Add --required-version

docs/configuration/options.md

@@ -1651,6 +1651,19 @@ Displays the currently installed version of isort.
 
 `isort --version`
 
+## Required Version
+
+Require a specific version of isort to be running. This is useful for ensuring that all contributors to your project are using the same version, because different versions of isort may format code a little differently. This option can be set in a configuration file for consistent results across environments.
+
+**Type:** String
+**Default:** ` `
+**Config default:** ` `
+**Python & Config File Name:** required_version
+**CLI Flags:**
+
+- --rv
+- --required-version
+
 ## Version Number
 
 Returns just the current version number without the logo

isort/main.py

@@ -1,4 +1,5 @@
 """Tool for sorting imports alphabetically, and automatically separated into sections."""
+
 import argparse
 import functools
 import json
@@ -164,6 +165,18 @@ def _build_arg_parser() -> argparse.ArgumentParser:
         dest="show_version",
         help="Displays the currently installed version of isort.",
     )
+    general_group.add_argument(
+        "--rv",
+        "--required-version",
+        default="",
+        dest="required_version",
+        type=str,
+        help="Require a specific version of isort to be running. This is useful for"
+        " ensuring that all contributors to your project are using the same"
+        " version, because different versions of isort may format code a little"
+        " differently. This option can be set in a configuration file for consistent"
+        " results across environments.",
+    )
     general_group.add_argument(
         "--vn",
         "--version-number",
@@ -1124,6 +1137,17 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
     if show_config:
         print(json.dumps(config.__dict__, indent=4, separators=(",", ": "), default=_preconvert))
         return
+
+    if (
+        config.required_version
+        and config.required_version != __version__
+        and config.required_version != __version__.split(".")[0]
+    ):
+        sys.exit(
+            f"Error: the required version `{config.required_version}` does not match the running"
+            f" version `{__version__}`!"
+        )
+
     if file_names == ["-"]:
         file_path = Path(stream_filename) if stream_filename else None
         if show_files:

isort/settings.py

@@ -145,6 +145,7 @@ class _Config:
     """
 
     py_version: str = "3"
+    required_version: str = ""
     force_to_top: FrozenSet[str] = frozenset()
     skip: FrozenSet[str] = DEFAULT_SKIP
     extend_skip: FrozenSet[str] = frozenset()
@@ -553,8 +554,8 @@ def is_supported_filetype(self, file_name: str) -> bool:
                 line = fp.readline(100)
         except OSError:
             return False
-        else:
-            return bool(_SHEBANG_RE.match(line))
+
+        return bool(_SHEBANG_RE.match(line))
 
     def _check_folder_git_ls_files(self, folder: str) -> Optional[Path]:
         env = {**os.environ, "LANG": "C.UTF-8"}

tests/unit/test_main.py

@@ -103,6 +103,46 @@ def test_ascii_art(capsys):
     assert error == ""
 
 
+def test_required_version_matches_version(capsys, tmpdir):
+    python_file = tmpdir.join("file.py")
+    python_file.write("import os")
+
+    main.main(["--required-version", __version__, str(python_file)])
+    out, error = capsys.readouterr()
+    assert out == ""
+    assert error == ""
+
+
+def test_required_version_matches_partial_version(capsys, tmpdir):
+    python_file = tmpdir.join("file.py")
+    python_file.write("import os")
+
+    main.main(["--required-version", __version__.split(".")[0], str(python_file)])
+    out, error = capsys.readouterr()
+    assert out == ""
+    assert error == ""
+
+
+def test_required_version_does_not_match_on_minor_version(tmpdir):
+    python_file = tmpdir.join("file.py")
+    python_file.write("import os")
+
+    required_version = __version__.split(".")[0] + ".999"
+    error_msg = f"Error: the required version `{required_version}` does not match the running version `{__version__}`!"
+    with pytest.raises(SystemExit, match=error_msg):
+        main.main(["--required-version", required_version, str(python_file)])
+
+
+def test_required_version_does_not_match_version(tmpdir):
+    python_file = tmpdir.join("file.py")
+    python_file.write("import os")
+
+    required_version = "0.13.2b"
+    error_msg = f"Error: the required version `{required_version}` does not match the running version `{__version__}`!"
+    with pytest.raises(SystemExit, match=error_msg):
+        main.main(["--required-version", required_version, str(python_file)])
+
+
 def test_preconvert():
     assert main._preconvert(frozenset([1, 1, 2])) == [1, 2]
     assert main._preconvert(WrapModes.GRID) == "GRID"