VultureBear: Make use of the new vulture API

The new vulture API provides better integration with coala. It
natively supports `item.confidence`. Also, it gives precise
information about the location of dead code (`first_line, `last_line`)

.coafile

@@ -1,6 +1,7 @@
 [Default]
 files = *.py, bears/**/*.py, tests/**/*.py, bears/*.py.in
-ignore = tests/python/test_files/pylint_test.py, tests/python/bandit_test_files/*
+ignore = tests/python/test_files/pylint_test.py, tests/python/bandit_test_files/*,
+         tests/python/vulture_test_files/*
 
 max_line_length = 79
 use_spaces = True

bear-requirements.txt

@@ -34,6 +34,6 @@ rstcheck~=3.1
 safety~=0.5.1
 scspell3k~=2.0
 vim-vint~=0.3.12
-vulture~=0.14.0
+vulture~=0.25.0
 yamllint~=1.6.1
 yapf~=0.16.0

bears/python/VultureBear.py

@@ -3,42 +3,26 @@
 from dependency_management.requirements.PipRequirement import PipRequirement
 from vulture import Vulture
 
-CONFIDENCE_MAP = {
-    'attribute': 70,
-    'class': 70,
-    'function': 70,
-    'import': 95,
-    'property': 70,
-    'variable': 70,
-}
-
 
 def _find_unused_code(filenames):
     """
     :param filenames: List of filenames to check.
     :return: Generator of Result objects.
     """
-
-    def file_lineno(item):
-        return (item.filename.lower(), item.lineno)
-
     vulture = Vulture()
     vulture.scavenge(filenames)
-    for item in sorted(
-            vulture.unused_funcs + vulture.unused_imports +
-            vulture.unused_props + vulture.unused_vars +
-            vulture.unused_attrs, key=file_lineno):
-        message = 'Unused {0}: {1}'.format(item.typ, item)
+    for item in vulture.get_unused_code():
         yield Result.from_values(origin='VultureBear',
-                                 message=message,
+                                 message=item.message,
                                  file=item.filename,
-                                 line=item.lineno,
-                                 confidence=CONFIDENCE_MAP[item.typ])
+                                 line=item.first_lineno,
+                                 end_line=item.last_lineno,
+                                 confidence=item.confidence)
 
 
 class VultureBear(GlobalBear):
     LANGUAGES = {'Python', 'Python 3'}
-    REQUIREMENTS = {PipRequirement('vulture', '0.14.0')}
+    REQUIREMENTS = {PipRequirement('vulture', '0.25.0')}
     AUTHORS = {'The coala developers'}
     AUTHORS_EMAILS = {'[email protected]'}
     LICENSE = 'AGPL-3.0'

tests/python/VultureBearTest.py

@@ -1,3 +1,4 @@
+import os
 import unittest
 from queue import Queue
 from textwrap import dedent
@@ -9,6 +10,15 @@
 from bears.python.VultureBear import VultureBear
 
 
+def get_testfile_path(name):
+    return os.path.join(os.path.dirname(__file__), 'vulture_test_files', name)
+
+
+def load_testfile(name):
+    with open(get_testfile_path(name)) as f:
+        return f.read()
+
+
 class VultureBearTest(unittest.TestCase):
 
     def setUp(self):
@@ -42,85 +52,59 @@ def prep_file():
 
             return list(self.uut.run())
 
+    def verify_results(self, test_file, expected):
+        detected = dict((item.message, (item.affected_code[0].start.line,
+                                        item.affected_code[0].end.line,
+                                        item.confidence))
+                        for item in self.get_results(load_testfile(test_file)))
+        self.assertEqual(detected, expected)
+
     def test_used_variable(self):
-        good_file = """
-        x = 2
-        print(x)
-        """
-        self.assertEqual(len(self.get_results(good_file)), 0)
+        self.verify_results('used_variable.py', {})
 
     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
-
-        test(1)
-        """
-        self.assertEqual(len(self.get_results(bad_file)), 1)
-
-    def test_unused_function(self):
-        bad_file = """
-        def test(a):
-            return a
-        """
-        self.assertEqual(len(self.get_results(bad_file)), 1)
-
-    def test_import_confidence(self):
-        bad_file = """
-        from os import *
-        import subprocess
-        """
-        result = self.get_results(bad_file)
-        self.assertEqual(len(result), 1)
-        self.assertEqual(result[0].confidence, 95)
-
-    def test_class_confidence(self):
-        bad_file = """
-        class Name:
-
-            def __init__(self, name):
-                self.name = name
-                self.sur_name = 'Something'
-
-        """
-        result = self.get_results(bad_file)
-        self.assertEqual(len(result), 2)
-        self.assertEqual(result[0].confidence, 70)
-
-    def test_func_confidence(self):
-        bad_file = """
-        def hello(name):
-            print('Hello World')
-        """
-        result = self.get_results(bad_file)
-        self.assertEqual(len(result), 2)
-        self.assertEqual(result[0].confidence, 70)
-
-    def test_prop_confidence(self):
-        bad_file = """
-        class Bar(object):
-            @property
-            def prop(self):
-                pass
-
-        c = Bar()
-        """
-        result = self.get_results(bad_file)
-        self.assertEqual(len(result), 2)
-        self.assertEqual(result[0].confidence, 70)
-
-    def test_var_confidence(self):
-        bad_file = """
-        name = 'Foo Bar'
-        """
-        result = self.get_results(bad_file)
-        self.assertEqual(len(result), 1)
-        self.assertEqual(result[0].confidence, 70)
+        self.verify_results('unused_variable.py', {
+            "unused variable 'b'": (1, 1, 60)
+        })
+
+    def test_unused_arg(self):
+        self.verify_results('unused_arg.py', {
+            "unused variable 'a'": (1, 1, 100)
+        })
+
+    def test_import(self):
+        self.verify_results('unused_import.py', {
+            "unused import 'subprocess'": (2, 2, 90)
+        })
+
+    def test_class(self):
+        self.verify_results('unused_class.py', {
+            "unused class 'Name'": (1, 5, 60),
+            "unused attribute 'name'": (4, 4, 60),
+            "unused attribute 'surname'": (5, 5, 60)
+        })
+
+    def test_function(self):
+        self.verify_results('unused_function.py', {
+            "unused function 'hello'": (1, 2, 60)
+        })
+
+    def test_property(self):
+        self.verify_results('unused_property.py', {
+            "unused property 'prop'": (3, 5, 60)
+        })
+
+    def test_unsatisfiable_while(self):
+        self.verify_results('unsatisfiable_while.py', {
+            "unsatisfiable 'while' condition": (5, 7, 100)
+        })
+
+    def test_unsatisfiable_if(self):
+        self.verify_results('unsatisfiable_if.py', {
+            "unsatisfiable 'if' condition": (1, 2, 100)
+        })
+
+    def test_unreachable_else(self):
+        self.verify_results('unreachable_else.py', {
+            "unreachable 'else' block": (3, 6, 100)
+        })

tests/python/vulture_test_files/unreachable_else.py

@@ -0,0 +1,6 @@
+if True:
+    print('Reachable')
+elif something():
+    print('Never executed')
+else:
+    print('Unreachable')

tests/python/vulture_test_files/unsatisfiable_if.py

@@ -0,0 +1,2 @@
+if False:
+    print('Unreachable')

tests/python/vulture_test_files/unsatisfiable_while.py

@@ -0,0 +1,7 @@
+while True:
+    print('I am reachable.')
+    break
+
+while 0:
+    print('I am unreachable.')
+    print('I can be detected.')

tests/python/vulture_test_files/unused_arg.py

@@ -0,0 +1,5 @@
+def func(a):
+    pass
+
+
+func(1)

tests/python/vulture_test_files/unused_class.py

@@ -0,0 +1,5 @@
+class Name:
+
+    def __init__(self, name):
+        self.name = name
+        self.surname = 'Something'

tests/python/vulture_test_files/unused_function.py

@@ -0,0 +1,2 @@
+def hello(name):
+    print('Hello', name)

tests/python/vulture_test_files/unused_import.py

@@ -0,0 +1,2 @@
+from os import *
+import subprocess

tests/python/vulture_test_files/unused_property.py

@@ -0,0 +1,8 @@
+class Bar(object):
+
+    @property
+    def prop(self):
+        pass
+
+
+Bar()

tests/python/vulture_test_files/unused_variable.py

@@ -0,0 +1,3 @@
+b = 10
+a = 12
+print(a)

tests/python/vulture_test_files/used_variable.py

@@ -0,0 +1,2 @@
+x = 2
+print(x)