Fix for idea-plugin goal that generates too long project filename

Earlier in order to generate meaningful names for intellij, idea-plugin concatenates all target specs. However it will easily exceed the limit of UNIX filename length given a few target specs. This fix limits the name to up to 200 characters.

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/159747876

Bugs closed: 3863

Reviewed at https://rbcommons.com/s/twitter/r/4231/

src/python/pants/backend/project_info/tasks/idea_plugin_gen.py

@@ -54,6 +54,8 @@ class IdeaPluginGen(ConsoleTask):
   existing skeleton project into a Pants project as if user is importing these targets.
   """
 
+  PROJECT_NAME_LIMIT = 200
+
   @classmethod
   def register_options(cls, register):
     super(IdeaPluginGen, cls).register_options(register)
@@ -105,7 +107,8 @@ def __init__(self, *args, **kwargs):
 
   @classmethod
   def get_project_name(cls, target_specs):
-    return re.sub('[^0-9a-zA-Z:_]+', '.', '__'.join(target_specs))
+    # take up to PROJECT_NAME_LIMIT chars as project file name due to filesystem constraint.
+    return re.sub('[^0-9a-zA-Z:_]+', '.', '__'.join(target_specs))[:cls.PROJECT_NAME_LIMIT]
 
   # TODO: https://github.com/pantsbuild/pants/issues/3198
   def generate_project(self):

tests/python/pants_test/backend/project_info/tasks/test_idea_plugin_integration.py

@@ -11,12 +11,12 @@
 
 from pants.backend.project_info.tasks.idea_plugin_gen import IDEA_PLUGIN_VERSION, IdeaPluginGen
 from pants.base.build_environment import get_buildroot
+from pants.base.cmd_line_spec_parser import CmdLineSpecParser
 from pants.util.contextutil import temporary_file
 from pants_test.pants_run_integration_test import PantsRunIntegrationTest
 
 
 class IdeaPluginIntegrationTest(PantsRunIntegrationTest):
-
   def _do_check(self, project_dir_path, expected_project_path, expected_targets):
     """Check to see that the project contains the expected source folders."""
 
@@ -49,46 +49,62 @@ def _get_project_dir(self, output_file):
     with open(output_file, 'r') as result:
       return result.readlines()[0]
 
-  def _run_and_check(self, project_path, targets):
+  def _run_and_check(self, target_specs):
+    """
+    Invoke idea-plugin goal and check for target specs and project in the
+    generated project and workspace file.
+
+    :param target_specs: list of target specs
+    :return: n/a
+    """
+    self.assertTrue("targets are empty", target_specs)
+    spec_parser = CmdLineSpecParser(get_buildroot())
+    # project_path is always the directory of the first target,
+    # which is where intellij is going to zoom in under project view.
+    project_path = spec_parser.parse_spec(target_specs[0]).directory
+
     with self.temporary_workdir() as workdir:
       with temporary_file(root_dir=workdir, cleanup=True) as output_file:
         pants_run = self.run_pants_with_workdir(
-          ['idea-plugin', '--output-file={}'.format(output_file.name), '--no-open'] + targets, workdir)
+          ['idea-plugin', '--output-file={}'.format(output_file.name), '--no-open'] + target_specs, workdir)
         self.assert_success(pants_run)
 
         project_dir = self._get_project_dir(output_file.name)
         self.assertTrue(os.path.exists(project_dir), "{} does not exist".format(project_dir))
-        self._do_check(project_dir, project_path, targets)
+        self._do_check(project_dir, project_path, target_specs)
 
   def test_idea_plugin_single_target(self):
-
     target = 'examples/src/scala/org/pantsbuild/example/hello:hello'
-    project_path = "examples/src/scala/org/pantsbuild/example/hello"
 
-    self._run_and_check(project_path, [target])
+    self._run_and_check([target])
 
   def test_idea_plugin_single_directory(self):
     target = 'testprojects/src/python/antlr::'
-    project_path = "testprojects/src/python/antlr"
 
-    self._run_and_check(project_path, [target])
+    self._run_and_check([target])
 
   def test_idea_plugin_multiple_targets(self):
     target_a = 'examples/src/scala/org/pantsbuild/example/hello:'
     target_b = 'testprojects/src/python/antlr::'
 
-    # project_path is always the directory of the first target,
-    # which is where intellij is going to zoom in at project view.
-    project_path = 'examples/src/scala/org/pantsbuild/example/hello'
-
-    self._run_and_check(project_path, [target_a, target_b])
+    self._run_and_check([target_a, target_b])
 
   def test_idea_plugin_project_name(self):
     self.assertEqual(
       'examples.src.scala.org.pantsbuild.example.hello:__testprojects.src.python.antlr::',
       IdeaPluginGen.get_project_name([
-          'examples/src/scala/org/pantsbuild/example/hello:',
-          'testprojects/src/python/antlr::'
-        ]
+        'examples/src/scala/org/pantsbuild/example/hello:',
+        'testprojects/src/python/antlr::'
+      ]
       )
     )
+
+  def test_idea_plugin_long_project_name(self):
+    list_run = self.run_pants(['-q', 'list', 'testprojects/tests/java/org/pantsbuild/testproject/::'])
+    self.assert_success(list_run)
+    self.assertGreater(len(list_run.stdout_data), IdeaPluginGen.PROJECT_NAME_LIMIT)
+
+    a_lot_of_targets = [l for l in list_run.stdout_data.splitlines() if l]
+
+    self.assertEqual(IdeaPluginGen.PROJECT_NAME_LIMIT, len(IdeaPluginGen.get_project_name(a_lot_of_targets)))
+    self._run_and_check(a_lot_of_targets)