Add test_render_tree_cyclic_dependency

Test for issue in #13 (https://github.com/naiquevin/pipdeptree/issues/13)

tests/cyclic_deps.pickle

@@ -0,0 +1,85 @@
+(lp0
+ccopy_reg
+_reconstructor
+p1
+(cpip._vendor.pkg_resources
+Distribution
+p2
+c__builtin__
+object
+p3
+Ntp4
+Rp5
+(dp6
+S'project_name'
+p7
+S'CircularDependencyA'
+p8
+sS'precedence'
+p9
+I-1
+sS'_key'
+p10
+S'circulardependencya'
+p11
+sS'_version'
+p12
+S'0.0.0'
+p13
+sS'platform'
+p14
+NsS'location'
+p15
+S'.tox/cyclic_deps/lib/python2.7/site-packages'
+p16
+sS'py_version'
+p17
+S'2.7'
+p18
+sS'_provider'
+p19
+(ipip._vendor.pkg_resources
+PathMetadata
+p20
+(dp21
+S'module_path'
+p22
+g16
+sS'egg_info'
+p23
+S'.tox/cyclic_deps/lib/python2.7/site-packages/CircularDependencyA-0.0.0-py2.7.egg-info'
+p24
+sbsbag1
+(g2
+g3
+Ntp25
+Rp26
+(dp27
+g7
+S'CircularDependencyB'
+p28
+sg9
+I-1
+sg10
+S'circulardependencyb'
+p29
+sg12
+S'0.0.0'
+p30
+sg14
+Nsg15
+g16
+sg17
+S'2.7'
+p31
+sg19
+(ipip._vendor.pkg_resources
+PathMetadata
+p32
+(dp33
+g22
+g16
+sg23
+S'.tox/cyclic_deps/lib/python2.7/site-packages/CircularDependencyB-0.0.0-py2.7.egg-info'
+p34
+sbsba.

tests/test_pipdeptree.py

@@ -79,3 +79,33 @@ def test_render_tree_freeze():
     assert '  - SQLAlchemy==0.9.1' in lines
     assert '-e git+https://github.com/naiquevin/lookupy.git@cdbe30c160e1c29802df75e145ea4ad903c05386#egg=Lookupy-master' in lines
     assert 'itsdangerous==0.23' not in lines
+
+
+def test_render_tree_cyclic_dependency():
+    with open('tests/cyclic_deps.pickle', 'rb') as f:
+        cyclic_pkgs = pickle.load(f)
+
+    list_all = True
+
+    tree_str = render_tree(cyclic_pkgs, pkg_index, req_map, list_all,
+                           top_pkg_name, non_top_pkg_name)
+    lines = set(tree_str.split('\n'))
+    assert 'CircularDependencyA==0.0.0' in lines
+    assert '  - CircularDependencyB [installed: 0.0.0]' in lines
+    assert 'CircularDependencyB==0.0.0' in lines
+    assert '  - CircularDependencyA [installed: 0.0.0]' in lines
+
+
+def test_render_tree_freeze_cyclic_dependency():
+    with open('tests/cyclic_deps.pickle', 'rb') as f:
+        cyclic_pkgs = pickle.load(f)
+
+    list_all = True
+
+    tree_str = render_tree(cyclic_pkgs, pkg_index, req_map, list_all,
+                           top_pkg_src, non_top_pkg_src)
+    lines = set(tree_str.split('\n'))
+    assert 'CircularDependencyA==0.0.0' in lines
+    assert '  - CircularDependencyB==0.0.0' in lines
+    assert 'CircularDependencyB==0.0.0' in lines
+    assert '  - CircularDependencyA==0.0.0' in lines

tests/virtualenvs/cyclic_deps_requirements.txt

@@ -0,0 +1,2 @@
+CircularDependencyA
+CircularDependencyB

tests/virtualenvs/cyclic_requirements.txt

@@ -0,0 +1,65 @@
+# Jinja2==2.7.3
+# Mako==0.9.1
+# MarkupSafe==0.23
+# Paste==1.7.5.1
+# PasteDeploy==1.5.2
+# PasteScript==1.7.5
+# PyYAML==3.10
+# Pygments==1.6
+RAttr==0.6.2
+# SQLAlchemy==0.9.4
+WebOb==1.4
+# WebTest==2.0.15
+# alembic==0.6.5dev
+# argparse==1.2.1
+# beautifulsoup4==4.3.2
+# colorama==0.3.1
+# contextdecorator==0.10.0
+cornice==0.16.2
+# cov-core==1.12
+# coverage==3.7.1
+# decorator==3.4.0
+# dogpile.cache==0.5.3
+# dogpile.core==0.4.1
+# fancycompleter==0.4
+# gevent==1.0.1
+# greenlet==0.4.2
+# gunicorn==19.0.0
+# jsonschema==2.3.0
+# mock==1.0.1
+# msgpack-python==0.4.0
+# nose==1.3.3
+# parameterizedtestcase==0.1.0
+# pdbpp==0.7.2
+pipdeptree==0.3
+# py==1.4.18
+# pylibmc==1.2.3
+# pymssql==2.1.0
+pyramid==1.5.1
+pyramid-jinja2==2.3
+# pyrepl==0.8.4
+# pytest==2.4.2
+# pytest-cov==1.6
+# redis==2.9.1
+# repoze.lru==0.6
+# requests==2.2.1
+# simplejson==3.3.0
+# six==1.6.1
+smlib.appstatus==0.0.13
+smlib.cache==1.0.7
+smlib.enums==0.0.4
+smlib.log==0.0.7
+smlib.service==0.1.33
+# smlib.smsqlalchemy==0.13
+smlib.traceback==0.3
+smlib.validate==0.0.10
+smsdk.authsvc==0.0.8
+smsdk.usersvc==0.0.8
+translationstring==1.1
+# vcrpy==0.7.0
+# venusian==1.0a8
+# waitress==0.8.8
+# wmctrl==0.1
+# wsgiref==0.1.2
+# zope.deprecation==4.1.1
+# zope.interface==4.1.1