Add --used-fixtures command

pytest_deadfixtures.py

@@ -15,6 +15,10 @@
     "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 find any fixtures being used"
 
 EXIT_CODE_ERROR = 11
 EXIT_CODE_SUCCESS = 0
@@ -23,6 +27,8 @@
 
 CachedFixture = namedtuple("CachedFixture", "fixturedef, relpath, result")
 
+UsedFixture = namedtuple("UsedFixture", "relpath, argname, fixturedef")
+
 
 def pytest_addoption(parser):
     group = parser.getgroup("deadfixtures")
@@ -40,6 +46,13 @@ 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):
@@ -49,6 +62,10 @@ def pytest_cmdline_main(config):
         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):
@@ -57,6 +74,12 @@ def _show_dead_fixtures(config):
     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)
@@ -98,8 +121,10 @@ 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
@@ -113,8 +138,27 @@ 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):
@@ -198,13 +242,13 @@ def show_dead_fixtures(config, session):
     tw = _pytest.config.create_terminal_writer(config)
     show_fixture_doc = config.getvalue("show_fixture_doc")
 
-    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
+        if fixture.fixturedef not in used_fixturedefs
     ]
 
     tw.line()
@@ -214,3 +258,19 @@ 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

@@ -66,6 +66,11 @@ def test_simple():
 
     assert message not in result.stdout.str()
 
+    result = pytester.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(pytester, message_template):
     pytester.makepyfile(
@@ -90,6 +95,13 @@ def test_simple(same_file_fixture):
 
     assert message not in result.stdout.str()
 
+    result = pytester.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(pytester, message_template):
     pytester.makepyfile(
@@ -114,6 +126,13 @@ def test_simple():
 
     assert message in result.stdout.str()
 
+    result = pytester.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_list_same_file_multiple_unused_fixture(pytester, message_template):
     pytester.makepyfile(
@@ -176,6 +195,11 @@ def test_conftest_fixture(conftest_fixture):
 
     assert message not in result.stdout.str()
 
+    result = pytester.runpytest("--used-fixtures")
+    message = message_template.format("conftest_fixture", "conftest")
+
+    assert message in result.stdout.str()
+
 
 def test_list_conftest_unused_fixture(pytester, message_template):
     pytester.makepyfile(
@@ -204,6 +228,11 @@ def test_conftest_fixture():
 
     assert message in result.stdout.str()
 
+    result = pytester.runpytest("--used-fixtures")
+    message = message_template.format("conftest_fixture", "conftest")
+
+    assert message not in result.stdout.str()
+
 
 def test_list_conftest_multiple_unused_fixture(pytester, message_template):
     pytester.makepyfile(
@@ -266,6 +295,13 @@ def test_decorator_usefixtures():
 
     assert message not in result.stdout.str()
 
+    result = pytester.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(pytester):
     pytester.makepyfile(