Implemented #1596: Provide ways for extension formatting and file paths to be specified when using streaming input from CLI.

3 files changed, 86 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a94901a0..524f4ea5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@ Changelog
 NOTE: isort follows the [semver](https://semver.org/) versioning standard.
 Find out more about isort's release policy [here](https://pycqa.github.io/isort/docs/major_releases/release_policy/).
 
+### 5.7.0 TBD
+  - Implemented #1596: Provide ways for extension formatting and file paths to be specified when using streaming input from CLI.
+
 ### 5.6.4 October 12, 2020
   - Fixed #1556: Empty line added between imports that should be skipped.
 
diff --git a/isort/main.py b/isort/main.py
index 5dd661f4..8e7d0e01 100644
--- a/isort/main.py
+++ b/isort/main.py
@@ -383,6 +383,11 @@ def _build_arg_parser() -> argparse.ArgumentParser:
         action="store_true",
         help="Tells isort not to follow symlinks that are encountered when running recursively.",
     )
+    target_group.add_argument(
+        "--filename",
+        dest="filename",
+        help="Provide the filename associated with a stream.",
+    )
 
     output_group.add_argument(
         "-a",
@@ -653,6 +658,11 @@ def _build_arg_parser() -> argparse.ArgumentParser:
         action="store_true",
         help="Tells isort to use color in terminal output.",
     )
+    output_group.add_argument(
+        "--ext-format",
+        dest="ext_format",
+        help="Tells isort to format the given files according to an extensions formatting rules.",
+    )
 
     section_group.add_argument(
         "--sd",
@@ -938,6 +948,8 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
     write_to_stdout = config_dict.pop("write_to_stdout", False)
     deprecated_flags = config_dict.pop("deprecated_flags", False)
     remapped_deprecated_args = config_dict.pop("remapped_deprecated_args", False)
+    stream_filename = config_dict.pop("filename", None)
+    ext_format = config_dict.pop("ext_format", None)
     wrong_sorted_files = False
     all_attempt_broken = False
     no_valid_encodings = False
@@ -952,6 +964,7 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
         print(json.dumps(config.__dict__, indent=4, separators=(",", ": "), default=_preconvert))
         return
     elif file_names == ["-"]:
+        file_path = Path(stream_filename) if stream_filename else None
         if show_files:
             sys.exit("Error: can't show files for streaming input.")
 
@@ -960,6 +973,8 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
                 input_stream=sys.stdin if stdin is None else stdin,
                 config=config,
                 show_diff=show_diff,
+                file_path=file_path,
+                extension=ext_format,
             )
 
             wrong_sorted_files = incorrectly_sorted
@@ -969,8 +984,14 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
                 output_stream=sys.stdout,
                 config=config,
                 show_diff=show_diff,
+                file_path=file_path,
+                extension=ext_format,
             )
     else:
+        if stream_filename:
+            printer = create_terminal_printer(color=config.color_output)
+            printer.error("Filename override is intended only for stream (-) sorting.")
+            sys.exit(1)
         skipped: List[str] = []
         broken: List[str] = []
 
@@ -1005,6 +1026,7 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
                     check=check,
                     ask_to_apply=ask_to_apply,
                     write_to_stdout=write_to_stdout,
+                    extension=ext_format,
                 ),
                 file_names,
             )
@@ -1018,6 +1040,7 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
                     ask_to_apply=ask_to_apply,
                     show_diff=show_diff,
                     write_to_stdout=write_to_stdout,
+                    extension=ext_format,
                 )
                 for file_name in file_names
             )
diff --git a/tests/unit/test_main.py b/tests/unit/test_main.py
index 70eafb3a..08f27463 100644
--- a/tests/unit/test_main.py
+++ b/tests/unit/test_main.py
@@ -348,6 +348,66 @@ def test_isort_command():
     assert main.ISortCommand
 
 
+def test_isort_filename_overrides(tmpdir, capsys):
+    """Tests isorts available approaches for overriding filename and extension based behavior"""
+    input_text = """
+import b
+import a
+
+def function():
+    pass
+"""
+
+    def build_input_content():
+        return UnseekableTextIOWrapper(BytesIO(input_text.encode("utf8")))
+
+    main.main(["-"], stdin=build_input_content())
+    out, error = capsys.readouterr()
+    assert not error
+    assert out == (
+        """
+import a
+import b
+
+
+def function():
+    pass
+"""
+    )
+
+    main.main(["-", "--ext-format", "pyi"], stdin=build_input_content())
+    out, error = capsys.readouterr()
+    assert not error
+    assert out == (
+        """
+import a
+import b
+
+def function():
+    pass
+"""
+    )
+
+    tmp_file = tmpdir.join("tmp.pyi")
+    tmp_file.write_text(input_text, encoding="utf8")
+    main.main(["-", "--filename", str(tmp_file)], stdin=build_input_content())
+    out, error = capsys.readouterr()
+    assert not error
+    assert out == (
+        """
+import a
+import b
+
+def function():
+    pass
+"""
+    )
+
+    # setting a filename override when file is passed in as non-stream is not supported.
+    with pytest.raises(SystemExit):
+        main.main([str(tmp_file), "--filename", str(tmp_file)], stdin=build_input_content())
+
+
 def test_isort_with_stdin(capsys):
     # ensures that isort sorts stdin without any flags