DRYing up the test suite using pytest fixtures (#2306)

* add fixtures to conftest.py

* use fixtures in test_appctx.py

* use fixtures in test_blueprints.py

* use fixtures in test_depreciations.py

* use fixtures in test_regressions.py

* use fixtures in test_reqctx.py

* use fixtures in test_templating.py

* use fixtures in test_user_error_handler.py

* use fixtures in test_views.py

* use fixtures in test_basics.py

* use fixtures in test_helpers.py

* use fixtures in test_testing.py

* update conftest.py

* make docstrings  PEP-257 compliant

* cleanup

* switch dictonary format

* use pytest parameterization for test_json_as_unicode

tests/conftest.py

@@ -13,6 +13,40 @@ import sys
 import pkgutil
 import pytest
 import textwrap
+from flask import Flask as _Flask
+
+
+class Flask(_Flask):
+    testing = True
+    secret_key = __name__
+
+    def make_response(self, rv):
+        if rv is None:
+            rv = ''
+        return super(Flask, self).make_response(rv)
+
+
+@pytest.fixture
+def app():
+    app = Flask(__name__)
+    return app
+
+
+@pytest.fixture
+def app_ctx(app):
+    with app.app_context() as ctx:
+        yield ctx
+
+
+@pytest.fixture
+def req_ctx(app):
+    with app.test_request_context() as ctx:
+        yield ctx
+
+
+@pytest.fixture
+def client(app):
+    return app.test_client()
 
 
 @pytest.fixture
@@ -63,12 +97,13 @@ def limit_loader(request, monkeypatch):
 
     def get_loader(*args, **kwargs):
         return LimitedLoader(old_get_loader(*args, **kwargs))
+
     monkeypatch.setattr(pkgutil, 'get_loader', get_loader)
 
 
 @pytest.fixture
 def modules_tmpdir(tmpdir, monkeypatch):
-    '''A tmpdir added to sys.path'''
+    """A tmpdir added to sys.path."""
     rv = tmpdir.mkdir('modules_tmpdir')
     monkeypatch.syspath_prepend(str(rv))
     return rv
@@ -82,10 +117,10 @@ def modules_tmpdir_prefix(modules_tmpdir, monkeypatch):
 
 @pytest.fixture
 def site_packages(modules_tmpdir, monkeypatch):
-    '''Create a fake site-packages'''
+    """Create a fake site-packages."""
     rv = modules_tmpdir \
-        .mkdir('lib')\
-        .mkdir('python{x[0]}.{x[1]}'.format(x=sys.version_info))\
+        .mkdir('lib') \
+        .mkdir('python{x[0]}.{x[1]}'.format(x=sys.version_info)) \
         .mkdir('site-packages')
     monkeypatch.syspath_prepend(str(rv))
     return rv
@@ -93,8 +128,9 @@ def site_packages(modules_tmpdir, monkeypatch):
 
 @pytest.fixture
 def install_egg(modules_tmpdir, monkeypatch):
-    '''Generate egg from package name inside base and put the egg into
-    sys.path'''
+    """Generate egg from package name inside base and put the egg into
+    sys.path."""
+
     def inner(name, base=modules_tmpdir):
         if not isinstance(name, str):
             raise ValueError(name)
@@ -118,6 +154,7 @@ def install_egg(modules_tmpdir, monkeypatch):
         egg_path, = modules_tmpdir.join('dist/').listdir()
         monkeypatch.syspath_prepend(str(egg_path))
         return egg_path
+
     return inner
 
 
@@ -125,6 +162,7 @@ def install_egg(modules_tmpdir, monkeypatch):
 def purge_module(request):
     def inner(name):
         request.addfinalizer(lambda: sys.modules.pop(name, None))
+
     return inner
 
 
@@ -132,4 +170,4 @@ def purge_module(request):
 def catch_deprecation_warnings(recwarn):
     yield
     gc.collect()
-    assert not recwarn.list
+    assert not recwarn.list, '\n'.join(str(w.message) for w in recwarn.list)