Fix re-export sorter

docs/configuration/options.md

@@ -231,6 +231,19 @@ Forces line endings to the specified value. If not set, values will be guessed p
 - --le
 - --line-ending
 
+## Sort Re-exports
+
+Specifies whether to sort re-exports (`__all__` collections) automatically.
+
+**Type:** Bool  
+**Default:** `False`  
+**Config default:** `false`  
+**Python & Config File Name:** sort_reexports  
+**CLI Flags:**
+
+- --srx
+- --sort-reexports
+
 ## Sections
 
 What sections isort should display imports for and in what order

isort/core.py

@@ -24,11 +24,7 @@
     "# isort: unique-tuple",
     "# isort: assignments",
 )
-LITERAL_TYPE_MAPPING = {
-    "(": "tuple",
-    "[": "list",
-    "{": "dict",
-}
+LITERAL_TYPE_MAPPING = {"(": "tuple", "[": "list", "{": "set"}
 
 
 def process(
@@ -78,8 +74,8 @@ def process(
     end_of_file: bool = False
     verbose_output: List[str] = []
     lines_before: List[str] = []
-    auto_reexporting: bool = False
-    line_index: int = 0
+    is_reexport: bool = False
+    sort_section_pointer: int = 0
 
     if config.float_to_top:
         new_input = ""
@@ -137,6 +133,8 @@ def process(
                 line_separator = "\n"
 
             if code_sorting and code_sorting_section:
+                if is_reexport:
+                    output_stream.seek(sort_section_pointer, 0)
                 sorted_code = textwrap.indent(
                     isort.literal.assignment(
                         code_sorting_section,
@@ -152,7 +150,7 @@ def process(
                     line_separator=line_separator,
                     ignore_whitespace=config.ignore_whitespace,
                 )
-                line_index += output_stream.write(sorted_code)
+                sort_section_pointer += output_stream.write(sorted_code)
         else:
             stripped_line = line.strip()
             if stripped_line and not line_separator:
@@ -233,12 +231,13 @@ def process(
                     code_sorting_indent = line[: -len(line.lstrip())]
                     not_imports = True
                 elif config.sort_reexports and stripped_line.startswith("__all__"):
-                    code_sorting = LITERAL_TYPE_MAPPING[stripped_line.split(" = ")[1][0]]
+                    _, rhs = stripped_line.split("=")
+                    code_sorting = LITERAL_TYPE_MAPPING.get(rhs.lstrip()[0], "tuple")
                     code_sorting_indent = line[: -len(line.lstrip())]
                     not_imports = True
                     code_sorting_section += line
-                    auto_reexporting = True
-                    line_index -= len(line) - 1
+                    is_reexport = True
+                    sort_section_pointer -= len(line)
                 elif code_sorting:
                     if not stripped_line:
                         sorted_code = textwrap.indent(
@@ -256,14 +255,14 @@ def process(
                             line_separator=line_separator,
                             ignore_whitespace=config.ignore_whitespace,
                         )
-                        if auto_reexporting:
-                            output_stream.seek(line_index, 0)
-                        line_index += output_stream.write(sorted_code)
+                        if is_reexport:
+                            output_stream.seek(sort_section_pointer, 0)
+                        sort_section_pointer += output_stream.write(sorted_code)
                         not_imports = True
                         code_sorting = False
                         code_sorting_section = ""
                         code_sorting_indent = ""
-                        auto_reexporting = False
+                        is_reexport = False
                     else:
                         code_sorting_section += line
                         line = ""
@@ -357,7 +356,7 @@ def process(
                 else:
                     not_imports = True
 
-        line_index += len(line)
+        sort_section_pointer += len(line)
 
         if not_imports:
 

isort/literal.py

@@ -47,8 +47,9 @@ def assignment(code: str, sort_type: str, extension: str, config: Config = DEFAU
             f"Defined sort types are {', '.join(type_mapping.keys())}."
         )
 
-    variable_name, literal = code.split(" = ")
-    variable_name = variable_name.lstrip()
+    variable_name, literal = code.split("=")
+    variable_name = variable_name.strip()
+    literal = literal.lstrip()
     try:
         value = ast.literal_eval(literal)
     except Exception as error:

isort/main.py

@@ -323,6 +323,7 @@ def _build_arg_parser() -> argparse.ArgumentParser:
         help="Override the format used to print success.",
     )
     general_group.add_argument(
+        "--srx",
         "--sort-reexports",
         dest="sort_reexports",
         action="store_true",

tests/unit/test_isort.py

@@ -5591,3 +5591,84 @@ def test_infinite_loop_in_unmatched_parenthesis() -> None:
 
     # ensure other cases are handled correctly
     assert isort.code(test_input) == "from os import path, walk\n"
+
+
+def test_reexport() -> None:
+    test_input = """__all__ = ('foo', 'bar')
+"""
+    expd_output = """__all__ = ('bar', 'foo')
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output
+
+
+def test_reexport_leave_alone_if_not_enabled() -> None:
+    test_input = """__all__ = ('foo', 'bar')
+"""
+    assert isort.code(test_input) == test_input
+
+
+def test_reexport_multiline() -> None:
+    test_input = """__all__ = (
+    'foo',
+    'bar',
+)
+"""
+    expd_output = """__all__ = ('bar', 'foo')
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output
+
+
+def test_reexport_list() -> None:
+    test_input = """__all__ = ['foo', 'bar']
+"""
+    expd_output = """__all__ = ['bar', 'foo']
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output
+
+
+def test_reexport_set() -> None:
+    test_input = """__all__ = {'foo', 'bar'}
+"""
+    expd_output = """__all__ = {'bar', 'foo'}
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output
+
+
+def test_reexport_bare() -> None:
+    test_input = """__all__ = 'foo', 'bar'
+"""
+    expd_output = """__all__ = ('bar', 'foo')
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output
+
+
+def test_reexport_no_spaces() -> None:
+    test_input = """__all__=('foo', 'bar')
+"""
+    expd_output = """__all__ = ('bar', 'foo')
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output
+
+
+def test_reexport_not_first_line() -> None:
+    test_input = """import random
+
+    __all__ = ('foo', 'bar')
+"""
+    expd_output = """import random
+
+    __all__ = ('bar', 'foo')
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output
+
+
+def test_reexport_not_last_line() -> None:
+    test_input = """__all__ = ('foo', 'bar')
+
+    meme = "rickroll"
+"""
+    expd_output = """__all__ = ('bar', 'foo')
+
+    meme = "rickroll"
+"""
+    assert isort.code(test_input, config=Config(sort_reexports=True)) == expd_output