Add docs and extra test case

README.md

@@ -19,6 +19,7 @@ tool for higher code quality.
 * tested: tests itself and has complete test coverage
 * complements pyflakes and has the same output syntax
 * sorts unused classes and functions by size with `--sort-by-size`
+* respects `# noqa` comments
 * supports Python 2.7 and Python \>= 3.5
 
 ## Installation
@@ -58,6 +59,16 @@ We collect whitelists for common Python modules and packages in
 a whole file or directory, use the `--exclude` parameter (e.g.,
 `--exclude *settings.py,docs/`).
 
+The other, more common way of ignoring results is to annotate the line causing
+the false positive with `# noqa <ERROR_CODE>` in a trailing comment.
+
+The `ERROR_CODE` specifies what kind of dead code to ignore (see the table
+below for details). In case no error code is specified, Vulture ignores all
+results for the line.
+
+Note that the line number for any decorated object is the same as the line
+number of the first decorator.
+
 **Ignoring names**
 
 You can use `--ignore-names foo*,ba[rz]` to let Vulture ignore all names
@@ -130,9 +141,9 @@ Calling :
 
 results in the following output:
 
-    dead_code.py:1: unused import 'os' (90% confidence)
-    dead_code.py:4: unused function 'greet' (60% confidence)
-    dead_code.py:8: unused variable 'message' (60% confidence)
+    dead_code.py:1: V104 unused import 'os' (90% confidence)
+    dead_code.py:4: V103 unused function 'greet' (60% confidence)
+    dead_code.py:8: V106 unused variable 'message' (60% confidence)
 
 Vulture correctly reports "os" and "message" as unused, but it fails to
 detect that "greet" is actually used. The recommended method to deal
@@ -158,8 +169,39 @@ Passing both the original program and the whitelist to Vulture
 
 makes Vulture ignore the `greet` method:
 
-    dead_code.py:1: unused import 'os' (90% confidence)
-    dead_code.py:8: unused variable 'message' (60% confidence)
+    dead_code.py:1: V104 unused import 'os' (90% confidence)
+    dead_code.py:8: V106 unused variable 'message' (60% confidence)
+
+**Using "# noqa"**
+
+```python
+import os
+
+class Greeter:
+    def greet(self):  # noqa: V103
+        print("Hi")
+
+def hello_world():
+    message = "Hello, world!"
+    greeter = Greeter()
+    greet_func = getattr(greeter, "greet")
+    greet_func()
+
+if __name__ == "__main__":
+    hello_world()
+```
+
+## Error codes
+
+| Error Code |    Description    |
+| ---------- | ----------------- |
+|    V101    | Unused Attribute  |
+|    V102    | Unused Class      |
+|    V103    | Unused Function   |
+|    V104    | Unused Import     |
+|    V105    | Unused Property   |
+|    V106    | Unused Variable   |
+|    V201    | Unreachable Code  |
 
 ## Exit codes
 

tests/test_noqa.py

@@ -1,6 +1,6 @@
 import pytest
 
-from vulture.noqa import NOQA_REGEXP, parse_error_codes
+from vulture.noqa import NOQA_REGEXP, _parse_error_codes
 from . import check, v
 
 assert v  # Silence pyflakes.
@@ -19,7 +19,7 @@
 )
 def test_noqa_regex_present(line, codes):
     match = NOQA_REGEXP.search(line)
-    parsed = parse_error_codes(match)
+    parsed = _parse_error_codes(match)
     assert parsed == codes
 
 
@@ -277,3 +277,16 @@ def test_noqa_with_invalid_codes(v):
 """
     )
     check(v.unused_imports, ["this"])
+
+
+@pytest.mark.parametrize(
+    "first_file, second_file",
+    [
+        ("foo = None", "bar = None  # noqa"),
+        ("bar = None  # noqa", "foo = None"),
+    ],
+)
+def test_noqa_multiple_files(first_file, second_file, v):
+    v.scan(first_file, filename="first_file.py")
+    v.scan(second_file, filename="second_file.py")
+    check(v.unused_vars, ["foo"])

tests/test_script.py

@@ -1,3 +1,4 @@
+import glob
 import os.path
 import subprocess
 import sys
@@ -61,12 +62,7 @@ def call_vulture_with_excludes(excludes):
         return call_vulture(["vulture/", "--exclude", get_csv(excludes)])
 
     assert call_vulture_with_excludes(["core.py", "utils.py"]) == 1
-    assert (
-        call_vulture_with_excludes(
-            ["core.py", "utils.py", "lines.py", "noqa.py"]
-        )
-        == 0
-    )
+    assert call_vulture_with_excludes(glob.glob("vulture/*.py")) == 0
 
 
 def test_make_whitelist():

vulture/core.py

@@ -27,7 +27,6 @@
 
 import argparse
 import ast
-from collections import defaultdict
 from fnmatch import fnmatch, fnmatchcase
 import os.path
 import pkgutil
@@ -476,13 +475,11 @@ def _define(
         ignore=None,
     ):
         def ignored(lineno):
-            if (ignore and ignore(self.filename, name)) or _match(
-                name, self.ignore_names
-            ):
-                return True
-
-            # Check if the reported line is annotated with "# noqa".
-            return noqa.ignore_line(self.noqa_lines, lineno, typ)
+            return (
+                (ignore and ignore(self.filename, name))
+                or _match(name, self.ignore_names)
+                or noqa.ignore_line(self.noqa_lines, lineno, ERROR_CODES[typ])
+            )
 
         last_node = last_node or first_node
         typ = collection.typ

vulture/noqa.py

@@ -14,7 +14,7 @@
 )
 
 
-def parse_error_codes(match):
+def _parse_error_codes(match):
     # If no error code is specified, add the line to the "all" category.
     return [
         c.strip() for c in (match.groupdict()["codes"] or "all").split(",")
@@ -26,15 +26,11 @@ def parse_noqa(code):
     for lineno, line in enumerate(code, start=1):
         match = NOQA_REGEXP.search(line)
         if match:
-            for error_code in parse_error_codes(match):
+            for error_code in _parse_error_codes(match):
                 noqa_lines[error_code].add(lineno)
     return noqa_lines
 
 
-def ignore_line(noqa_lines, lineno, typ):
+def ignore_line(noqa_lines, lineno, error_code):
     """Check if the reported line is annotated with "# noqa"."""
-    from vulture.core import ERROR_CODES
-
-    return (
-        lineno in noqa_lines[ERROR_CODES[typ]] or lineno in noqa_lines["all"]
-    )
+    return lineno in noqa_lines[error_code] or lineno in noqa_lines["all"]