Allow custom fixture names for fixtures

When defining a fixture in the same module as where it is used, the
function argument shadows the fixture name, which a) annoys pylint and
b) can lead to bugs where you forget to request a fixture into a test
method.

This allows one to define fixtures with a different name than the name
of the function, bypassing that problem.

AUTHORS

@@ -63,6 +63,7 @@ Matt Williams
 Michael Aquilina
 Michael Birtwell
 Michael Droettboom
+Mike Lundy
 Nicolas Delaby
 Pieter Mulder
 Piotr Banaszkiewicz

CHANGELOG.rst

@@ -7,6 +7,10 @@
   namespace in which your doctests run.
   Thanks `@milliams`_ for the complete PR (`#1428`_).
 
+* New ``name`` argument to ``pytest.fixture`` mark, which allows a custom name
+  for a fixture (to solve the funcarg-shadowing-fixture problem).
+  Thanks `@novas0x2a`_ for the complete PR (`#1444`_).
+
 *
 
 *
@@ -21,8 +25,10 @@
 *
 
 .. _@milliams: https://github.com/milliams
+.. _@novas0x2a: https://github.com/novas0x2a
 
 .. _#1428: https://github.com/pytest-dev/pytest/pull/1428
+.. _#1444: https://github.com/pytest-dev/pytest/pull/1444
 
 
 2.9.1.dev1

_pytest/python.py

@@ -114,12 +114,13 @@ def safe_getattr(object, name, default):
 
 class FixtureFunctionMarker:
     def __init__(self, scope, params,
-                 autouse=False, yieldctx=False, ids=None):
+                 autouse=False, yieldctx=False, ids=None, name=None):
         self.scope = scope
         self.params = params
         self.autouse = autouse
         self.yieldctx = yieldctx
         self.ids = ids
+        self.name = name
 
     def __call__(self, function):
         if isclass(function):
@@ -129,7 +130,7 @@ class FixtureFunctionMarker:
         return function
 
 
-def fixture(scope="function", params=None, autouse=False, ids=None):
+def fixture(scope="function", params=None, autouse=False, ids=None, name=None):
     """ (return a) decorator to mark a fixture factory function.
 
     This decorator can be used (with or or without parameters) to define
@@ -155,14 +156,21 @@ def fixture(scope="function", params=None, autouse=False, ids=None):
        so that they are part of the test id. If no ids are provided
        they will be generated automatically from the params.
 
+    :arg name: the name of the fixture. This defaults to the name of the
+               decorated function. If a fixture is used in the same module in
+               which it is defined, the function name of the fixture will be
+               shadowed by the function arg that requests the fixture; one way
+               to resolve this is to name the decorated function
+               ``fixture_<fixturename>`` and then use
+               ``@pytest.fixture(name='<fixturename>')``.
     """
     if callable(scope) and params is None and autouse == False:
         # direct decoration
         return FixtureFunctionMarker(
-                "function", params, autouse)(scope)
+                "function", params, autouse, name=name)(scope)
     if params is not None and not isinstance(params, (list, tuple)):
         params = list(params)
-    return FixtureFunctionMarker(scope, params, autouse, ids=ids)
+    return FixtureFunctionMarker(scope, params, autouse, ids=ids, name=name)
 
 def yield_fixture(scope="function", params=None, autouse=False, ids=None):
     """ (return a) decorator to mark a yield-fixture factory function
@@ -1989,6 +1997,8 @@ class FixtureManager:
                 # fixture attribute
                 continue
             else:
+                if marker.name:
+                    name = marker.name
                 assert not name.startswith(self._argprefix)
             fixturedef = FixtureDef(self, nodeid, name, obj,
                                     marker.scope, marker.params,

testing/python/fixture.py

@@ -2691,3 +2691,14 @@ class TestContextManagerFixtureFuncs:
             *def arg1*
         """)
 
+    def test_custom_name(self, testdir):
+        testdir.makepyfile("""
+            import pytest
+            @pytest.fixture(name='meow')
+            def arg1():
+                return 'mew'
+            def test_1(meow):
+                print(meow)
+        """)
+        result = testdir.runpytest("-s")
+        result.stdout.fnmatch_lines("*mew*")