Add implementation and tests

src/dependency_injector/providers.pyx

@@ -1140,6 +1140,15 @@ cdef class ConfigurationOption(Provider):
         root = self.__root_ref()
         return '.'.join((root.get_name(), self._get_self_name()))
 
+    def as_int(self):
+        return Callable(int, self)
+
+    def as_float(self):
+        return Callable(float, self)
+
+    def as_(self, callback, *args, **kwargs):
+        return Callable(callback, self, *args, **kwargs)
+
     def override(self, value):
         if isinstance(value, Provider):
             raise Error('Configuration option can only be overridden by a value')

tests/unit/providers/test_configuration_py2_py3.py

@@ -1,6 +1,7 @@
 """Dependency injector config providers unit tests."""
 
 import contextlib
+import decimal
 import os
 import sys
 import tempfile
@@ -69,6 +70,33 @@ class ConfigTests(unittest.TestCase):
         self.assertEqual(abc(), 1)
         self.assertEqual(abd(), 2)
 
+    def test_as_int(self):
+        value_provider = providers.Callable(lambda value: value, self.config.test.as_int())
+        self.config.from_dict({'test': '123'})
+
+        value = value_provider()
+
+        self.assertEqual(value, 123)
+
+    def test_as_float(self):
+        value_provider = providers.Callable(lambda value: value, self.config.test.as_float())
+        self.config.from_dict({'test': '123.123'})
+
+        value = value_provider()
+
+        self.assertEqual(value, 123.123)
+
+    def test_as_(self):
+        value_provider = providers.Callable(
+            lambda value: value,
+            self.config.test.as_(decimal.Decimal),
+        )
+        self.config.from_dict({'test': '123.123'})
+
+        value = value_provider()
+
+        self.assertEqual(value, decimal.Decimal('123.123'))
+
     def test_providers_value_override(self):
         a = self.config.a
         ab = self.config.a.b
@@ -358,7 +386,6 @@ class ConfigFromIniWithEnvInterpolationTests(unittest.TestCase):
         self.assertEqual(self.config.section1.value1(), 'test-value')
 
 
-
 class ConfigFromYamlTests(unittest.TestCase):
 
     def setUp(self):