Merge pull request #1349 from sztamas/issue/1177/colored-output-in-ch…

…eck-mode

Adds color to ERROR and SUCCESS in check mode.

docs/configuration/options.md

@@ -937,6 +937,17 @@ See isort's determined config, as well as sources of config options.
 
 - --show-config
 
+## Color Terminal Output
+
+Tells isort to use color in terminal output.
+
+**Type:** Bool
+**Default:** `False`
+**Python & Config File Name:** color_output
+**CLI Flags:**
+
+- --color
+
 ## Deprecated Flags
 
 ==SUPPRESS==

isort/api.py

@@ -16,6 +16,7 @@
 )
 from .format import (
     ask_whether_to_apply_changes_to_file,
+    create_terminal_printer,
     format_natural,
     remove_whitespace,
     show_unified_diff,
@@ -216,13 +217,13 @@ def check_stream(
         file_path=file_path,
         disregard_skip=disregard_skip,
     )
-
+    printer = create_terminal_printer(color=config.color_output)
     if not changed:
         if config.verbose:
-            print(f"SUCCESS: {file_path or ''} Everything Looks Good!")
+            printer.success(f"{file_path or ''} Everything Looks Good!")
         return True
     else:
-        print(f"ERROR: {file_path or ''} Imports are incorrectly sorted and/or formatted.")
+        printer.error(f"{file_path or ''} Imports are incorrectly sorted and/or formatted.")
         if show_diff:
             output_stream = StringIO()
             input_stream.seek(0)

isort/format.py

@@ -4,6 +4,14 @@
 from pathlib import Path
 from typing import Optional, TextIO
 
+try:
+    import colorama
+except ImportError:
+    colorama_unavailable = True
+else:
+    colorama_unavailable = False
+    colorama.init()
+
 
 def format_simplified(import_line: str) -> str:
     import_line = import_line.strip()
@@ -70,3 +78,44 @@ def ask_whether_to_apply_changes_to_file(file_path: str) -> bool:
 def remove_whitespace(content: str, line_separator: str = "\n") -> str:
     content = content.replace(line_separator, "").replace(" ", "").replace("\x0c", "")
     return content
+
+
+class BasicPrinter:
+    ERROR = "ERROR"
+    SUCCESS = "SUCCESS"
+
+    def success(self, message: str) -> None:
+        print(f"{self.SUCCESS}: {message}")
+
+    def error(self, message: str) -> None:
+        print(
+            f"{self.ERROR}: {message}",
+            # TODO this should print to stderr, but don't want to make it backward incompatible now
+            # file=sys.stderr
+        )
+
+
+class ColoramaPrinter(BasicPrinter):
+    def __init__(self):
+        self.ERROR = self.style_text("ERROR", colorama.Fore.RED)
+        self.SUCCESS = self.style_text("SUCCESS", colorama.Fore.GREEN)
+
+    @staticmethod
+    def style_text(text: str, style: str) -> str:
+        return style + text + colorama.Style.RESET_ALL
+
+
+def create_terminal_printer(color: bool):
+    if color and colorama_unavailable:
+        no_colorama_message = (
+            "\n"
+            "Sorry, but to use --color (color_output) the colorama python package is required.\n\n"
+            "Reference: https://pypi.org/project/colorama/\n\n"
+            "You can either install it separately on your system or as the colors extra "
+            "for isort. Ex: \n\n"
+            "$ pip install isort[colors]\n"
+        )
+        print(no_colorama_message, file=sys.stderr)
+        sys.exit(1)
+
+    return ColoramaPrinter() if color else BasicPrinter()

isort/main.py

@@ -615,6 +615,12 @@ def _build_arg_parser() -> argparse.ArgumentParser:
             " aliases to signify intent and change behaviour."
         ),
     )
+    parser.add_argument(
+        "--color",
+        dest="color_output",
+        action="store_true",
+        help="Tells isort to use color in terminal output.",
+    )
     parser.add_argument(
         "--float-to-top",
         dest="float_to_top",

isort/settings.py

@@ -175,6 +175,7 @@ class _Config:
     filter_files: bool = False
     formatter: str = ""
     formatting_function: Optional[Callable[[str, str, object], str]] = None
+    color_output: bool = False
 
     def __post_init__(self):
         py_version = self.py_version

pyproject.toml

@@ -42,10 +42,12 @@ pipreqs = {version = "*", optional = true}
 requirementslib = {version = "*", optional = true}
 tomlkit = {version = ">=0.5.3", optional = true}
 pip-api = {version = "*", optional = true}
+colorama = {version = "^0.4.3", optional = true}
 
 [tool.poetry.extras]
 pipfile_deprecated_finder = ["pipreqs", "tomlkit", "requirementslib", "pip-shims<=0.3.4"]
 requirements_deprecated_finder = ["pipreqs", "pip-api"]
+colors = ["colorama"]
 
 [tool.poetry.dev-dependencies]
 vulture = "^1.0"

tests/test_format.py

@@ -1,5 +1,6 @@
 from unittest.mock import MagicMock, patch
 
+import colorama
 import pytest
 from hypothesis_auto import auto_pytest_magic
 
@@ -16,3 +17,41 @@ def test_ask_whether_to_apply_changes_to_file():
     with patch("isort.format.input", MagicMock(return_value="q")):
         with pytest.raises(SystemExit):
             assert isort.format.ask_whether_to_apply_changes_to_file("")
+
+
+def test_basic_printer(capsys):
+    printer = isort.format.create_terminal_printer(color=False)
+    printer.success("All good!")
+    out, _ = capsys.readouterr()
+    assert out == "SUCCESS: All good!\n"
+    printer.error("Some error")
+    out, _ = capsys.readouterr()
+    assert out == "ERROR: Some error\n"
+
+
+def test_colored_printer_success(capsys):
+    printer = isort.format.create_terminal_printer(color=True)
+    printer.success("All good!")
+    out, _ = capsys.readouterr()
+    assert "SUCCESS" in out
+    assert "All good!" in out
+    assert colorama.Fore.GREEN in out
+
+
+def test_colored_printer_error(capsys):
+    printer = isort.format.create_terminal_printer(color=True)
+    printer.error("Some error")
+    out, _ = capsys.readouterr()
+    assert "ERROR" in out
+    assert "Some error" in out
+    assert colorama.Fore.RED in out
+
+
+@patch("isort.format.colorama_unavailable", True)
+def test_colorama_not_available_handled_gracefully(capsys):
+    with pytest.raises(SystemExit) as system_exit:
+        _ = isort.format.create_terminal_printer(color=True)
+    assert system_exit.value.code > 0
+    _, err = capsys.readouterr()
+    assert "colorama" in err
+    assert "colors extra" in err

tests/test_isort.py

@@ -2683,7 +2683,8 @@ def test_strict_whitespace_by_default(capsys) -> None:
     test_input = "import os\nfrom django.conf import settings\n"
     assert not api.check_code_string(test_input)
     out, _ = capsys.readouterr()
-    assert out == "ERROR:  Imports are incorrectly sorted and/or formatted.\n"
+    assert "ERROR" in out
+    assert out.endswith("Imports are incorrectly sorted and/or formatted.\n")
 
 
 def test_strict_whitespace_no_closing_newline_issue_676(capsys) -> None: