add format-errors and format-success options

docs/configuration/options.md

@@ -1312,6 +1312,34 @@ Tells isort to format the given files according to an extensions formatting rule
 
 - --ext-format
 
+## Format Errors
+
+Define the format used to print errors.
+
+**NOTE** Variables are `error` and `message`.
+The `error` variable prints `ERROR` with color depending on the --color option.
+
+**Type:** String  
+**Default:** `{error}: {message}`  
+**Python & Config File Name:** format_errors
+**CLI Flags:**
+
+- --format-errors
+
+## Format Success
+
+Define the format used to print successes.
+
+**NOTE** Variables are `success` and `message`.
+The `success` variable prints `SUCCESS` with color depending on the --color option.
+
+**Type:** String  
+**Default:** `{success}: {message}`  
+**Python & Config File Name:** format_success
+**CLI Flags:**
+
+- --format-success
+
 ## Deprecated Flags
 
 ==SUPPRESS==

isort/api.py

@@ -242,7 +242,9 @@ def check_stream(
         file_path=file_path,
         disregard_skip=disregard_skip,
     )
-    printer = create_terminal_printer(color=config.color_output)
+    printer = create_terminal_printer(
+        color=config.color_output, error=config.format_error, success=config.format_success
+    )
     if not changed:
         if config.verbose and not config.only_modified:
             printer.success(f"{file_path or ''} Everything Looks Good!")

isort/format.py

@@ -95,22 +95,24 @@ class BasicPrinter:
     ERROR = "ERROR"
     SUCCESS = "SUCCESS"
 
-    def __init__(self, output: Optional[TextIO] = None):
+    def __init__(self, error: str, success: str, output: Optional[TextIO] = None):
         self.output = output or sys.stdout
+        self.success_message = success
+        self.error_message = error
 
     def success(self, message: str) -> None:
-        print(f"{self.SUCCESS}: {message}", file=self.output)
+        print(self.success_message.format(success=self.SUCCESS, message=message), file=self.output)
 
     def error(self, message: str) -> None:
-        print(f"{self.ERROR}: {message}", file=sys.stderr)
+        print(self.error_message.format(error=self.ERROR, message=message), file=sys.stderr)
 
     def diff_line(self, line: str) -> None:
         self.output.write(line)
 
 
 class ColoramaPrinter(BasicPrinter):
-    def __init__(self, output: Optional[TextIO] = None):
-        super().__init__(output=output)
+    def __init__(self, error: str, success: str, output: Optional[TextIO]):
+        super().__init__(error, success, output=output)
 
         # Note: this constants are instance variables instead ofs class variables
         # because they refer to colorama which might not be installed.
@@ -134,7 +136,9 @@ def diff_line(self, line: str) -> None:
         self.output.write(self.style_text(line, style))
 
 
-def create_terminal_printer(color: bool, output: Optional[TextIO] = None):
+def create_terminal_printer(
+    color: bool, output: Optional[TextIO] = None, error: str = "", success: str = ""
+):
     if color and colorama_unavailable:
         no_colorama_message = (
             "\n"
@@ -147,4 +151,6 @@ def create_terminal_printer(color: bool, output: Optional[TextIO] = None):
         print(no_colorama_message, file=sys.stderr)
         sys.exit(1)
 
-    return ColoramaPrinter(output) if color else BasicPrinter(output)
+    return (
+        ColoramaPrinter(error, success, output) if color else BasicPrinter(error, success, output)
+    )

isort/main.py

@@ -127,7 +127,9 @@ def _print_hard_fail(
         "This should NEVER happen.\n"
         "If encountered, please open an issue: https://github.com/PyCQA/isort/issues/new"
     )
-    printer = create_terminal_printer(color=config.color_output)
+    printer = create_terminal_printer(
+        color=config.color_output, error=config.format_error, success=config.format_success
+    )
     printer.error(message)
 
 
@@ -297,6 +299,16 @@ def _build_arg_parser() -> argparse.ArgumentParser:
         action="store_true",
         help="Tells isort to apply changes interactively.",
     )
+    general_group.add_argument(
+        "--format-error",
+        dest="format_error",
+        help="Override the format used to print errors.",
+    )
+    general_group.add_argument(
+        "--format-success",
+        dest="format_success",
+        help="Override the format used to print success.",
+    )
 
     target_group.add_argument(
         "files", nargs="*", help="One or more Python source files that need their imports sorted."
@@ -1094,13 +1106,17 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
                 raise_on_skip=False,
             )
     elif "/" in file_names and not allow_root:
-        printer = create_terminal_printer(color=config.color_output)
+        printer = create_terminal_printer(
+            color=config.color_output, error=config.format_error, success=config.format_success
+        )
         printer.error("it is dangerous to operate recursively on '/'")
         printer.error("use --allow-root to override this failsafe")
         sys.exit(1)
     else:
         if stream_filename:
-            printer = create_terminal_printer(color=config.color_output)
+            printer = create_terminal_printer(
+                color=config.color_output, error=config.format_error, success=config.format_success
+            )
             printer.error("Filename override is intended only for stream (-) sorting.")
             sys.exit(1)
         skipped: List[str] = []
@@ -1222,7 +1238,9 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
         sys.exit(1)
 
     if no_valid_encodings:
-        printer = create_terminal_printer(color=config.color_output)
+        printer = create_terminal_printer(
+            color=config.color_output, error=config.format_error, success=config.format_success
+        )
         printer.error("No valid encodings.")
         sys.exit(1)
 

isort/settings.py

@@ -217,6 +217,8 @@ class _Config:
     star_first: bool = False
     import_dependencies = Dict[str, str]
     git_ignore: Dict[Path, Set[Path]] = field(default_factory=dict)
+    format_error: str = "{error}: {message}"
+    format_success: str = "{success}: {message}"
 
     def __post_init__(self):
         py_version = self.py_version

tests/unit/test_format.py

@@ -21,14 +21,26 @@ def test_ask_whether_to_apply_changes_to_file():
 
 
 def test_basic_printer(capsys):
-    printer = isort.format.create_terminal_printer(color=False)
+    printer = isort.format.create_terminal_printer(
+        color=False, success="{success}: {message}", error="{error}: {message}"
+    )
     printer.success("All good!")
     out, _ = capsys.readouterr()
     assert out == "SUCCESS: All good!\n"
     printer.error("Some error")
     _, err = capsys.readouterr()
     assert err == "ERROR: Some error\n"
 
+    printer = isort.format.create_terminal_printer(
+        color=False, success="success: {message}: {success}", error="error: {message}: {error}"
+    )
+    printer.success("All good!")
+    out, _ = capsys.readouterr()
+    assert out == "success: All good!: SUCCESS\n"
+    printer.error("Some error")
+    _, err = capsys.readouterr()
+    assert err == "error: Some error: ERROR\n"
+
 
 def test_basic_printer_diff(capsys):
     printer = isort.format.create_terminal_printer(color=False)
@@ -40,7 +52,7 @@ def test_basic_printer_diff(capsys):
 
 
 def test_colored_printer_success(capsys):
-    printer = isort.format.create_terminal_printer(color=True)
+    printer = isort.format.create_terminal_printer(color=True, success="{success}: {message}")
     printer.success("All good!")
     out, _ = capsys.readouterr()
     assert "SUCCESS" in out
@@ -49,7 +61,7 @@ def test_colored_printer_success(capsys):
 
 
 def test_colored_printer_error(capsys):
-    printer = isort.format.create_terminal_printer(color=True)
+    printer = isort.format.create_terminal_printer(color=True, error="{error}: {message}")
     printer.error("Some error")
     _, err = capsys.readouterr()
     assert "ERROR" in err