Add DiagnosticTag support (#229)

Author: krassowski

pylsp/plugins/flake8_lint.py

@@ -13,6 +13,13 @@
 
 log = logging.getLogger(__name__)
 FIX_IGNORES_RE = re.compile(r'([^a-zA-Z0-9_,]*;.*(\W+||$))')
+UNNECESSITY_CODES = {
+    'F401',  # `module` imported but unused
+    'F504',  # % format unused named arguments
+    'F522',  # .format(...) unused named arguments
+    'F523',  # .format(...) unused positional arguments
+    'F841'   # local variable `name` is assigned to but never used
+}
 
 
 @hookimpl
@@ -176,24 +183,25 @@ def parse_stdout(document, stdout):
         severity = lsp.DiagnosticSeverity.Warning
         if code == "E999" or code[0] == "F":
             severity = lsp.DiagnosticSeverity.Error
-        diagnostics.append(
-            {
-                'source': 'flake8',
-                'code': code,
-                'range': {
-                    'start': {
-                        'line': line,
-                        'character': character
-                    },
-                    'end': {
-                        'line': line,
-                        # no way to determine the column
-                        'character': len(document.lines[line])
-                    }
+        diagnostic = {
+            'source': 'flake8',
+            'code': code,
+            'range': {
+                'start': {
+                    'line': line,
+                    'character': character
                 },
-                'message': msg,
-                'severity': severity,
-            }
-        )
+                'end': {
+                    'line': line,
+                    # no way to determine the column
+                    'character': len(document.lines[line])
+                }
+            },
+            'message': msg,
+            'severity': severity,
+        }
+        if code in UNNECESSITY_CODES:
+            diagnostic['tags'] = [lsp.DiagnosticTag.Unnecessary]
+        diagnostics.append(diagnostic)
 
     return diagnostics

pylsp/plugins/pycodestyle_lint.py

@@ -75,14 +75,17 @@ def error(self, line_number, offset, text, check):
                 'character': 100 if line_number > len(self.lines) else len(self.lines[line_number - 1])
             },
         }
-        self.diagnostics.append({
+        diagnostic = {
             'source': 'pycodestyle',
             'range': err_range,
             'message': text,
             'code': code,
             # Are style errors really ever errors?
             'severity': _get_severity(code)
-        })
+        }
+        if code.startswith('W6'):
+            diagnostic['tags'] = [lsp.DiagnosticTag.Deprecated]
+        self.diagnostics.append(diagnostic)
 
 
 def _get_severity(code):

pylsp/plugins/pylint_lint.py

@@ -28,6 +28,20 @@
 # fix for a very specific upstream issue.
 # Related: https://github.com/PyCQA/pylint/issues/3518
 os.environ['PYGAME_HIDE_SUPPORT_PROMPT'] = 'hide'
+DEPRECATION_CODES = {
+    'W0402',  # Uses of a deprecated module %r
+    'W1505',  # Using deprecated method %s()
+    'W1511',  # Using deprecated argument %s of method %s()
+    'W1512',  # Using deprecated class %s of module %s
+    'W1513',  # Using deprecated decorator %s()
+}
+UNNECESSITY_CODES = {
+    'W0611',  # Unused import %s
+    'W0612',  # Unused variable %r
+    'W0613',  # Unused argument %r
+    'W0614',  # Unused import %s from wildcard import
+    'W1304',  # Unused-format-string-argument
+}
 
 
 class PylintLinter:
@@ -146,13 +160,22 @@ def lint(cls, document, is_saved, flags=''):
             elif diag['type'] == 'warning':
                 severity = lsp.DiagnosticSeverity.Warning
 
-            diagnostics.append({
+            code = diag['message-id']
+
+            diagnostic = {
                 'source': 'pylint',
                 'range': err_range,
                 'message': '[{}] {}'.format(diag['symbol'], diag['message']),
                 'severity': severity,
-                'code': diag['message-id']
-            })
+                'code': code
+            }
+
+            if code in UNNECESSITY_CODES:
+                diagnostic['tags'] = [lsp.DiagnosticTag.Unnecessary]
+            if code in DEPRECATION_CODES:
+                diagnostic['tags'] = [lsp.DiagnosticTag.Deprecated]
+
+            diagnostics.append(diagnostic)
         cls.last_diags[document.path] = diagnostics
         return diagnostics
 
@@ -295,24 +318,27 @@ def _parse_pylint_stdio_result(document, stdout):
             'W': lsp.DiagnosticSeverity.Warning,
         }
         severity = severity_map[code[0]]
-        diagnostics.append(
-            {
-                'source': 'pylint',
-                'code': code,
-                'range': {
-                    'start': {
-                        'line': line,
-                        'character': character
-                    },
-                    'end': {
-                        'line': line,
-                        # no way to determine the column
-                        'character': len(document.lines[line]) - 1
-                    }
+        diagnostic = {
+            'source': 'pylint',
+            'code': code,
+            'range': {
+                'start': {
+                    'line': line,
+                    'character': character
                 },
-                'message': msg,
-                'severity': severity,
-            }
-        )
+                'end': {
+                    'line': line,
+                    # no way to determine the column
+                    'character': len(document.lines[line]) - 1
+                }
+            },
+            'message': msg,
+            'severity': severity,
+        }
+        if code in UNNECESSITY_CODES:
+            diagnostic['tags'] = [lsp.DiagnosticTag.Unnecessary]
+        if code in DEPRECATION_CODES:
+            diagnostic['tags'] = [lsp.DiagnosticTag.Deprecated]
+        diagnostics.append(diagnostic)
 
     return diagnostics

test/plugins/test_flake8_lint.py

@@ -40,6 +40,7 @@ def test_flake8_unsaved(workspace):
     assert unused_var['range']['start'] == {'line': 5, 'character': 1}
     assert unused_var['range']['end'] == {'line': 5, 'character': 11}
     assert unused_var['severity'] == lsp.DiagnosticSeverity.Error
+    assert unused_var['tags'] == [lsp.DiagnosticTag.Unnecessary]
 
 
 def test_flake8_lint(workspace):

test/plugins/test_pylint_lint.py

@@ -51,6 +51,7 @@ def test_pylint(config, workspace):
 
         assert unused_import['range']['start'] == {'line': 0, 'character': 0}
         assert unused_import['severity'] == lsp.DiagnosticSeverity.Warning
+        assert unused_import['tags'] == [lsp.DiagnosticTag.Unnecessary]
 
         if IS_PY3:
             # test running pylint in stdin
@@ -79,6 +80,7 @@ def test_syntax_error_pylint_py3(config, workspace):
         # Pylint doesn't give column numbers for invalid syntax.
         assert diag['range']['start'] == {'line': 0, 'character': 12}
         assert diag['severity'] == lsp.DiagnosticSeverity.Error
+        assert 'tags' not in diag
 
         # test running pylint in stdin
         config.plugin_settings('pylint')['executable'] = 'pylint'