Add unwrap feature to Result object. Add cache for pip requirements i…

…n github action. Add pre-commit config file

.github/workflows/ci.yml

@@ -24,6 +24,12 @@ jobs:
       uses: actions/setup-python@v1
       with:
         python-version: ${{ matrix.python-version }}
+    - uses: actions/cache@v1
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('**/ci.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

README.md

@@ -184,6 +184,20 @@ class AuthService:
         return NotImplementedMethodError
 ```
 
+### Unwrap Result
+
+If you *wrap* a Result object, its will return a valid value if it is success. Otherwise, it will return None.
+
+```python
+result = Result(success="Hi!")
+value = result.unwrap()
+assert value == "Hi!"
+
+result = Failure(Error())
+value = result.unwrap()
+
+assert value is None
+```
 
 ### Handle Result
 

meiga/result.py

@@ -61,6 +61,12 @@ def is_success(self):
     def is_failure(self):
         return not self._is_success
 
+    def unwrap(self):
+        if not self._is_success:
+            return None
+        else:
+            return self._value_success
+
     def handle(
         self,
         success_handler: Callable = None,

tests/unit/test_result_unwrap.py

@@ -0,0 +1,21 @@
+import pytest
+
+from meiga import Result, Error, Failure
+
+
+@pytest.mark.unit
+def test_should_return_the_value_when_unwrap_a_success_result():
+
+    result = Result(success="Hi!")
+    value = result.unwrap()
+
+    assert value == "Hi!"
+
+
+@pytest.mark.unit
+def test_should_return_none_when_unwrap_a_failure_result():
+
+    result = Failure(Error())
+    value = result.unwrap()
+
+    assert value is None