AttributeError: 'NoneType' object has no attribute 'lineno'

[mirrorrim]

Bug report

What's wrong

When I run flake8 with wemake-python-styleguide 0.6.2, I see exception traceback.
Something simular to #423

traceback

multiprocessing.pool.RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/usr/lib/python3.7/multiprocessing/pool.py", line 121, in worker
    result = (True, func(*args, **kwds))
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/checker.py", line 682, in _run_checks
    return checker.run_checks()
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/checker.py", line 612, in run_checks
    self.run_ast_checks()
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/checker.py", line 520, in run_ast_checks
    for (line_number, offset, text, check) in runner:
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/checker.py", line 178, in run
    yield from self._run_checks(self.visitors)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/checker.py", line 166, in _run_checks
    visitor.run()
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/visitors/base.py", line 140, in run
    self.visit(self.tree)
  File "/usr/lib/python3.7/ast.py", line 262, in visit
    return visitor(node)
  File "/usr/lib/python3.7/ast.py", line 270, in generic_visit
    self.visit(item)
  File "/usr/lib/python3.7/ast.py", line 262, in visit
    return visitor(node)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/visitors/ast/statements.py", line 237, in visit_ClassDef
    self.generic_visit(node)
  File "/usr/lib/python3.7/ast.py", line 270, in generic_visit
    self.visit(item)
  File "/usr/lib/python3.7/ast.py", line 262, in visit
    return visitor(node)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/visitors/ast/statements.py", line 231, in visit_any_function
    self.generic_visit(node)
  File "/usr/lib/python3.7/ast.py", line 270, in generic_visit
    self.visit(item)
  File "/usr/lib/python3.7/ast.py", line 262, in visit
    return visitor(node)
  File "/usr/lib/python3.7/ast.py", line 272, in generic_visit
    self.visit(value)
  File "/usr/lib/python3.7/ast.py", line 262, in visit
    return visitor(node)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/visitors/ast/statements.py", line 219, in visit_collection
    self._check_indentation(node, elements, extra_lines=1)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/visitors/ast/statements.py", line 206, in _check_indentation
    extra_lines,
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/wemake_python_styleguide/visitors/ast/statements.py", line 171, in _check_first_element
    if statement.lineno == node.lineno and not extra_lines:
AttributeError: 'NoneType' object has no attribute 'lineno'
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/bin/flake8", line 11, in <module>
    sys.exit(main())
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/main/cli.py", line 16, in main
    app.run(argv)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/main/application.py", line 412, in run
    self._run(argv)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/main/application.py", line 400, in _run
    self.run_checks()
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/main/application.py", line 318, in run_checks
    self.file_checker_manager.run()
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8_per_file_ignores.py", line 33, in run
    orig_run(self)
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/checker.py", line 338, in run
    self.run_parallel()
  File "/home/developer2/.local/share/virtualenvs/backend-0eAQt0K2/lib/python3.7/site-packages/flake8/checker.py", line 302, in run_parallel
    for ret in pool_map:
  File "/usr/lib/python3.7/multiprocessing/pool.py", line 774, in next
    raise value
AttributeError: 'NoneType' object has no attribute 'lineno'

Code sample that causes this issue

class Mapper:
    @property
    def section(self):
        return {
            **self.phone,
            **self.workdays
        }

System information

flake8 information

{
  "dependencies": [
    {
      "dependency": "setuptools",
      "version": "40.6.2"
    }
  ],
  "platform": {
    "python_implementation": "CPython",
    "python_version": "3.7.1",
    "system": "Linux"
  },
  "plugins": [
    {
      "is_local": false,
      "plugin": "flake8-bandit",
      "version": "v1.0.2"
    },
    {
      "is_local": false,
      "plugin": "flake8-broken-line",
      "version": "0.1.0"
    },
    {
      "is_local": false,
      "plugin": "flake8-bugbear",
      "version": "18.8.0"
    },
    {
      "is_local": false,
      "plugin": "flake8-comprehensions",
      "version": "1.4.1"
    },
    {
      "is_local": false,
      "plugin": "flake8-debugger",
      "version": "3.1.0"
    },
    {
      "is_local": false,
      "plugin": "flake8-docstrings",
      "version": "1.3.0, pydocstyle: 3.0.0"
    },
    {
      "is_local": false,
      "plugin": "flake8-eradicate",
      "version": "0.1.1"
    },
    {
      "is_local": false,
      "plugin": "flake8-print",
      "version": "3.1.0"
    },
    {
      "is_local": false,
      "plugin": "flake8-string-format",
      "version": "0.2.3"
    },
    {
      "is_local": false,
      "plugin": "flake8-type-annotations",
      "version": "0.1.0"
    },
    {
      "is_local": false,
      "plugin": "flake8_builtins",
      "version": "1.4.1"
    },
    {
      "is_local": false,
      "plugin": "flake8_coding",
      "version": "1.3.1"
    },
    {
      "is_local": false,
      "plugin": "flake8_commas",
      "version": "2.0.0"
    },
    {
      "is_local": false,
      "plugin": "flake8_isort",
      "version": "2.3"
    },
    {
      "is_local": false,
      "plugin": "flake8_pep3101",
      "version": "1.2.1"
    },
    {
      "is_local": false,
      "plugin": "flake8_quotes",
      "version": "1.0.0"
    },
    {
      "is_local": false,
      "plugin": "logging-format",
      "version": "0.5.0"
    },
    {
      "is_local": false,
      "plugin": "mccabe",
      "version": "0.6.1"
    },
    {
      "is_local": false,
      "plugin": "naming",
      "version": "0.7.0"
    },
    {
      "is_local": false,
      "plugin": "per-file-ignores",
      "version": "0.6"
    },
    {
      "is_local": false,
      "plugin": "pycodestyle",
      "version": "2.4.0"
    },
    {
      "is_local": false,
      "plugin": "pyflakes",
      "version": "2.0.0"
    },
    {
      "is_local": false,
      "plugin": "wemake-python-styleguide",
      "version": "0.6.2"
    }
  ],
  "version": "3.6.0"
}

[sobolevn]

@mirrorrim thanks for your report. New version with the fix will be released soon.

[sobolevn]

@mirrorrim please, test how 0.6.3 works for you. Any bugs are welcome! 👍

[mirrorrim]

It works now, thanks!