Merged in feature/mypy-lint (pull request #56)

Add mypy linter

.gitignore

@@ -68,3 +68,5 @@ docs/_build/
 
 # Vagrant
 .vagrant/
+
+.mypy_cache/

badwolf/lint/linters/mypy.py

@@ -0,0 +1,48 @@
+# -*- coding: utf-8 -*-
+import logging
+
+from badwolf.utils import run_command
+from badwolf.lint import Problem
+from badwolf.lint.linters import PythonLinter
+from badwolf.lint.utils import in_path
+
+
+logger = logging.getLogger(__name__)
+
+
+class MypyLinter(PythonLinter):
+    name = 'mypy'
+    default_pattern = '*.py *.pyi'
+
+    def is_usable(self):
+        if not in_path('mypy'):
+            return False
+
+        # mypy only avaiable in Python 3
+        python_version = self.python_name[6:]
+        major, *_ = python_version.split('.', 1)
+        if int(major) < 3:
+            return False
+        return True
+
+    def lint_files(self, files):
+        command = [
+            self.python_name,
+            '-m',
+            'mypy',
+        ]
+        command += files
+        _, output = run_command(command, split=True, include_errors=True, cwd=self.working_dir)
+        if not output:
+            raise StopIteration()
+
+        for line in output:
+            filename, line, level, message = self._parse_line(line)
+            is_error = level == 'error'
+            yield Problem(filename, line, message, self.name, is_error=is_error)
+
+    def _parse_line(self, line):
+        """mypy only generates results as stdout.
+        Parse the output for real data."""
+        parts = line.split(':', 3)
+        return parts[0], int(parts[1]), parts[2].strip(), parts[3].strip()

badwolf/lint/processor.py

@@ -20,6 +20,7 @@
 from badwolf.lint.linters.pylint import PylintLinter
 from badwolf.lint.linters.sasslint import SassLinter
 from badwolf.lint.linters.stylelint import StyleLinter
+from badwolf.lint.linters.mypy import MypyLinter
 
 
 logger = logging.getLogger(__name__)
@@ -40,6 +41,7 @@ class LintProcessor(object):
         'pylint': PylintLinter,
         'sasslint': SassLinter,
         'stylelint': StyleLinter,
+        'mypy': MypyLinter,
     }
 
     def __init__(self, context, spec, working_dir=None):

requirements.txt

@@ -25,3 +25,4 @@ marshmallow-oneofschema
 twine
 flake8-bugbear
 is-minified-js
+mypy

tests/fixtures/mypy/a.py

@@ -0,0 +1,5 @@
+def p() -> None:
+    print('hello')
+
+
+a = p()

tests/test_lint.py

@@ -815,3 +815,47 @@ def test_stylelint_lint_a_scss(app, caplog):
     assert len(lint.problems) == 2
     problem = lint.problems[0]
     assert problem.filename == 'a.scss'
+
+
+def test_mypy_lint_a_py(app, caplog):
+    diff = """diff --git a/a.py b/a.py
+new file mode 100644
+index 0000000..87604af
+--- /dev/null
++++ b/a.py
+@@ -0,0 +1,5 @@
++def p() -> None:
++    print('hello')
++
++
++a = p()
+"""
+
+    context = Context(
+        'deepanalyzer/badwolf',
+        None,
+        'pullrequest',
+        'message',
+        {'commit': {'hash': '000000'}},
+        {'commit': {'hash': '111111'}},
+        pr_id=1
+    )
+    spec = Specification()
+    spec.linters.append(ObjectDict(name='mypy', pattern=None))
+    lint = LintProcessor(context, spec, os.path.join(FIXTURES_PATH, 'mypy'))
+    patch = PatchSet(diff.split('\n'))
+    with mock.patch.object(lint, 'load_changes') as load_changes,\
+            mock.patch.object(lint, 'update_build_status') as build_status,\
+            mock.patch.object(lint, '_report') as report:
+        load_changes.return_value = patch
+        build_status.return_value = None
+        report.return_value = (1, 2)
+        lint.problems.set_changes(patch)
+        lint.process()
+
+        assert load_changes.called
+
+    assert len(lint.problems) == 1
+    problem = lint.problems[0]
+    assert problem.line == 5
+    assert problem.filename == 'a.py'