Fix dedent definition for search function end (#2534)

* Test and fix

* fix noqa tests

* change type and test input name

tests/test_visitors/test_ast/test_classes/test_wrong_empty_lines_count.py

@@ -190,7 +190,7 @@ def test_wrong(
     assert_errors(visitor, [WrongEmptyLinesCountViolation])
 
 
-@pytest.mark.parametrize('input_', [
+@pytest.mark.parametrize('template', [
     class_with_valid_method,
     allow_function,
     allow_function_with_comments,
@@ -202,14 +202,14 @@ def test_wrong(
     module_level_empty_lines,
 ])
 def test_success(
-    input_,
+    template,
     parse_tokens,
     default_options,
     assert_errors,
     mode,
 ):
     """Testing available cases."""
-    file_tokens = parse_tokens(mode(input_))
+    file_tokens = parse_tokens(mode(template))
 
     visitor = WrongEmptyLinesCountVisitor(
         default_options, file_tokens=file_tokens,
@@ -235,15 +235,20 @@ def test_zero_option(
     assert_errors(visitor, [WrongEmptyLinesCountViolation])
 
 
+@pytest.mark.parametrize('template', [
+    class_with_valid_method,
+    file_with_few_class,
+])
 def test_zero_option_with_valid_method(
+    template,
     parse_tokens,
     default_options,
     assert_errors,
     options,
     mode,
 ):
     """Test zero configuration with valid method."""
-    file_tokens = parse_tokens(mode(class_with_valid_method))
+    file_tokens = parse_tokens(mode(template))
     visitor = WrongEmptyLinesCountVisitor(
         options(exps_for_one_empty_line=0), file_tokens=file_tokens,
     )

wemake_python_styleguide/visitors/ast/function_empty_lines.py

@@ -1,6 +1,6 @@
 import math
 import tokenize
-from typing import List
+from typing import Iterator, List
 
 from typing_extensions import final
 
@@ -26,7 +26,10 @@ def body(self) -> str:
         return ''.join([target_token.string for target_token in target_tokens])
 
     def _is_target_line(self, token: tokenize.TokenInfo) -> bool:
-        is_comment = '#' in token.line
+        stripped_token_line = token.line.strip()
+        is_comment = False
+        if stripped_token_line:
+            is_comment = '#' in stripped_token_line[0]
         is_string = token.type == tokenize.STRING
         is_multistring_end = '"""' in token.line
         return is_comment or is_string or is_multistring_end
@@ -39,30 +42,41 @@ def __init__(self, file_tokens: List[tokenize.TokenInfo]) -> None:
         self._file_tokens = file_tokens
 
     def as_list(self) -> List[_Function]:
-        functions = []
+        return list(self._search_functions())
+
+    def _search_functions(self) -> Iterator[_Function]:
         function_tokens: List[tokenize.TokenInfo] = []
         in_function = False
+        function_start_column = 0
         for token in self._file_tokens:
-            if self._is_function_start(token):
+            function_ended = self._is_function_end(
+                token,
+                bool(function_tokens),
+                function_start_column,
+            )
+            if not in_function and self._is_function_start(token):
                 in_function = True
-            elif self._is_function_end(token, bool(function_tokens)):
+                function_start_column = token.start[1]
+            elif function_ended:
                 in_function = False
-                functions.append(_Function(function_tokens))
+                function_start_column = 0
+                yield _Function(function_tokens)
                 function_tokens = []
             if in_function:
                 function_tokens.append(token)
-        return functions
 
     def _is_function_start(self, token: tokenize.TokenInfo) -> bool:
-        return token.type == tokenize.NAME and token.string == 'def'
+        return token.type == tokenize.NAME and token.string in {'def', 'async'}
 
     def _is_function_end(
         self,
         token: tokenize.TokenInfo,
         function_tokens_exists: bool,
+        function_start_column: int,
     ) -> bool:
-        is_dedent_token = token.type == tokenize.DEDENT and token.start[1] == 0
-        return is_dedent_token and function_tokens_exists
+        column_valid = token.start[1] in {0, function_start_column}
+        is_dedent_token = token.type == tokenize.DEDENT
+        return is_dedent_token and function_tokens_exists and column_valid
 
 
 @final
@@ -84,7 +98,7 @@ def analyze(self) -> List[best_practices.WrongEmptyLinesCountViolation]:
                 line for line in splitted_function_body if line == ''
             ])
             if not empty_lines_count:
-                return []
+                continue
 
             available_empty_lines = self._available_empty_lines(
                 len(splitted_function_body), empty_lines_count,