VultureBear: Convert to global bear

Fixes coala#817

bears/python/VultureBear.py

@@ -1,16 +1,13 @@
-from coalib.bearlib.abstractions.Linter import linter
-from coalib.bears.requirements.PipRequirement import PipRequirement
+import re
+from shutil import which
 
+from coalib.bears.GlobalBear import GlobalBear
+from coalib.bears.requirements.PipRequirement import PipRequirement
+from coalib.misc.Shell import run_shell_command
+from coalib.results.Result import Result
 
-@linter(executable='vulture',
-        output_format='regex',
-        output_regex=r'(?P<filename>.*):(?P<line>.*):\s*(?P<message>.*)')
-class VultureBear:
-    """
-    Checks Python code for unused variables and functions using ``vulture``.
 
-    See <https://bitbucket.org/jendrikseipp/vulture> for more information.
-    """
+class VultureBear(GlobalBear):
     LANGUAGES = {'Python', 'Python 3'}
     REQUIREMENTS = {PipRequirement('vulture', '0.10.0')}
     AUTHORS = {'The coala developers'}
@@ -19,6 +16,30 @@ class VultureBear:
     ASCIINEMA_URL = 'https://asciinema.org/a/82256'
     CAN_DETECT = {'Unused Code'}
 
-    @staticmethod
-    def create_arguments(filename, file, config_file):
-        return filename,
+    EXECUTABLE = 'vulture'
+    OUTPUT_REGEX = re.compile(
+        r'(?P<filename>.*):(?P<line>.*):\s*(?P<message>.*)')
+
+    @classmethod
+    def check_prerequisites(cls):
+        return ('Vulture is missing. Make sure to install it using '
+                '`pip3 install vulture`.'
+                if which('vulture') is None else True)
+
+    def run(self):
+        """
+        Check Python code for unused variables and functions using `vulture`.
+
+        See <https://bitbucket.org/jendrikseipp/vulture> for more information.
+        """
+        stdout_output, _ = run_shell_command(
+            (self.EXECUTABLE,) +
+            tuple(filename for filename in self.file_dict.keys()),
+            cwd=self.get_config_dir())
+
+        for match in re.finditer(self.OUTPUT_REGEX, stdout_output):
+            groups = match.groupdict()
+            yield Result.from_values(origin=self,
+                                     message=groups['message'],
+                                     file=groups['filename'],
+                                     line=int(groups['line']))

tests/python/VultureBearTest.py

@@ -1,18 +1,74 @@
+import unittest
+from queue import Queue
+from textwrap import dedent
+from contextlib import ExitStack, contextmanager
+
+from coala_utils.ContextManagers import prepare_file
+from coalib.settings.Section import Section
+
 from bears.python.VultureBear import VultureBear
-from tests.LocalBearTestHelper import verify_local_bear
 
 
-good_file = """
-x = 2
-print(x)
-"""
+class VultureBearTest(unittest.TestCase):
+
+    def setUp(self):
+        self.section = Section('name')
+        self.queue = Queue()
+        self.file_dict = {}
+        self.uut = VultureBear(self.file_dict, self.section, self.queue)
+
+    def get_results(self, *files):
+        """
+        Runs the bears with the files given.
+
+        :param files: A list of lists containing the file lines. File contents
+                      will automatically be dedented and splitted.
+        :return:      A list of the results of the uut!
+        """
+        with ExitStack() as stack:
+            for file in files:
+                @contextmanager
+                def prep_file():
+                    with prepare_file(
+                        dedent(file).splitlines(True),
+                        None,
+                        tempfile_kwargs={'suffix': '.py'}
+                    ) as lines_filename:
+                        lines, filename = lines_filename
+                        self.file_dict[filename] = file
+                        yield
+
+                stack.enter_context(prep_file())
+
+            return list(self.uut.run())
+
+    def test_used_variable(self):
+        good_file = """
+        x = 2
+        print(x)
+        """
+        self.assertEqual(len(self.get_results(good_file)), 0)
+
+    def test_unused_variable(self):
+        bad_file = """
+        b = 10
+        a = 12
+        print(a)
+        """
+        self.assertEqual(len(self.get_results(bad_file)), 1)
+
+    def test_unused_parameter(self):
+        bad_file = """
+        def test(a):
+            return 1
 
-bad_file = """
-b = 10
-a = 12
-print(a)
-"""
+        test(1)
+        """
+        self.assertEqual(len(self.get_results(bad_file)), 1)
 
-VultureBear = verify_local_bear(VultureBear,
-                                valid_files=(good_file,),
-                                invalid_files=(bad_file,))
+    def test_unused_function(self):
+        bad_file = """
+        def test(a):
+            return a
+        """
+        self.assertEqual(len(self.get_results(bad_file)), 1)