Merge pull request #1606 from hackebrot/show-fixtures-per-test

Show fixtures per test

CHANGELOG.rst

@@ -34,6 +34,11 @@
 * New ``pytest_make_parametrize_id`` hook.
   Thanks `@palaviv`_ for the PR.
 
+* New cli flag ``--fixtures-per-test`` that shows which fixtures are being used
+  for each selected test item. Features doc strings of fixtures by default.
+  Can also show where fixtures are defined if combined with ``-v``.
+  Thanks `@hackebrot`_ for the PR.
+
 **Changes**
 
 * Fixtures marked with ``@pytest.fixture`` can now use ``yield`` statements exactly like

_pytest/python.py

@@ -208,6 +208,13 @@ def pytest_addoption(parser):
     group.addoption('--fixtures', '--funcargs',
                action="store_true", dest="showfixtures", default=False,
                help="show available fixtures, sorted by plugin appearance")
+    group.addoption(
+        '--fixtures-per-test',
+        action="store_true",
+        dest="show_fixtures_per_test",
+        default=False,
+        help="show fixtures per test",
+    )
     parser.addini("usefixtures", type="args", default=[],
         help="list of default fixtures to be used with this project")
     parser.addini("python_files", type="args",
@@ -229,6 +236,9 @@ def pytest_cmdline_main(config):
     if config.option.showfixtures:
         showfixtures(config)
         return 0
+    if config.option.show_fixtures_per_test:
+        show_fixtures_per_test(config)
+        return 0
 
 
 def pytest_generate_tests(metafunc):
@@ -1194,6 +1204,67 @@ def idmaker(argnames, argvalues, idfn=None, ids=None, config=None):
                 counters[testid] += 1
     return ids
 
+
+def show_fixtures_per_test(config):
+    from _pytest.main import wrap_session
+    return wrap_session(config, _show_fixtures_per_test)
+
+
+def _show_fixtures_per_test(config, session):
+    import _pytest.config
+    session.perform_collect()
+    curdir = py.path.local()
+    tw = _pytest.config.create_terminal_writer(config)
+    verbose = config.getvalue("verbose")
+
+    def get_best_rel(func):
+        loc = getlocation(func, curdir)
+        return curdir.bestrelpath(loc)
+
+    def write_fixture(fixture_def):
+        argname = fixture_def.argname
+
+        if verbose <= 0 and argname.startswith("_"):
+            return
+        if verbose > 0:
+            bestrel = get_best_rel(fixture_def.func)
+            funcargspec = "{0} -- {1}".format(argname, bestrel)
+        else:
+            funcargspec = argname
+        tw.line(funcargspec, green=True)
+
+        INDENT = '    {0}'
+        fixture_doc = fixture_def.func.__doc__
+
+        if fixture_doc:
+            for line in fixture_doc.strip().split('\n'):
+                tw.line(INDENT.format(line.strip()))
+        else:
+            tw.line(INDENT.format('no docstring available'), red=True)
+
+    def write_item(item):
+        name2fixturedefs = item._fixtureinfo.name2fixturedefs
+
+        if not name2fixturedefs:
+            # The given test item does not use any fixtures
+            return
+        bestrel = get_best_rel(item.function)
+
+        tw.line()
+        tw.sep('-', 'fixtures used by {0}'.format(item.name))
+        tw.sep('-', '({0})'.format(bestrel))
+        for argname, fixture_defs in sorted(name2fixturedefs.items()):
+            assert fixture_defs is not None
+            if not fixture_defs:
+                continue
+            # The last fixture def item in the list is expected
+            # to be the one used by the test item
+            write_fixture(fixture_defs[-1])
+
+    for item in session.items:
+        write_item(item)
+
+
 def showfixtures(config):
     from _pytest.main import wrap_session
     return wrap_session(config, _showfixtures_main)

testing/python/show_fixtures_per_test.py

@@ -0,0 +1,137 @@
+# -*- coding: utf-8 -*-
+
+
+def test_no_items_should_not_show_output(testdir):
+    result = testdir.runpytest('--fixtures-per-test')
+    assert 'fixtures used by' not in result.stdout.str()
+    assert result.ret == 0
+
+
+def test_fixtures_in_module(testdir):
+    p = testdir.makepyfile('''
+        import pytest
+        @pytest.fixture
+        def _arg0():
+            """hidden arg0 fixture"""
+        @pytest.fixture
+        def arg1():
+            """arg1 docstring"""
+        def test_arg1(arg1):
+            pass
+    ''')
+
+    result = testdir.runpytest("--fixtures-per-test", p)
+    assert result.ret == 0
+
+    result.stdout.fnmatch_lines([
+        '*fixtures used by test_arg1*',
+        '*(test_fixtures_in_module.py:9)*',
+        'arg1',
+        '    arg1 docstring',
+    ])
+    assert "_arg0" not in result.stdout.str()
+
+
+def test_fixtures_in_conftest(testdir):
+    testdir.makeconftest('''
+        import pytest
+        @pytest.fixture
+        def arg1():
+            """arg1 docstring"""
+        @pytest.fixture
+        def arg2():
+            """arg2 docstring"""
+        @pytest.fixture
+        def arg3(arg1, arg2):
+            """arg3
+            docstring
+            """
+    ''')
+    p = testdir.makepyfile('''
+        def test_arg2(arg2):
+            pass
+        def test_arg3(arg3):
+            pass
+    ''')
+    result = testdir.runpytest("--fixtures-per-test", p)
+    assert result.ret == 0
+
+    result.stdout.fnmatch_lines([
+        '*fixtures used by test_arg2*',
+        '*(test_fixtures_in_conftest.py:2)*',
+        'arg2',
+        '    arg2 docstring',
+        '*fixtures used by test_arg3*',
+        '*(test_fixtures_in_conftest.py:4)*',
+        'arg1',
+        '    arg1 docstring',
+        'arg2',
+        '    arg2 docstring',
+        'arg3',
+        '    arg3',
+        '    docstring',
+    ])
+
+
+def test_should_show_fixtures_used_by_test(testdir):
+    testdir.makeconftest('''
+        import pytest
+        @pytest.fixture
+        def arg1():
+            """arg1 from conftest"""
+        @pytest.fixture
+        def arg2():
+            """arg2 from conftest"""
+    ''')
+    p = testdir.makepyfile('''
+        import pytest
+        @pytest.fixture
+        def arg1():
+            """arg1 from testmodule"""
+        def test_args(arg1, arg2):
+            pass
+    ''')
+    result = testdir.runpytest("--fixtures-per-test", p)
+    assert result.ret == 0
+
+    result.stdout.fnmatch_lines([
+        '*fixtures used by test_args*',
+        '*(test_should_show_fixtures_used_by_test.py:6)*',
+        'arg1',
+        '    arg1 from testmodule',
+        'arg2',
+        '    arg2 from conftest',
+    ])
+
+
+def test_verbose_include_private_fixtures_and_loc(testdir):
+    testdir.makeconftest('''
+        import pytest
+        @pytest.fixture
+        def _arg1():
+            """_arg1 from conftest"""
+        @pytest.fixture
+        def arg2(_arg1):
+            """arg2 from conftest"""
+    ''')
+    p = testdir.makepyfile('''
+        import pytest
+        @pytest.fixture
+        def arg3():
+            """arg3 from testmodule"""
+        def test_args(arg2, arg3):
+            pass
+    ''')
+    result = testdir.runpytest("--fixtures-per-test", "-v", p)
+    assert result.ret == 0
+
+    result.stdout.fnmatch_lines([
+        '*fixtures used by test_args*',
+        '*(test_verbose_include_private_fixtures_and_loc.py:6)*',
+        '_arg1 -- conftest.py:3',
+        '    _arg1 from conftest',
+        'arg2 -- conftest.py:6',
+        '    arg2 from conftest',
+        'arg3 -- test_verbose_include_private_fixtures_and_loc.py:3',
+        '    arg3 from testmodule',
+    ])