From 9db828c3def8f23f0d9e8650a7d2b009c8043eaf Mon Sep 17 00:00:00 2001
From: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Date: Sat, 16 Jun 2018 11:53:45 -0700
Subject: [PATCH] Add blank line after constants in stub file (#360)

Fixes #340
---
 black.py            | 84 +++++++++++++++++++++++++--------------------
 tests/data/stub.pyi |  8 +++++
 2 files changed, 54 insertions(+), 38 deletions(-)

diff --git a/black.py b/black.py
index e3b3882..dcc37a5 100644
--- a/black.py
+++ b/black.py
@@ -1390,44 +1390,8 @@ class EmptyLineTracker:
                 before = 0 if depth else 1
             else:
                 before = 1 if depth else 2
-        is_decorator = current_line.is_decorator
-        if is_decorator or current_line.is_def or current_line.is_class:
-            if not is_decorator:
-                self.previous_defs.append(depth)
-            if self.previous_line is None:
-                # Don't insert empty lines before the first line in the file.
-                return 0, 0
-
-            if self.previous_line.is_decorator:
-                return 0, 0
-
-            if self.previous_line.depth < current_line.depth and (
-                self.previous_line.is_class or self.previous_line.is_def
-            ):
-                return 0, 0
-
-            if (
-                self.previous_line.is_comment
-                and self.previous_line.depth == current_line.depth
-                and before == 0
-            ):
-                return 0, 0
-
-            if self.is_pyi:
-                if self.previous_line.depth > current_line.depth:
-                    newlines = 1
-                elif current_line.is_class or self.previous_line.is_class:
-                    if current_line.is_stub_class and self.previous_line.is_stub_class:
-                        newlines = 0
-                    else:
-                        newlines = 1
-                else:
-                    newlines = 0
-            else:
-                newlines = 2
-            if current_line.depth and newlines:
-                newlines -= 1
-            return newlines, 0
+        if current_line.is_decorator or current_line.is_def or current_line.is_class:
+            return self._maybe_empty_lines_for_class_or_def(current_line, before)
 
         if (
             self.previous_line
@@ -1446,6 +1410,50 @@ class EmptyLineTracker:
 
         return before, 0
 
+    def _maybe_empty_lines_for_class_or_def(
+        self, current_line: Line, before: int
+    ) -> Tuple[int, int]:
+        if not current_line.is_decorator:
+            self.previous_defs.append(current_line.depth)
+        if self.previous_line is None:
+            # Don't insert empty lines before the first line in the file.
+            return 0, 0
+
+        if self.previous_line.is_decorator:
+            return 0, 0
+
+        if self.previous_line.depth < current_line.depth and (
+            self.previous_line.is_class or self.previous_line.is_def
+        ):
+            return 0, 0
+
+        if (
+            self.previous_line.is_comment
+            and self.previous_line.depth == current_line.depth
+            and before == 0
+        ):
+            return 0, 0
+
+        if self.is_pyi:
+            if self.previous_line.depth > current_line.depth:
+                newlines = 1
+            elif current_line.is_class or self.previous_line.is_class:
+                if current_line.is_stub_class and self.previous_line.is_stub_class:
+                    # No blank line between classes with an emty body
+                    newlines = 0
+                else:
+                    newlines = 1
+            elif current_line.is_def and not self.previous_line.is_def:
+                # Blank line between a block of functions and a block of non-functions
+                newlines = 1
+            else:
+                newlines = 0
+        else:
+            newlines = 2
+        if current_line.depth and newlines:
+            newlines -= 1
+        return newlines, 0
+
 
 @dataclass
 class LineGenerator(Visitor[Line]):
diff --git a/tests/data/stub.pyi b/tests/data/stub.pyi
index 986cc84..94ba852 100644
--- a/tests/data/stub.pyi
+++ b/tests/data/stub.pyi
@@ -1,3 +1,7 @@
+X: int
+
+def f(): ...
+
 class C:
     ...
 
@@ -16,6 +20,10 @@ def g():
 def h(): ...
 
 # output
+X: int
+
+def f(): ...
+
 class C: ...
 class B: ...
 
-- 
2.39.5