update recap sidebar

Author: hjwp

chapter_19_mocking.asciidoc

@@ -2169,48 +2169,52 @@ In the meantime, do a commit and enjoy this recap:
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 Mocking and external dependencies::
-    ((("external dependencies")))We
-    use mocking in unit tests when we have an external dependency that we
-    don't want to actually use in our tests.  A mock is used to simulate the
-    third-party API.   Whilst it is possible to "roll your own" mocks in
-    Python, a mocking framework like the +mock+ module provides a lot of helpful
-    shortcuts which will make it easier to write (and more importantly, read)
-    your tests.
+    We use mocking in unit tests when we have an external dependency
+    that we don't want to actually use in our tests.
+    A mock is used to simulate the third-party API.
+    Whilst it is possible to "roll your own" mocks in Python,
+    a mocking framework like the +unittest.mock+ module provides a lot of helpful shortcuts
+    which will make it easier to write (and more importantly, read) your tests.
+    ((("external dependencies")))
 
 
 Monkeypatching::
-    ((("monkeypatching")))Replacing
-    an object in a namespace at runtime.  We use it in our unit
-    tests to replace a real function which has undesirable side effects with a
-    mock object, using the `patch` decorator.
+    Replacing an object in a namespace at runtime.
+    We use it in our unit tests to replace a real function
+    which has undesirable side effects
+    with a mock object, using the `mock.patch` decorator.
+    ((("monkeypatching")))
 
 
 The Mock library::
-    ((("mocks", "Python Mock library")))((("Python 3", "Mock library")))Michael
-    Foord (who used to work for the company that spawned
-    PythonAnywhere, just before I joined) wrote the excellent "Mock"
-    library that's now been integrated into the standard library of Python 3.
+    Michael Foord (who used to work for the company that spawned PythonAnywhere,
+    just before I joined) wrote the excellent "Mock" library
+    that's now been integrated into the standard library of Python 3.
     It contains most everything you might need for mocking in Python.
+    ((("mocks", "Python Mock library")))
+    ((("Python 3", "Mock library")))
 
 
-The patch decorator::
-    `unittest.mock` ((("patch decorator")))provides
-    a function called `patch`, which can be used
-    to "mock out" any object from the module you're testing.  It's commonly
-    used as a decorator on a test method, or even at the class level, where
-    it's applied to all the test methods of that class.
+The mock.patch decorator::
+    `unittest.mock` ((("patch decorator")))provides a function called `patch`,
+    which can be used to "mock out" (monkeypatch)
+    any object from the module you're testing.
+    It's commonly used as a decorator on a test method.
+    Importantly, it "undoes" the mocking at the end of the test for you,
+    to avoid contamination between tests.
 
 
 Mocks can leave you tightly coupled to the implementation::
     As we saw in <<mocks-tightly-coupled-sidebar>>,
-    mocks can leave you tightly coupled to your implementation. For that
-    reason, you shouldn't use them unless you have a good reason.
+    mocks can leave you tightly coupled to your implementation.
+    For that reason, you shouldn't use them unless you have a good reason.
 
 Mocks can save you from duplication in your tests::
-    ((("mocks", "reducing duplication with")))((("duplication, eliminating")))On
-    the other hand, there's no point in duplicating all of your tests
-    for a function inside a higher-level piece of code that uses that
-    function.  Using a mock in this case reduces duplication.
+    With that said, there is an argument for using mocks to remove duplication;
+    used extensively, this approach leads to "London-style" TDD,
+    a variation on the style I mostly follow and show in this book.
+    ((("mocks", "reducing duplication with")))
+    ((("duplication, eliminating")))
 
 There's lots more discussion of the pros and cons of mocks
 <<chapter_purist_unit_tests,coming up soon>>.  Read on!