feat(defaults): add overrides support (#25)

Close #25

rebulk/builder.py

@@ -4,6 +4,7 @@
 Base builder class for Rebulk
 """
 from abc import ABCMeta, abstractmethod
+from contextlib import contextmanager
 from copy import deepcopy
 from logging import getLogger
 
@@ -13,6 +14,24 @@
 log = getLogger(__name__).log
 
 
+@contextmanager
+def overrides(kwargs):
+    """
+    Implements override kwarg to restore initial kwarg arguments from overrides list after set_defaults calls.
+    :param kwargs:
+    :return:
+    """
+    override_keys = kwargs.pop('overrides', None)
+    backup = {}
+    if override_keys:
+        for override_key in override_keys:
+            backup[override_key] = kwargs[override_key]
+
+    yield backup
+
+    kwargs.update(backup)
+
+
 class Builder(metaclass=ABCMeta):
     """
     Base builder class for patterns
@@ -99,8 +118,10 @@ def build_re(self, *pattern, **kwargs):
         :return:
         :rtype:
         """
-        set_defaults(self._regex_defaults, kwargs)
-        set_defaults(self._defaults, kwargs)
+        with overrides(kwargs):
+            set_defaults(self._regex_defaults, kwargs)
+            set_defaults(self._defaults, kwargs)
+
         return RePattern(*pattern, **kwargs)
 
     def build_string(self, *pattern, **kwargs):
@@ -114,8 +135,10 @@ def build_string(self, *pattern, **kwargs):
         :return:
         :rtype:
         """
-        set_defaults(self._string_defaults, kwargs)
-        set_defaults(self._defaults, kwargs)
+        with overrides(kwargs):
+            set_defaults(self._string_defaults, kwargs)
+            set_defaults(self._defaults, kwargs)
+
         return StringPattern(*pattern, **kwargs)
 
     def build_functional(self, *pattern, **kwargs):
@@ -129,8 +152,10 @@ def build_functional(self, *pattern, **kwargs):
         :return:
         :rtype:
         """
-        set_defaults(self._functional_defaults, kwargs)
-        set_defaults(self._defaults, kwargs)
+        with overrides(kwargs):
+            set_defaults(self._functional_defaults, kwargs)
+            set_defaults(self._defaults, kwargs)
+
         return FunctionalPattern(*pattern, **kwargs)
 
     def build_chain(self, **kwargs):
@@ -145,14 +170,18 @@ def build_chain(self, **kwargs):
         :rtype:
         """
         from .chain import Chain  # pylint:disable=import-outside-toplevel
-        set_defaults(self._chain_defaults, kwargs)
-        set_defaults(self._defaults, kwargs)
+
+        with overrides(kwargs):
+            set_defaults(self._chain_defaults, kwargs)
+            set_defaults(self._defaults, kwargs)
+
         chain = Chain(self, **kwargs)
         chain._defaults = deepcopy(self._defaults)  # pylint: disable=protected-access
         chain._regex_defaults = deepcopy(self._regex_defaults)  # pylint: disable=protected-access
         chain._functional_defaults = deepcopy(self._functional_defaults)  # pylint: disable=protected-access
         chain._string_defaults = deepcopy(self._string_defaults)  # pylint: disable=protected-access
         chain._chain_defaults = deepcopy(self._chain_defaults)  # pylint: disable=protected-access
+
         return chain
 
     @abstractmethod

rebulk/test/test_rebulk.py

@@ -120,6 +120,44 @@ def func(input_string):
     assert matches[2].tags == ["0"]
 
 
+def test_rebulk_defaults_overrides():
+    input_string = "The quick brown fox jumps over the lazy dog"
+
+    def func(input_string):
+        i = input_string.find("fox")
+        if i > -1:
+            return i, i + len("fox")
+
+    matches = Rebulk() \
+        .string_defaults(name="string", tags=["a", "b"]) \
+        .regex_defaults(name="regex", tags=["d"]) \
+        .functional_defaults(name="functional") \
+        .string("quick", tags=["c"], overrides=["tags"]) \
+        .functional(func) \
+        .regex("br.{2}n") \
+        .matches(input_string)
+    assert matches[0].name == "string"
+    assert matches[0].tags == ["c"]
+    assert matches[1].name == "functional"
+    assert matches[2].name == "regex"
+    assert matches[2].tags == ["d"]
+
+    matches = Rebulk() \
+        .defaults(name="default", tags=["0"]) \
+        .string_defaults(name="string", tags=["a", "b"]) \
+        .functional_defaults(name="functional", tags=["1"]) \
+        .string("quick", tags=["c"]) \
+        .functional(func) \
+        .regex("br.{2}n") \
+        .matches(input_string)
+    assert matches[0].name == "string"
+    assert matches[0].tags == ["0", "a", "b", "c"]
+    assert matches[1].name == "functional"
+    assert matches[1].tags == ["0", "1"]
+    assert matches[2].name == "default"
+    assert matches[2].tags == ["0"]
+
+
 def test_rebulk_rebulk():
     input_string = "The quick brown fox jumps over the lazy dog"