Add --used-fixtures command

pytest_deadfixtures.py

@@ -13,6 +13,10 @@
 DUPLICATE_FIXTURES_HEADLINE = '\n\nYou may have some duplicate fixtures:'
 UNUSED_FIXTURES_FOUND_HEADLINE = 'Hey there, I believe the following fixture(s) are not being used:'
 UNUSED_FIXTURES_NOT_FOUND_HEADLINE = 'Cool, every declared fixture is being used.'
+USED_FIXTURES_FOUND_HEADLINE = (
+    'Hey there, I believe the following fixture(s) are being used:'
+)
+USED_FIXTURES_NOT_FOUND_HEADLINE = 'We could not any fixtures being used'
 
 EXIT_CODE_ERROR = 11
 EXIT_CODE_SUCCESS = 0
@@ -27,6 +31,11 @@
     'fixturedef, relpath, result'
 )
 
+UsedFixture = namedtuple(
+    'UsedFixture',
+    'relpath, argname, fixturedef'
+)
+
 
 def pytest_addoption(parser):
     group = parser.getgroup('deadfixtures')
@@ -44,20 +53,37 @@ def pytest_addoption(parser):
         default=False,
         help='Show duplicated fixtures'
     )
+    group.addoption(
+        '--used-fixtures',
+        action='store_true',
+        dest='usedfixtures',
+        default=False,
+        help='Show fixtures being used',
+    )
 
 
 def pytest_cmdline_main(config):
     if config.option.deadfixtures:
         if _show_dead_fixtures(config):
             return EXIT_CODE_ERROR
         return EXIT_CODE_SUCCESS
+    elif config.option.usedfixtures:
+        if _show_used_fixtures(config):
+            return EXIT_CODE_ERROR
+        return EXIT_CODE_SUCCESS
 
 
 def _show_dead_fixtures(config):
     from _pytest.main import wrap_session
     return wrap_session(config, show_dead_fixtures)
 
 
+def _show_used_fixtures(config):
+    from _pytest.main import wrap_session
+
+    return wrap_session(config, show_used_fixtures)
+
+
 def get_best_relpath(func, curdir):
     loc = getlocation(func, curdir)
     return curdir.bestrelpath(loc)
@@ -97,8 +123,10 @@ def get_fixtures(session):
     return available
 
 
-def get_used_fixturesdefs(session):
-    fixturesdefs = []
+def get_used_fixtures(session):
+    used = []
+    seen = set()
+    curdir = py.path.local()
     for test_function in session.items:
         try:
             info = test_function._fixtureinfo
@@ -112,8 +140,27 @@ def get_used_fixturesdefs(session):
         for _, fixturedefs in sorted(info.name2fixturedefs.items()):
             if fixturedefs is None:
                 continue
-            fixturesdefs.append(fixturedefs[-1])
-    return fixturesdefs
+
+            for fixturedef in fixturedefs:
+                loc = getlocation(fixturedef.func, curdir)
+                if (fixturedef.argname, loc) in seen:
+                    continue
+
+                seen.add((fixturedef.argname, loc))
+
+                module = fixturedef.func.__module__
+
+                if (
+                    not module.startswith("_pytest.") and
+                    not module.startswith("pytest_") and
+                    not ('site-packages' in loc)
+                ):
+                    used.append(
+                        UsedFixture(
+                            curdir.bestrelpath(loc), fixturedef.argname, fixturedef
+                        )
+                    )
+    return used
 
 
 def write_docstring(tw, doc):
@@ -201,11 +248,14 @@ def show_dead_fixtures(config, session):
     tw = _pytest.config.create_terminal_writer(config)
     verbose = config.getvalue('verbose')
 
-    used_fixtures = get_used_fixturesdefs(session)
+    used_fixturedefs = [f.fixturedef for f in get_used_fixtures(session)]
     available_fixtures = get_fixtures(session)
 
-    unused_fixtures = [fixture for fixture in available_fixtures
-                       if fixture.fixturedef not in used_fixtures]
+    unused_fixtures = [
+        fixture
+        for fixture in available_fixtures
+        if fixture.fixturedef not in used_fixturedefs
+    ]
 
     tw.line()
     if unused_fixtures:
@@ -214,3 +264,19 @@ def show_dead_fixtures(config, session):
     else:
         tw.line(UNUSED_FIXTURES_NOT_FOUND_HEADLINE, green=True)
     return unused_fixtures
+
+
+def show_used_fixtures(config, session):
+    session.perform_collect()
+    tw = _pytest.config.create_terminal_writer(config)
+    verbose = config.getvalue('verbose')
+
+    used_fixtures = get_used_fixtures(session)
+
+    tw.line()
+    if used_fixtures:
+        tw.line(USED_FIXTURES_FOUND_HEADLINE, green=True)
+        write_fixtures(tw, used_fixtures, verbose)
+    else:
+        tw.line(USED_FIXTURES_NOT_FOUND_HEADLINE, red=True)
+    return used_fixtures

tests/test_deadfixtures.py

@@ -61,6 +61,14 @@ def test_simple():
 
     assert message not in result.stdout.str()
 
+    result = testdir.runpytest('--used-fixtures')
+    message = message_template.format(
+        'autouse_fixture',
+        'test_dont_list_autouse_fixture'
+    )
+
+    assert message in result.stdout.str()
+
 
 def test_dont_list_same_file_fixture(testdir, message_template):
     testdir.makepyfile("""
@@ -84,6 +92,14 @@ def test_simple(same_file_fixture):
 
     assert message not in result.stdout.str()
 
+    result = testdir.runpytest('--used-fixtures')
+    message = message_template.format(
+        'same_file_fixture',
+        'test_dont_list_same_file_fixture'
+    )
+
+    assert message in result.stdout.str()
+
 
 def test_list_same_file_unused_fixture(testdir, message_template):
     testdir.makepyfile("""
@@ -107,6 +123,14 @@ def test_simple():
 
     assert message in result.stdout.str()
 
+    result = testdir.runpytest('--used-fixtures')
+    message = message_template.format(
+        'same_file_fixture',
+        'test_list_same_file_unused_fixture'
+    )
+
+    assert message not in result.stdout.str()
+
 
 def test_dont_list_conftest_fixture(testdir, message_template):
     testdir.makepyfile(conftest="""
@@ -134,6 +158,14 @@ def test_conftest_fixture(conftest_fixture):
 
     assert message not in result.stdout.str()
 
+    result = testdir.runpytest('--used-fixtures')
+    message = message_template.format(
+        'conftest_fixture',
+        'conftest'
+    )
+
+    assert message in result.stdout.str()
+
 
 def test_list_conftest_unused_fixture(testdir, message_template):
     testdir.makepyfile(conftest="""
@@ -161,6 +193,14 @@ def test_conftest_fixture():
 
     assert message in result.stdout.str()
 
+    result = testdir.runpytest('--used-fixtures')
+    message = message_template.format(
+        'conftest_fixture',
+        'conftest'
+    )
+
+    assert message not in result.stdout.str()
+
 
 def test_dont_list_decorator_usefixtures(testdir, message_template):
     testdir.makepyfile("""
@@ -185,6 +225,14 @@ def test_decorator_usefixtures():
 
     assert message not in result.stdout.str()
 
+    result = testdir.runpytest('--used-fixtures')
+    message = message_template.format(
+        'decorator_usefixtures',
+        'test_dont_list_decorator_usefixtures'
+    )
+
+    assert message in result.stdout.str()
+
 
 def test_write_docs_when_verbose(testdir):
     testdir.makepyfile("""