invalid method parameters')
+        raise InvalidFunctionArguments(
+            'Function {} missing required arguments {}'.format(
+                function, ', '.join(required_function_kwargs_names - set(function_kwargs.keys()))
+            )
+        )
 
 
 def generate_container_app_config(name,):

example/Makefile

@@ -13,7 +13,7 @@ SETTINGS = settings
 DJANGO_SETTINGS_MODULE = $(DJANGO_DIR).settings.$(SETTINGS)
 DJANGO_POSTFIX = --settings=$(DJANGO_SETTINGS_MODULE) --pythonpath=$(PYTHONPATH)
 PYTHON_BIN = $(VIRTUAL_ENV)/bin
-PYTHON = python3.7
+PYTHON = python3
 PYTHON_VERSION_FULL := $(wordlist 2,4,$(subst ., ,$(shell python --version 2>&1)))
 PYTHON_VERSION_MAJOR := $(word 1,${PYTHON_VERSION_FULL}).$(word 2,${PYTHON_VERSION_FULL})
 TYPE = dev
@@ -40,8 +40,7 @@ pip:
 	$(PYTHON_BIN)/pip install -r requirements.txt
 
 initvirtualenv:
-	virtualenv -p $(PYTHON) --no-site-packages $(VIRTUAL_ENV)
-	$(PYTHON_BIN)/pip install setuptools --upgrade
+	virtualenv -p $(PYTHON) $(VIRTUAL_ENV)
 
 bootstrap: initvirtualenv pip
 

example/dj/apps/test_chamber/tests/utils/__init__.py

@@ -3,8 +3,11 @@
 from django.test import TestCase
 from django.utils.functional import cached_property
 from django.utils.safestring import SafeData, mark_safe
+from django.utils.functional import cached_property
 
-from chamber.utils import get_class_method, keep_spacing, remove_accent
+from chamber.utils import (
+    get_class_method, keep_spacing, remove_accent, call_function_with_unknown_input, InvalidFunctionArguments
+)
 
 from germanium.decorators import data_provider  # pylint: disable=E0401
 from germanium.tools import assert_equal, assert_true  # pylint: disable=E0401
@@ -26,6 +29,8 @@ def property_method(self):
     def cached_property_method(self):
         pass
 
+    attribute = 'attribute'
+
 
 class UtilsTestCase(TestCase):
 
@@ -49,10 +54,14 @@ def test_should_remove_accent_from_string_when_unicode_error(self):
         [TestClass.property_method.fget, TestClass(), 'property_method'],
         [TestClass.cached_property_method.func, TestClass, 'cached_property_method'],
         [TestClass.cached_property_method.func, TestClass(), 'cached_property_method'],
+        [None, TestClass, 'attribute'],
+        [None, TestClass(), 'attribute'],
+        [None, TestClass, 'invalid'],
+        [None, TestClass(), 'invalid'],
     ]
 
     @data_provider(classes_and_method_names)
-    def test_should_return_class_method(self, expected_method, cls_or_inst, method_name):
+    def test_get_class_method_should_return_right_class_method_or_none(self, expected_method, cls_or_inst, method_name):
         assert_equal(expected_method, get_class_method(cls_or_inst, method_name))
 
     values_for_keep_spacing = [
@@ -68,3 +77,27 @@ def test_should_keep_spacing(self, expected, value, autoescape):
         escaped_value = keep_spacing(value, autoescape)
         assert_equal(expected, escaped_value)
         assert_true(isinstance(escaped_value, SafeData))
+
+    def test_call_function_with_unknown_input_should_return_right_response_or_exception(self):
+        def test_function(a, b, c):
+            assert_equal(a, 3)
+            assert_equal(b, 2)
+            assert_equal(c, 1)
+
+        call_function_with_unknown_input(test_function, a=3, b=2, c=1)
+        call_function_with_unknown_input(test_function, c=1, a=3, b=2)
+        call_function_with_unknown_input(test_function, c=1, a=3, b=2, d=8, e=9)
+
+        with assert_raises(InvalidFunctionArguments):
+            call_function_with_unknown_input(test_function, a=3, b=2)
+
+    def test_call_function_with_default_values_and_unknown_input_should_return_right_response_or_exception(self):
+        def test_function(a, b=5, c=6):
+            return a, b, c
+
+        assert_equal(call_function_with_unknown_input(test_function, a=1), (1, 5, 6))
+        assert_equal(call_function_with_unknown_input(test_function, c=1, a=2), (2, 5, 1))
+        assert_equal(call_function_with_unknown_input(test_function, b=1, a=2), (2, 1, 6))
+
+        with assert_raises(InvalidFunctionArguments):
+            call_function_with_unknown_input(test_function, b=2, c=1)