From 9c9f6eb6d53c4a38c46acfcffa1c90a787a72a77 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=C5=81ukasz=20Langa?= <lukasz@langa.pl>
Date: Fri, 16 Mar 2018 17:32:55 -0700
Subject: [PATCH] Remove the trailing comma if there is only one argument to a
 call

This makes it consistent with removing the trailing comma when multiple
arguments to a call fit in a single line. It also makes it a tiny bit more
likely that an expression will fit a line that didn't use to.
---
 README.md           |  5 +++++
 black.py            | 10 +++++++---
 tests/expression.py | 10 ++++++++--
 tests/function.py   |  4 ++--
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index c1fd95a..69616ff 100644
--- a/README.md
+++ b/README.md
@@ -260,6 +260,11 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 ### 18.3a2 (unreleased)
 
+* ignore empty bracket pairs while splitting. This avoids very weirdly
+  looking formattings (#34, #35)
+
+* remove a trailing comma if there is a single argument to a call
+
 * fixed missing space in numpy-style array indexing (#33)
 
 * fixed spurious space after star-based unary expressions (#31)
diff --git a/black.py b/black.py
index b343da7..27691dd 100644
--- a/black.py
+++ b/black.py
@@ -508,6 +508,10 @@ class Line:
             bracket_depth = leaf.bracket_depth
             if bracket_depth == depth and leaf.type == token.COMMA:
                 commas += 1
+                if leaf.parent and leaf.parent.type == syms.arglist:
+                    commas += 1
+                    break
+
         if commas > 1:
             self.leaves.pop()
             return True
@@ -1480,7 +1484,7 @@ def assert_equivalent(src: str, dst: str) -> None:
         raise AssertionError(
             f"INTERNAL ERROR: Black produced invalid code: {exc}. "
             f"Please report a bug on https://github.com/ambv/black/issues.  "
-            f"This invalid output might be helpful: {log}",
+            f"This invalid output might be helpful: {log}"
         ) from None
 
     src_ast_str = '\n'.join(_v(src_ast))
@@ -1491,7 +1495,7 @@ def assert_equivalent(src: str, dst: str) -> None:
             f"INTERNAL ERROR: Black produced code that is not equivalent to "
             f"the source.  "
             f"Please report a bug on https://github.com/ambv/black/issues.  "
-            f"This diff might be helpful: {log}",
+            f"This diff might be helpful: {log}"
         ) from None
 
 
@@ -1510,7 +1514,7 @@ def assert_stable(src: str, dst: str, line_length: int) -> None:
             f"INTERNAL ERROR: Black produced different code on the second pass "
             f"of the formatter.  "
             f"Please report a bug on https://github.com/ambv/black/issues.  "
-            f"This diff might be helpful: {log}",
+            f"This diff might be helpful: {log}"
         ) from None
 
 
diff --git a/tests/expression.py b/tests/expression.py
index 2e7f275..e7054e3 100644
--- a/tests/expression.py
+++ b/tests/expression.py
@@ -106,15 +106,15 @@ a = (1,)
 b = 1,
 c = 1
 d = (1,) + a + (2,)
+e = (1,).count(1)
 what_is_up_with_those_new_coord_names = (coord_names + set(vars_to_create)) + set(vars_to_remove)
 what_is_up_with_those_new_coord_names = (coord_names | set(vars_to_create)) - set(vars_to_remove)
-
+result = session.query(models.Customer.id).filter(models.Customer.account_id == account_id, models.Customer.email == email_address).order_by(models.Customer.id.asc(),).all()
 
 def gen():
     yield from outside_of_generator
     a = (yield)
 
-
 async def f():
     await some.complicated[0].call(with_args=(True or (1 is not 1)))
 
@@ -239,12 +239,18 @@ a = (1,)
 b = 1,
 c = 1
 d = (1,) + a + (2,)
+e = (1,).count(1)
 what_is_up_with_those_new_coord_names = (coord_names + set(vars_to_create)) + set(
     vars_to_remove
 )
 what_is_up_with_those_new_coord_names = (coord_names | set(vars_to_create)) - set(
     vars_to_remove
 )
+result = session.query(models.Customer.id).filter(
+    models.Customer.account_id == account_id, models.Customer.email == email_address
+).order_by(
+    models.Customer.id.asc()
+).all()
 
 
 def gen():
diff --git a/tests/function.py b/tests/function.py
index 29de408..7fa6866 100644
--- a/tests/function.py
+++ b/tests/function.py
@@ -37,7 +37,7 @@ def example(session):
         models.Customer.account_id == account_id,
         models.Customer.email == email_address,
     ).order_by(
-        models.Customer.id.asc(),
+        models.Customer.id.asc()
     ).all()
 def long_lines():
     if True:
@@ -129,7 +129,7 @@ def example(session):
     result = session.query(models.Customer.id).filter(
         models.Customer.account_id == account_id, models.Customer.email == email_address
     ).order_by(
-        models.Customer.id.asc(),
+        models.Customer.id.asc()
     ).all()
 
 
-- 
2.39.5