Merge pull request #3 from fruch/master

 Adding pydot --fixture-graph

Author: amakhnach

.travis.yml

@@ -1,10 +1,15 @@
 language: python
+python:
+  - "2.7"
+  - "3.4"
+  - "3.5"
+  - "3.6"
+  - "nightly"
 # command to install dependencies
 install:
   - pip install python-coveralls virtualenv
 # # command to run tests
-script: python setup.py test
-after_success:
+script:
   - pip install -r requirements-testing.txt -e .
   - py.test --cov=pytest_fixture_tools --cov-report=term-missing tests
   - coveralls

README.rst

@@ -22,6 +22,9 @@ Installation
 Usage
 -----
 
+show-fixture-duplicates
+***********************
+
 If you have already installed ``pytest-fixture-tools`` plugin then you can use one of its commands.
 
 ``--show-fixture-duplicates`` - will collect all fixtures and print you a list of duplicates for each fixture.
@@ -47,6 +50,55 @@ Output can look like this:
     tests/fixtures/order.py:30
     tests/unit/api/conftest.py:261
 
+fixture-graph
+*************
+
+You can generate the usage fixture graph like that:
+
+.. sourcecode:: bash
+
+    # on windows gitbash as example
+    export PATH=$PATH:/c/Program\ Files\ \(x86\)/Graphviz2.38/bin/
+    pytest --fixture-graph -s
+
+    # or you can select the output direcotry like that:
+    pytest --fixture-graph --fixture-graph-output-dir=./test_output
+
+    # you can also change the output type of the graphs (any of graphvis supported outputs types):
+    pytest --fixture-graph --fixture-graph-type=jpg
+
+The output would be like that:
+
+.. sourcecode::
+
+   ============================= test session starts =============================
+   platform win32 -- Python 2.7.10, pytest-3.3.1, py-1.5.2, pluggy-0.6.0
+   rootdir: C:\Users\ifruchte\Projects\pytest-fixture-tools, inifile: tox.ini
+   plugins: pep8-1.0.6, cov-2.5.1, fixture-tools-1.0.0
+   collected 7 items
+
+   pytest_fixture_tools\__init__.py .                                       [ 14%]
+   pytest_fixture_tools\plugin.py .                                         [ 28%]
+   tests\__init__.py .                                                      [ 42%]
+   tests\conftest.py .                                                      [ 57%]
+   tests\test_fixture_duplicates.py .
+   -------------------------------- fixture-graph --------------------------------
+   created artifacts/fixture-graph-tests-test_fixture_duplicates.py__test_there_are_fixture_duplicates.png.
+   ============================= test session starts =============================
+   platform win32 -- Python 2.7.10, pytest-3.3.1, py-1.5.2, pluggy-0.6.0
+   rootdir: c:\users\ifruchte\appdata\local\temp\pytest-of-ifruchte\pytest-445\test_there_are_not_fixture_duplicates0, inifile:
+   plugins: pep8-1.0.6, cov-2.5.1, fixture-tools-1.0.0
+   collected 2 items
+
+   ======================== no tests ran in 0.06 seconds =========================
+   .s                                     [100%]
+
+   ===================== 6 passed, 1 skipped in 0.29 seconds =====================
+
+Final output, that can help with tests that depend on large amount of fixtures:
+
+.. image:: imgs/graph_example.png
+    :alt: alternate text
 
 Contact
 -------

imgs/graph_example.png

@@ -1,14 +1,28 @@
 """Pytest fixture tools plugin."""
 
 import py
+import os
+import errno
 
 from _pytest.python import getlocation
 from collections import defaultdict
 
+import pydot
+
 tw = py.io.TerminalWriter()
 verbose = 1
 
 
+def mkdir_recursive(path):
+    try:
+        os.makedirs(path)
+    except OSError as exc:
+        if exc.errno == errno.EEXIST and os.path.isdir(path):
+            pass
+        else:
+            raise
+
+
 def pytest_addoption(parser):
     """Add commandline options show-fixture-duplicates and fixture."""
     group = parser.getgroup("general")
@@ -19,6 +33,16 @@ def pytest_addoption(parser):
                     action="store", type=str, dest="fixture_name", default='',
                     help="Name of specific fixture for which you want to get duplicates")
 
+    group.addoption('--fixture-graph',
+                    action="store_true", dest="fixture_graph", default=False,
+                    help="create .dot fixture graph for each test")
+    group.addoption('--fixture-graph-output-dir',
+                    action="store_true", dest="fixture_graph_output_dir", default="artifacts",
+                    help="select the location for the output of fixture graph. defaults to 'artifacts'")
+    group.addoption('--fixture-graph-output-type',
+                    action="store_true", dest="fixture_graph_output_type", default="png",
+                    help="select the type of the output for the fixture graph. defaults to 'png'")
+
 
 def pytest_cmdline_main(config):
     """Check show_fixture_duplicates option to show fixture duplicates."""
@@ -93,3 +117,40 @@ def _show_fixture_duplicates_main(config, session):
         for argname, fixtures in available:
             print_duplicates(argname, fixtures, previous_argname)
             previous_argname = argname
+
+
+def pytest_runtest_setup(item):
+    if item.config.option.fixture_graph and hasattr(item, "_fixtureinfo"):
+        # fixtures came from function parameters names
+        data = dict()
+        data['func_args'] = item._fixtureinfo.argnames, 'red'
+        for fixture_name, fixture_data in list(item._fixtureinfo.name2fixturedefs.items()):
+
+            color = 'green'
+            data[fixture_name] = fixture_data[0].argnames, color
+
+        graph = pydot.Dot(graph_type='digraph')
+
+        for name, depended_list in list(data.items()):
+            depended_list, color = depended_list
+
+            node = pydot.Node(name, style="filled", fillcolor=color)
+            graph.add_node(node)
+            for i in depended_list:
+                edge = pydot.Edge(node, i)
+                graph.add_edge(edge)
+
+        log_dir = item.config.option.fixture_graph_output_dir
+        output_type = item.config.option.fixture_graph_output_type
+        mkdir_recursive(log_dir)
+        filename = "{0}/fixture-graph-{1}".format(log_dir, item._nodeid.replace(":", "_").replace("/", "-"))
+        tw.line()
+        tw.sep("-", "fixture-graph")
+        try:
+            graph.write("{}.{}".format(filename, output_type), format=output_type)
+            tw.line("created {}.{}.".format(filename, output_type))
+        except Exception:
+            tw.line("graphvis wasn't found in PATH")
+            graph.write(filename + ".dot")
+            tw.line("created {}.dot.".format(filename))
+            tw.line("You can convert it to a PNG using:\n\t'dot -Tpng {0}.dot -o {0}.png'".format(filename))

pytest_fixture_tools/plugin.py

@@ -52,7 +52,7 @@ def run_tests(self):
     ] + [('Programming Language :: Python :: %s' % x) for x in '2.6 2.7 3.0 3.1 3.2 3.3'.split()],
     cmdclass={'test': ToxTestCommand},
     install_requires=[
-        'pytest',
+        'pytest', 'pydot'
     ],
     # the following makes a plugin available to py.test
     entry_points={

setup.py

@@ -0,0 +1,28 @@
+import py
+
+
+def test_fixture_graph_created(testdir):
+    """Check that --fixture-graph will create the graph .dot file"""
+    sub1 = testdir.mkpydir("sub1")
+    sub2 = testdir.mkpydir("sub1/sub2")
+    sub1.join("conftest.py").write(py.code.Source("""
+        import pytest
+
+        @pytest.fixture
+        def arg1(request):
+            pass
+    """))
+    sub2.join("conftest.py").write(py.code.Source("""
+        import pytest
+
+        @pytest.fixture
+        def arg1(request):
+            pass
+    """))
+    sub1.join("test_in_sub1.py").write("def test_1(arg1): pass")
+    sub2.join("test_in_sub2.py").write("def test_2(arg1): pass")
+
+    result = testdir.runpytest_subprocess('--fixture-graph', '-s')
+
+    result.stdout.fnmatch_lines("created artifacts/fixture-graph-sub1-test_in_sub1.py__test_1.dot.")
+    result.stdout.fnmatch_lines('created artifacts/fixture-graph-sub1-sub2-test_in_sub2.py__test_2.dot.')

tests/test_fixtrue_graph.py

@@ -1,5 +1,6 @@
 """Test for checking getting of duplicates."""
 import py
+import pytest
 
 
 def test_there_are_not_fixture_duplicates(testdir):
@@ -49,7 +50,7 @@ def arg1(request):
     sub1.join("test_in_sub1.py").write("def test_1(arg1): pass")
     sub2.join("test_in_sub2.py").write("def test_2(arg1): pass")
 
-    result = testdir.runpytest('--show-fixture-duplicates')
+    result = testdir.runpytest_subprocess('--show-fixture-duplicates', '-s')
 
-    assert result.stdout.lines.count('sub1/conftest.py:5') == 1
-    assert result.stdout.lines.count('sub1/sub2/conftest.py:5') == 1
+    result.stdout.fnmatch_lines('sub1/conftest.py:5')
+    result.stdout.fnmatch_lines('sub1/sub2/conftest.py:5')