Elaborate on Python support policy (#2819)

[etc/vim.git] / src / black / lines.py

diff --git a/src/black/lines.py b/src/black/lines.py
index 63225c0e6d31288bd7c68004e751eb05ca537382..7d50f02aebc16b1787239dcf3f41625464b29dc5 100644 (file)
--- a/src/black/lines.py
+++ b/src/black/lines.py
@@ -277,7 +277,9 @@ class Line:
         if self.is_import:
             return True
 
-        if not is_one_tuple_between(closing.opening_bracket, closing, self.leaves):
+        if closing.opening_bracket is not None and not is_one_tuple_between(
+            closing.opening_bracket, closing, self.leaves
+        ):
             return True
 
         return False
@@ -447,11 +449,38 @@ class EmptyLineTracker:
             before = 0
         depth = current_line.depth
         while self.previous_defs and self.previous_defs[-1] >= depth:
-            self.previous_defs.pop()
             if self.is_pyi:
-                before = 0 if depth else 1
+                assert self.previous_line is not None
+                if depth and not current_line.is_def and self.previous_line.is_def:
+                    # Empty lines between attributes and methods should be preserved.
+                    before = min(1, before)
+                elif depth:
+                    before = 0
+                else:
+                    before = 1
             else:
-                before = 1 if depth else 2
+                if depth:
+                    before = 1
+                elif (
+                    not depth
+                    and self.previous_defs[-1]
+                    and current_line.leaves[-1].type == token.COLON
+                    and (
+                        current_line.leaves[0].value
+                        not in ("with", "try", "for", "while", "if", "match")
+                    )
+                ):
+                    # We shouldn't add two newlines between an indented function and
+                    # a dependent non-indented clause. This is to avoid issues with
+                    # conditional function definitions that are technically top-level
+                    # and therefore get two trailing newlines, but look weird and
+                    # inconsistent when they're followed by elif, else, etc. This is
+                    # worse because these functions only get *one* preceding newline
+                    # already.
+                    before = 1
+                else:
+                    before = 2
+            self.previous_defs.pop()
         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)
 
@@ -502,9 +531,11 @@ class EmptyLineTracker:
 
         if self.is_pyi:
             if self.previous_line.depth > current_line.depth:
-                newlines = 1
+                newlines = 0 if current_line.depth else 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:
+                if current_line.depth:
+                    newlines = 0
+                elif current_line.is_stub_class and self.previous_line.is_stub_class:
                     # No blank line between classes with an empty body
                     newlines = 0
                 else:
@@ -512,15 +543,18 @@ class EmptyLineTracker:
             elif (
                 current_line.is_def or current_line.is_decorator
             ) and not self.previous_line.is_def:
-                # Blank line between a block of functions (maybe with preceding
-                # decorators) and a block of non-functions
-                newlines = 1
+                if current_line.depth:
+                    # In classes empty lines between attributes and methods should
+                    # be preserved.
+                    newlines = min(1, before)
+                else:
+                    # Blank line between a block of functions (maybe with preceding
+                    # decorators) and a block of non-functions
+                    newlines = 1
             else:
                 newlines = 0
         else:
-            newlines = 2
-        if current_line.depth and newlines:
-            newlines -= 1
+            newlines = 1 if current_line.depth else 2
         return newlines, 0