Compatibility with isort 5.x

CHANGES.rst

@@ -5,6 +5,7 @@
 - Feature: Add support for ``-l``/``--line-length`` and ``-S``/``--skip-string-normalization``
 - Feature: ``--diff`` outputs a diff for each file on standard output
 - Feature: Allow to configure ``isort`` through pyproject.toml
+- Feature: Require ``isort`` >= 5.0.1 and be compatible with it.
 
 
 0.2.0 / 2020-03-11

pytest.ini

@@ -3,6 +3,7 @@ doctest_optionflags = NORMALIZE_WHITESPACE
 show_capture = no
 addopts =
   --black
-  --isort
+  ## Disable pytest-isort until it is fixed to work with isort 5.x
+  #  --isort
   --mypy
   --doctest-modules

setup.cfg

@@ -36,9 +36,10 @@ console_scripts =
 
 [options.extras_require]
 isort =
-    isort<5
+    isort>=5.0.1
 test =
     pytest
     pytest-black
-    pytest-isort
+    ## Disable pytest-isort until it is fixed to work with isort 5.x
+    #pytest-isort
     pytest-mypy

src/darker/__main__.py

@@ -15,7 +15,7 @@
     opcodes_to_edit_linenums,
 )
 from darker.git import git_diff_name_only, git_get_unmodified_content
-from darker.import_sorting import SortImports, apply_isort
+from darker.import_sorting import sort_code_string, apply_isort
 from darker.utils import get_common_root, joinlines
 from darker.verification import NotEquivalentError, verify_ast_unchanged
 from darker.version import __version__
@@ -174,7 +174,7 @@ def main(argv: List[str] = None) -> None:
     if args.version:
         print(__version__)
 
-    if args.isort and not SortImports:
+    if args.isort and not sort_code_string:
         logger.error(f"{ISORT_INSTRUCTION} to use the `--isort` option.")
         exit(1)
 

src/darker/import_sorting.py

@@ -1,14 +1,14 @@
 import logging
 from pathlib import Path
-from typing import Dict, List, Optional, Tuple, Union, cast
+from typing import Dict, List, Optional, Tuple, Union
 
 from black import find_project_root
 
 try:
-    from isort import SortImports
+    from isort.api import sort_code_string
     import isort.settings as isort_settings
 except ImportError:
-    SortImports = None
+    sort_code_string = None
     isort_settings = None
 
 logger = logging.getLogger(__name__)
@@ -19,13 +19,14 @@
 def get_isort_settings(src: Optional[Path], config: Optional[str]) -> IsortSettings:
     if src and config is None:
         project_root = find_project_root((str(src),))
-        settings: IsortSettings = isort_settings.from_path(str(project_root))
+        settings: IsortSettings
+        _, settings = isort_settings._find_config(str(project_root))
         return settings
 
-    computed_settings: IsortSettings = isort_settings.default.copy()
+    computed_settings: IsortSettings = {}
     if config:
-        isort_settings._update_with_config_file(
-            config, ('tool.isort',), computed_settings
+        computed_settings.update(
+            isort_settings._get_config_data(config, ('tool.isort',))
         )
     return computed_settings
 
@@ -41,9 +42,9 @@ def apply_isort(
         isort_settings["line_length"] = line_length
 
     logger.debug(
-        "SortImports(file_contents=..., check=True, {})".format(
+        "sort_code_string(file_contents=..., check=True, {})".format(
             ", ".join(f"{k}={v}" for k, v in isort_settings.items())
         )
     )
-    result = SortImports(file_contents=content, check=True, **isort_settings)
-    return cast(str, result.output)
+    output: str = sort_code_string(content, **isort_settings)
+    return output

src/darker/tests/test_main.py

@@ -11,7 +11,9 @@
 
 def test_isort_option_without_isort(tmpdir, without_isort, caplog):
     check_call(["git", "init"], cwd=tmpdir)
-    with patch.object(darker.__main__, "SortImports", None), pytest.raises(SystemExit):
+    with patch.object(darker.__main__, "sort_code_string", None), pytest.raises(
+        SystemExit
+    ):
 
         darker.__main__.main(["--isort", str(tmpdir)])
 
@@ -28,10 +30,10 @@ def run_isort(git_repo, monkeypatch, caplog):
     paths['test1.py'].write('changed')
     with patch.multiple(
         darker.__main__, run_black=Mock(return_value=[]), verify_ast_unchanged=Mock(),
-    ), patch("darker.import_sorting.SortImports"):
+    ), patch("darker.import_sorting.sort_code_string"):
         darker.__main__.main(["--isort", "./test1.py"])
         return SimpleNamespace(
-            SortImports=darker.import_sorting.SortImports, caplog=caplog
+            sort_code_string=darker.import_sorting.sort_code_string, caplog=caplog
         )
 
 
@@ -40,19 +42,14 @@ def test_isort_option_with_isort(run_isort):
 
 
 def test_isort_option_with_isort_calls_sortimports(run_isort):
-    run_isort.SortImports.assert_called_once_with(
-        file_contents="changed",
-        check=True,
-        **darker.import_sorting.isort_settings.default
-    )
+    run_isort.sort_code_string.assert_called_once()
+    assert run_isort.sort_code_string.call_args[0] == ("changed",)
 
 
 def test_isort_option_with_config(isort_config, run_isort):
-    isort_args = darker.import_sorting.isort_settings.default.copy()
-    isort_args["line_length"] = 120
-    run_isort.SortImports.assert_called_once_with(
-        file_contents="changed", check=True, **isort_args
-    )
+    run_isort.sort_code_string.assert_called_once()
+    assert run_isort.sort_code_string.call_args[0] == ("changed",)
+    assert run_isort.sort_code_string.call_args[1]["line_length"] == 120
 
 
 def test_format_edited_parts_empty():
@@ -110,13 +107,7 @@ def test_format_edited_parts_empty():
     'isort, black_args, print_diff, expect_stdout, expect_a_py',
     [
         (False, {}, True, A_PY_DIFF_BLACK, A_PY),
-        (
-            True,
-            {},
-            False,
-            ['ERROR:  Imports are incorrectly sorted.', ''],
-            A_PY_BLACK_ISORT,
-        ),
+        (True, {}, False, [''], A_PY_BLACK_ISORT,),
         (
             False,
             {'skip_string_normalization': True},
@@ -125,13 +116,7 @@ def test_format_edited_parts_empty():
             A_PY,
         ),
         (False, {}, False, [''], A_PY_BLACK),
-        (
-            True,
-            {},
-            True,
-            ['ERROR:  Imports are incorrectly sorted.'] + A_PY_DIFF_BLACK_ISORT,
-            A_PY,
-        ),
+        (True, {}, True, A_PY_DIFF_BLACK_ISORT, A_PY,),
     ],
 )
 def test_format_edited_parts(