From e912c7ff54c392e92a765c5eff0bd2ca3bb05b47 Mon Sep 17 00:00:00 2001
From: Bryan Bugyi <bryanbugyi34@gmail.com>
Date: Mon, 28 Dec 2020 15:30:23 -0500
Subject: [PATCH] Fix INTERNAL ERROR caused by removing parens from pointless
 string (#1888)

Fixes #1846.
---
 src/black/__init__.py                  | 11 ++++++-
 tests/data/long_strings__regression.py | 42 ++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/src/black/__init__.py b/src/black/__init__.py
index 5f0f897..c7c5d72 100644
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -3271,7 +3271,8 @@ class StringParenStripper(StringTransformer):
 
     Requirements:
         The line contains a string which is surrounded by parentheses and:
-            - The target string is NOT the only argument to a function call).
+            - The target string is NOT the only argument to a function call.
+            - The target string is NOT a "pointless" string.
             - If the target string contains a PERCENT, the brackets are not
               preceeded or followed by an operator with higher precedence than
               PERCENT.
@@ -3295,6 +3296,14 @@ class StringParenStripper(StringTransformer):
             if leaf.type != token.STRING:
                 continue
 
+            # If this is a "pointless" string...
+            if (
+                leaf.parent
+                and leaf.parent.parent
+                and leaf.parent.parent.type == syms.simple_stmt
+            ):
+                continue
+
             # Should be preceded by a non-empty LPAR...
             if (
                 not is_valid_index(idx - 1)
diff --git a/tests/data/long_strings__regression.py b/tests/data/long_strings__regression.py
index 7065b2f..2e7f248 100644
--- a/tests/data/long_strings__regression.py
+++ b/tests/data/long_strings__regression.py
@@ -375,6 +375,27 @@ RE_THREE_BACKSLASHES = {
 print(f"Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam. {[f'{i}' for i in range(10)]}")
 x = f"This is a long string which contains an f-expr that should not split {{{[i for i in range(5)]}}}."
 
+# The parens should NOT be removed in this case.
+(
+    "my very long string that should get formatted if I'm careful to make sure it goes"
+    " over 88 characters which it has now"
+)
+
+# The parens should NOT be removed in this case.
+(
+    "my very long string that should get formatted if I'm careful to make sure it goes over 88 characters which"
+    " it has now"
+)
+
+# The parens should NOT be removed in this case.
+(
+    "my very long string"
+    " that should get formatted"
+    " if I'm careful to make sure"
+    " it goes over 88 characters which"
+    " it has now"
+)
+
 # output
 
 
@@ -844,3 +865,24 @@ x = (
     "This is a long string which contains an f-expr that should not split"
     f" {{{[i for i in range(5)]}}}."
 )
+
+# The parens should NOT be removed in this case.
+(
+    "my very long string that should get formatted if I'm careful to make sure it goes"
+    " over 88 characters which it has now"
+)
+
+# The parens should NOT be removed in this case.
+(
+    "my very long string that should get formatted if I'm careful to make sure it goes"
+    " over 88 characters which it has now"
+)
+
+# The parens should NOT be removed in this case.
+(
+    "my very long string"
+    " that should get formatted"
+    " if I'm careful to make sure"
+    " it goes over 88 characters which"
+    " it has now"
+)
-- 
2.39.5