Hide cycle in testprojects

Cycle detection is tested in `test_sort_targets.py`, but having a cycle existing directly in the repo breaks implementations of graph parsing that validate cycles early. While `testprojects` is explicitly for "broken" code, keeping it `./pants list`able seems important for maintaining it.

- Move cycle detection integration test into `test_build_graph_integration` with mangled BUILD file names.

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/118118736

Bugs closed: 3058, 3081

Reviewed at https://rbcommons.com/s/twitter/r/3600/

tests/python/pants_test/backend/jvm/subsystems/test_jar_dependency_management_integration.py

@@ -27,13 +27,8 @@ class JarDependencyManagementIntegrationTest(PantsRunIntegrationTest):
 
   @contextmanager
   def _testing_build_file(self):
-    test_name = os.path.join(self.project, 'TEST_BUILD')
-    real_name = os.path.join(self.project, 'BUILD')
-    try:
-      os.rename(test_name, real_name)
+    with self.file_renamed(self.project, 'TEST_BUILD', 'BUILD'):
       yield
-    finally:
-      os.rename(real_name, test_name)
 
   def _run_project(self, spec_name, default_target=None, conflict_strategy=None):
     with self._testing_build_file():

tests/python/pants_test/backend/jvm/tasks/test_ivy_resolve_integration.py

@@ -14,13 +14,6 @@
 
 class IvyResolveIntegrationTest(PantsRunIntegrationTest):
 
-  def test_ivy_resolve_gives_correct_exception_on_cycles(self):
-    with self.temporary_workdir() as workdir:
-      pants_run = self.run_pants_with_workdir([
-          'compile', 'testprojects/src/java/org/pantsbuild/testproject/cycle1'], workdir)
-      self.assert_failure(pants_run)
-      self.assertIn('Cycle detected', pants_run.stderr_data)
-
   def test_java_compile_with_ivy_report(self):
     # Ensure the ivy report file gets generated
     with self.temporary_workdir() as workdir:

tests/python/pants_test/build_graph/BUILD

@@ -61,6 +61,15 @@ python_tests(
   ],
 )
 
+python_tests(
+  name = 'build_graph_integration',
+  sources = ['test_build_graph_integration.py'],
+  dependencies = [
+    'tests/python/pants_test:int-test',
+  ],
+  tags = {'integration'},
+)
+
 python_tests(
   name = 'source_mapper',
   sources = ['test_source_mapper.py'],

tests/python/pants_test/build_graph/test_build_graph_integration.py

@@ -0,0 +1,21 @@
+# coding=utf-8
+# Copyright 2016 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+from __future__ import (absolute_import, division, generators, nested_scopes, print_function,
+                        unicode_literals, with_statement)
+
+import os
+
+from pants_test.pants_run_integration_test import PantsRunIntegrationTest
+
+
+class BuildGraphIntegrationTest(PantsRunIntegrationTest):
+
+  def test_cycle(self):
+    prefix = 'testprojects/src/java/org/pantsbuild/testproject'
+    with self.file_renamed(os.path.join(prefix, 'cycle1'), 'TEST_BUILD', 'BUILD'):
+      with self.file_renamed(os.path.join(prefix, 'cycle2'), 'TEST_BUILD', 'BUILD'):
+        pants_run = self.run_pants(['compile', os.path.join(prefix, 'cycle1')])
+        self.assert_failure(pants_run)
+        self.assertIn('Cycle detected', pants_run.stderr_data)

tests/python/pants_test/pants_run_integration_test.py

@@ -255,3 +255,13 @@ def indent(content):
   def normalize(self, s):
     """Removes escape sequences (e.g. colored output) and all whitespace from string s."""
     return ''.join(strip_color(s).split())
+
+  @contextmanager
+  def file_renamed(self, prefix, test_name, real_name):
+    real_path = os.path.join(prefix, real_name)
+    test_path = os.path.join(prefix, test_name)
+    try:
+      os.rename(test_path, real_path)
+      yield
+    finally:
+      os.rename(real_path, test_path)

tests/python/pants_test/projects/test_testprojects_integration.py

@@ -33,8 +33,6 @@ def tests_testprojects(self):
       'testprojects/src/antlr/pants/backend/python/test:antlr_failure',
       'testprojects/src/java/org/pantsbuild/testproject/bundle:missing-files',
       'testprojects/src/java/org/pantsbuild/testproject/compilation_warnings:fatal',
-      'testprojects/src/java/org/pantsbuild/testproject/cycle1',
-      'testprojects/src/java/org/pantsbuild/testproject/cycle2',
       'testprojects/src/java/org/pantsbuild/testproject/dummies:compilation_failure_target',
       'testprojects/src/java/org/pantsbuild/testproject/junit/beforeclassexception:tests',
       'testprojects/src/java/org/pantsbuild/testproject/junit/failing/tests/org/pantsbuild/tmp/tests',