Mark some pyflakes flakes as errors (#297)

* Mark some pyflakes flakes as errors

* linting

Author: gatesn

pyls/plugins/pyflakes_lint.py

@@ -1,7 +1,22 @@
 # Copyright 2017 Palantir Technologies, Inc.
-from pyflakes import api as pyflakes_api
+from pyflakes import api as pyflakes_api, messages
 from pyls import hookimpl, lsp
 
+# Pyflakes messages that should be reported as Errors instead of Warns
+PYFLAKES_ERROR_MESSAGES = (
+    messages.UndefinedName,
+    messages.UndefinedExport,
+    messages.UndefinedLocal,
+    messages.DuplicateArgument,
+    messages.FutureFeatureNotDefined,
+    messages.ReturnOutsideFunction,
+    messages.YieldOutsideFunction,
+    messages.ContinueOutsideLoop,
+    messages.BreakOutsideLoop,
+    messages.ContinueInFinally,
+    messages.TwoStarredExpressions,
+)
+
 
 @hookimpl
 def pyls_lint(document):
@@ -37,9 +52,16 @@ def flake(self, message):
             'start': {'line': message.lineno - 1, 'character': message.col},
             'end': {'line': message.lineno - 1, 'character': len(self.lines[message.lineno - 1])},
         }
+
+        severity = lsp.DiagnosticSeverity.Warning
+        for message_type in PYFLAKES_ERROR_MESSAGES:
+            if isinstance(message, message_type):
+                severity = lsp.DiagnosticSeverity.Error
+                break
+
         self.diagnostics.append({
             'source': 'pyflakes',
             'range': err_range,
             'message': message.message % message.message_args,
-            'severity': lsp.DiagnosticSeverity.Warning
+            'severity': severity
         })

setup.py

@@ -40,7 +40,7 @@
         'mccabe',
         'pycodestyle',
         'pydocstyle>=2.0.0',
-        'pyflakes',
+        'pyflakes>=1.6.0',
         'rope>=0.10.5',
         'yapf',
         'pluggy'

test/plugins/test_pyflakes_lint.py

@@ -1,5 +1,5 @@
 # Copyright 2017 Palantir Technologies, Inc.
-from pyls import uris
+from pyls import lsp, uris
 from pyls.workspace import Document
 from pyls.plugins import pyflakes_lint
 
@@ -16,6 +16,8 @@ def hello():
     pass
 """
 
+DOC_UNDEFINED_NAME_ERR = "a = b"
+
 
 def test_pyflakes():
     doc = Document(DOC_URI, DOC)
@@ -26,6 +28,7 @@ def test_pyflakes():
     unused_import = [d for d in diags if d['message'] == msg][0]
 
     assert unused_import['range']['start'] == {'line': 0, 'character': 0}
+    assert unused_import['severity'] == lsp.DiagnosticSeverity.Warning
 
 
 def test_syntax_error_pyflakes():
@@ -34,3 +37,13 @@ def test_syntax_error_pyflakes():
 
     assert diag['message'] == 'invalid syntax'
     assert diag['range']['start'] == {'line': 0, 'character': 12}
+    assert diag['severity'] == lsp.DiagnosticSeverity.Error
+
+
+def test_undefined_name_pyflakes():
+    doc = Document(DOC_URI, DOC_UNDEFINED_NAME_ERR)
+    diag = pyflakes_lint.pyls_lint(doc)[0]
+
+    assert diag['message'] == 'undefined name \'b\''
+    assert diag['range']['start'] == {'line': 0, 'character': 4}
+    assert diag['severity'] == lsp.DiagnosticSeverity.Error