fix: handle blank lines after class definition properly (#142)

* fix: no longer remove blank lines when no class docstring

* test: add tests for class and blank lines

.sourcery.yaml

@@ -0,0 +1,67 @@
+# 🪄 This is your project's Sourcery configuration file.
+
+# You can use it to get Sourcery working in the way you want, such as
+# ignoring specific refactorings, skipping directories in your project,
+# or writing custom rules.
+
+# 📚 For a complete reference to this file, see the documentation at
+# https://docs.sourcery.ai/Configuration/Project-Settings/
+
+# This file was auto-generated by Sourcery on 2022-12-28 at 22:39.
+
+version: '1'  # The schema version of this config file
+
+ignore: # A list of paths or files which Sourcery will ignore.
+- .git
+- venv
+- .venv
+- env
+- .env
+- .tox
+
+# rule_settings:
+#  enable:
+#  - default
+#  disable: []  # A list of rule IDs Sourcery will never suggest.
+#  rule_types:
+#  - refactoring
+#  - suggestion
+#  - comment
+#  python_version: '3.9' # A string specifying the lowest Python version your project supports. Sourcery will not suggest refactorings requiring a higher Python version.
+
+# rules:  # A list of custom rules Sourcery will include in its analysis.
+# - id: no-print-statements
+#   description: Do not use print statements in the test directory.
+#   pattern: print(...)
+#   replacement:
+#   condition:
+#   explanation:
+#   paths:
+#     include:
+#     - test
+#     exclude:
+#     - conftest.py
+#   tests: []
+#   tags: []
+
+# rule_tags: {} # Additional rule tags.
+
+# metrics:
+#   quality_threshold: 25.0
+
+# github:
+#   labels: []
+#   ignore_labels:
+#   - sourcery-ignore
+#   request_review: author
+#   sourcery_branch: sourcery/{base_branch}
+
+# clone_detection:
+#   min_lines: 3
+#   min_duplicates: 2
+#   identical_clones_only: false
+
+# proxy:
+#   url:
+#   ssl_certs_file:
+#   no_ssl_verify: false

src/docformatter/format.py

@@ -313,24 +313,26 @@ def _format_code(
 
                 # If the current token is a newline, the previous token was a
                 # newline or a comment, and these two sequential newlines
-                # follow a function definition, ignore the blank line.
+                # follow a function or method definition, ignore the blank
+                # line before the docstring.
                 if (
                     len(modified_tokens) <= 2
                     or token_type not in {tokenize.NL, tokenize.NEWLINE}
                     or modified_tokens[-1][0]
                     not in {tokenize.NL, tokenize.NEWLINE}
                     or modified_tokens[-2][1] != ":"
                     and modified_tokens[-2][0] != tokenize.COMMENT
-                    or not modified_tokens[-2][4]
-                    .lstrip()
-                    .startswith(("def", "class"))
+                    or not modified_tokens[-2][4].lstrip().startswith(("def"))
                 ):
                     modified_tokens.append(
                         (token_type, token_string, start, end, line)
                     )
                     modified_tokens = self._do_remove_blank_lines_after_method(
                         modified_tokens
                     )
+                    modified_tokens = self._do_remove_blank_lines_before_class(
+                        modified_tokens
+                    )
 
             return untokenize.untokenize(modified_tokens)
         except tokenize.TokenError:
@@ -450,7 +452,8 @@ def _do_format_docstring(
                 ).strip()
                 return f"{beginning}{summary_wrapped}{ending}"
 
-    def _do_remove_blank_lines_after_method(self, modified_tokens):
+    @staticmethod
+    def _do_remove_blank_lines_after_method(modified_tokens):
         """Remove blank lines after method docstring.
 
         Parameters
@@ -467,12 +470,38 @@ def _do_remove_blank_lines_after_method(self, modified_tokens):
         with contextlib.suppress(IndexError):
             if (
                 modified_tokens[-1][4] == "\n"
-                and modified_tokens[-2][4].strip() == '"""'
+                and modified_tokens[-2][4].lstrip().startswith('"""')
                 and modified_tokens[-5][4].lstrip().startswith("def")
             ):
                 modified_tokens.pop(-1)
         return modified_tokens
 
+    @staticmethod
+    def _do_remove_blank_lines_before_class(modified_tokens):
+        """Remove blank lines before class docstring.
+
+        If there is no class docstring, leave any blank lines as is.
+
+        Parameters
+        ----------
+        modified_tokens: list
+            The list of tokens created from the docstring.
+
+        Returns
+        -------
+        modified_tokens: list
+            The list of tokens with any blank lines following a method
+            docstring removed.
+        """
+        with contextlib.suppress(IndexError):
+            if (
+                modified_tokens[-3][4] == "\n"
+                and modified_tokens[-2][4].lstrip().startswith('"""')
+                and modified_tokens[-6][4].lstrip().startswith("class")
+            ):
+                modified_tokens.pop(-3)
+        return modified_tokens
+
     def _do_strip_docstring(self, docstring: str) -> Tuple[str, str]:
         """Return contents of docstring and opening quote type.
 

tests/test_format_code.py

@@ -944,6 +944,70 @@ class TestClass:
 '''
         )
 
+    @pytest.mark.unit
+    @pytest.mark.parametrize("args", [[""]])
+    def test_format_code_class_docstring_remove_blank_line(
+        self, test_args, args
+    ):
+        """Remove blank line before class docstring.
+
+        See issue #139.
+        """
+        uut = Formatter(
+            test_args,
+            sys.stderr,
+            sys.stdin,
+            sys.stdout,
+        )
+
+        docstring = '''\
+class TestClass:
+    """This is a class docstring.
+
+    :cvar test_int: a class attribute.
+    ..py.method: big_method()
+    """
+'''
+        assert docstring == uut._do_format_code(
+            '''\
+class TestClass:
+
+    """This is a class docstring.
+    :cvar test_int: a class attribute.
+    ..py.method: big_method()
+    """
+'''
+        )
+
+    @pytest.mark.unit
+    @pytest.mark.parametrize("args", [[""]])
+    def test_format_code_class_docstring_keep_blank_line(
+        self, test_args, args
+    ):
+        """Keep blank line after class definition if there is no docstring.
+
+        See issue #139.
+        """
+        uut = Formatter(
+            test_args,
+            sys.stderr,
+            sys.stdin,
+            sys.stdout,
+        )
+
+        docstring = """\
+class TestClass:
+
+    variable = 1
+"""
+        assert docstring == uut._do_format_code(
+            """\
+class TestClass:
+
+    variable = 1
+"""
+        )
+
     @pytest.mark.unit
     @pytest.mark.parametrize("args", [[""]])
     def test_format_code_strip_blank_line_after_method_docstring(
@@ -989,7 +1053,7 @@ def test_method(self):
 
         pass
 '''
-)
+        )
 
 
 class TestFormatCodeRanges: