Fix #19, only run linters that are selected

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 ### Changed
 - Cache namespace results and minimize kwarg checks by grouping similar rules - ~500% speed up ([#18](https://github.com/dlint-py/dlint/issues/18))
+- Only run linters that are selected - speed up depends on number of linters seleted ([#19](https://github.com/dlint-py/dlint/issues/19))
 
 ### Fixed
 - The `--print-dlint-linters` flag on Windows ([#17](https://github.com/dlint-py/dlint/issues/17))

dlint/extension.py

@@ -13,12 +13,15 @@
 import optparse
 import sys
 
+from flake8 import style_guide
+
 import dlint
 
 
 class Flake8Extension(object):
     name = dlint.__name__
     version = dlint.__version__
+    options = None
 
     def __init__(self, tree, filename):
         self.tree = tree
@@ -44,7 +47,7 @@ def add_options(cls, parser):
     def parse_options(cls, options):
         if options.print_dlint_linters:
             code_prefix_len = 7
-            linters = Flake8Extension.get_linter_classes()
+            linters = cls.get_linter_classes()
             output_lines = [
                 "{} {} {}".format(l._code, l.__name__, l._error_tmpl[code_prefix_len:])
                 for l in sorted(linters, key=lambda li: li._code)
@@ -53,6 +56,8 @@ def parse_options(cls, options):
             EX_OK = 0
             sys.exit(EX_OK)
 
+        cls.options = options
+
     @classmethod
     def get_plugin_linter_classes(cls):
         module_prefix = 'dlint_plugin_'
@@ -74,7 +79,17 @@ def get_plugin_linter_classes(cls):
 
     @classmethod
     def get_linter_classes(cls):
-        return dlint.linters.ALL + tuple(cls.get_plugin_linter_classes())
+        linter_classes = dlint.linters.ALL + tuple(cls.get_plugin_linter_classes())
+
+        if cls.options:
+            engine = style_guide.DecisionEngine(cls.options)
+            selected = style_guide.Decision.Selected
+            linter_classes = tuple(
+                linter_class for linter_class in linter_classes
+                if engine.decision_for(linter_class._code) is selected
+            )
+
+        return linter_classes
 
     def run(self):
         linter_instances = [l() for l in self.get_linter_classes()]

tests/test_extension.py

@@ -7,6 +7,8 @@
     unicode_literals,
 )
 
+import argparse
+import contextlib
 import os
 import sys
 import unittest
@@ -31,6 +33,30 @@
 import extension  # noqa: E402
 
 
+def create_options(**kwargs):
+    kwargs.setdefault("select", [])
+    kwargs.setdefault("extended_default_select", ["DUO"])
+    kwargs.setdefault("ignore", [])
+    kwargs.setdefault("extend_ignore", [])
+    kwargs.setdefault("disable_noqa", False)
+    kwargs.setdefault("enable_extensions", [])
+
+    return argparse.Namespace(**kwargs)
+
+
+@contextlib.contextmanager
+def extension_with_options(options):
+    # Flake8 requires an extension's options to be set as a class
+    # variable. We have to ensure options are reset back to None after the
+    # extension is used or all class instances will retain the set options.
+    ext = extension.Flake8Extension
+    ext.options = options
+    try:
+        yield ext
+    finally:
+        ext.options = None
+
+
 class TestFlake8Extension(base.BaseTest):
 
     def test_flake8_extension_empty(self):
@@ -67,6 +93,58 @@ def test_flake8_extension_basic(self):
 
         assert result == expected
 
+    def test_flake8_extension_get_linter_classes_select(self):
+        options = create_options(select=["DUO101"])
+
+        with extension_with_options(options) as ext:
+            result = ext.get_linter_classes()
+
+        expected = (extension.dlint.linters.YieldReturnStatementLinter,)
+
+        assert result == expected
+
+    def test_flake8_extension_get_linter_classes_extended_default_select(self):
+        options = create_options(extended_default_select=["DUO101"])
+
+        with extension_with_options(options) as ext:
+            result = ext.get_linter_classes()
+
+        expected = (extension.dlint.linters.YieldReturnStatementLinter,)
+
+        assert result == expected
+
+    def test_flake8_extension_get_linter_classes_ignore(self):
+        options = create_options(ignore=["DUO101"])
+
+        with extension_with_options(options) as ext:
+            result = ext.get_linter_classes()
+
+        expected = list(extension.dlint.linters.ALL)
+        expected.remove(extension.dlint.linters.YieldReturnStatementLinter)
+        expected = tuple(expected)
+
+        assert result == expected
+
+    def test_flake8_extension_get_linter_classes_extend_ignore(self):
+        options = create_options(extend_ignore=["DUO101"])
+
+        with extension_with_options(options) as ext:
+            result = ext.get_linter_classes()
+
+        expected = list(extension.dlint.linters.ALL)
+        expected.remove(extension.dlint.linters.YieldReturnStatementLinter)
+        expected = tuple(expected)
+
+        assert result == expected
+
+    def test_flake8_extension_get_linter_classes_missing_options(self):
+        ext = extension.Flake8Extension
+
+        result = ext.get_linter_classes()
+        expected = extension.dlint.linters.ALL
+
+        assert result == expected
+
 
 if __name__ == "__main__":
     unittest.main()