From 3903d3401bae8115d1e92cc8954b77f6ff05dc2d Mon Sep 17 00:00:00 2001
From: Timothy Crosley <timothy.crosley@gmail.com>
Date: Tue, 1 Sep 2020 03:04:21 -0700
Subject: [PATCH] Resovle #1434 add backslash-grid mode

---
 README.md                     | 15 +++++++++++++--
 isort/wrap_modes.py           | 10 ++++++++--
 tests/unit/test_wrap_modes.py | 21 +++++++++++++++++++++
 3 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index a5564312c..6bd080430 100644
--- a/README.md
+++ b/README.md
@@ -164,7 +164,7 @@ notified.
 
 You will notice above the \"multi\_line\_output\" setting. This setting
 defines how from imports wrap when they extend past the line\_length
-limit and has 6 possible settings:
+limit and has 12 possible settings:
 
 **0 - Grid**
 
@@ -285,7 +285,18 @@ from third_party import (
     lib4, lib5, lib6)
 ```
 
-Note: to change the how constant indents appear - simply change the
+**11 - Backslash Grid**
+
+Same as Mode 0 - _Grid_ but uses backslashes instead of parentheses to group imports.
+
+```python
+from third_party import lib1, lib2, lib3, \
+                        lib4, lib5
+```
+
+## Indentation
+
+To change the how constant indents appear - simply change the
 indent property with the following accepted formats:
 
 -   Number of spaces you would like. For example: 4 would cause standard
diff --git a/isort/wrap_modes.py b/isort/wrap_modes.py
index 8e10a9474..b7b22f000 100644
--- a/isort/wrap_modes.py
+++ b/isort/wrap_modes.py
@@ -60,11 +60,11 @@ def grid(**interface):
             len(next_statement.split(interface["line_separator"])[-1]) + 1
             > interface["line_length"]
         ):
-            lines = [f"{interface['white_space']}{next_import.split(' ')[0]}"]
+            lines = [f"{white_space}{next_import.split(' ')[0]}"]
             for part in next_import.split(" ")[1:]:
                 new_line = f"{lines[-1]} {part}"
                 if len(new_line) + 1 > interface["line_length"]:
-                    lines.append(f"{interface['white_space']}{part}")
+                    lines.append(f"{white_space}{part}")
                 else:
                     lines[-1] = new_line
             next_import = interface["line_separator"].join(lines)
@@ -306,6 +306,12 @@ def hanging_indent_with_parentheses(**interface):
     return _hanging_indent_common(use_parentheses=True, **interface)
 
 
+@_wrap_mode
+def backslash_grid(**interface):
+    interface["indent"] = interface["white_space"][:-1]
+    return _hanging_indent_common(use_parentheses=False, **interface)
+
+
 WrapModes = enum.Enum(  # type: ignore
     "WrapModes", {wrap_mode: index for index, wrap_mode in enumerate(_wrap_modes.keys())}
 )
diff --git a/tests/unit/test_wrap_modes.py b/tests/unit/test_wrap_modes.py
index d27f92e77..7d6fbb0c7 100644
--- a/tests/unit/test_wrap_modes.py
+++ b/tests/unit/test_wrap_modes.py
@@ -1,5 +1,6 @@
 from hypothesis_auto import auto_pytest_magic
 
+import isort
 from isort import wrap_modes
 
 auto_pytest_magic(wrap_modes.grid, auto_allow_exceptions_=(ValueError,))
@@ -21,6 +22,7 @@
     imports=["one", "two"],
 )
 auto_pytest_magic(wrap_modes.hanging_indent_with_parentheses, auto_allow_exceptions_=(ValueError,))
+auto_pytest_magic(wrap_modes.backslash_grid, auto_allow_exceptions_=(ValueError,))
 
 
 def test_wrap_mode_interface():
@@ -65,3 +67,22 @@ def test_auto_saved():
         )
         == '*\x12\x07\U0009e994🁣"\U000ae787\x0e \x00\U0001ae99\U0005c3e7\U0004d08e \x1e  '
     )
+
+
+def test_backslash_grid():
+    """Tests the backslash_grid grid wrap mode, ensuring it matches formatting expectations.
+    See: https://github.com/PyCQA/isort/issues/1434
+    """
+    assert isort.code("""
+from kopf.engines import loggers, posting
+from kopf.reactor import causation, daemons, effects, handling, lifecycles, registries
+from kopf.storage import finalizers, states
+from kopf.structs import (bodies, configuration, containers, diffs,
+                          handlers as handlers_, patches, resources)
+""", multi_line_output=11, line_length=88, combine_as_imports=True) == """
+from kopf.engines import loggers, posting
+from kopf.reactor import causation, daemons, effects, handling, lifecycles, registries
+from kopf.storage import finalizers, states
+from kopf.structs import bodies, configuration, containers, diffs, \\
+                         handlers as handlers_, patches, resources
+"""