diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 51340beb..da22c03c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,7 +36,7 @@ jobs:
         python-version: ${{matrix.python-version}}
 
     - run: |
-        uv run ${{matrix.extra_deps}} -m ${{ matrix.os == 'ubuntu-latest' && 'coverage run -m' || '' }} pytest -n=auto
+        uv run ${{matrix.extra_deps}} --extra black -m ${{ matrix.os == 'ubuntu-latest' && 'coverage run -m' || '' }} pytest -n=auto -vv
     - run: |
         uv run -m coverage combine
         mv .coverage .coverage.${{ matrix.python-version }}-${{matrix.os}}-${{strategy.job-index}}
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9a05e291..de72e6fe 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -27,6 +27,14 @@ repos:
   repo: https://github.com/myint/autoflake
   rev: v2.3.1
 
+- repo: local
+  hooks:
+  - id: replace-words
+    name: Replace Words
+    entry: python3 scripts/replace_words.py
+    language: system
+    files: \.(md|py)$
+
 - repo: https://github.com/asottile/setup-cfg-fmt
   rev: v2.5.0
   hooks:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7bf28927..5eb44e99 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,7 +8,7 @@
 
 ## Fixed
 
-- use '.model_fields' on pydantic model class and not instance. This fixes a deprecation warning in the upcomming pydantic v2.11 (#169)
+- use '.model_fields' on pydantic model class and not instance. This fixes a deprecation warning in the upcoming pydantic v2.11 (#169)
 
 <a id='changelog-0.18.1'></a>
 # 0.18.1 — 2024-12-22
@@ -346,7 +346,7 @@
 
 ### Fix
 
-- remove upper bound from dependencies in pyproject.toml
+- remove upper bound from dependency in pyproject.toml
 
 ## v0.5.1 (2023-10-20)
 
diff --git a/changelog.d/20250106_220025_15r10nk-git_format_cmd.md b/changelog.d/20250106_220025_15r10nk-git_format_cmd.md
new file mode 100644
index 00000000..fa816755
--- /dev/null
+++ b/changelog.d/20250106_220025_15r10nk-git_format_cmd.md
@@ -0,0 +1,7 @@
+### Added
+
+- You can now specify which tool you want to use to format your code by setting a `format-command` in your [configuration](https://15r10nk.github.io/inline-snapshot/latest/configuration/#format-command).
+
+### Changed
+
+- **BREAKING-CHANGE** you have to install `inline-snapshot[black]` now if you want to format your code like in the previous versions. This option is not required if you use a `format-command`.
diff --git a/changelog.d/20250109_071706_15r10nk-git_format_cmd.md b/changelog.d/20250109_071706_15r10nk-git_format_cmd.md
new file mode 100644
index 00000000..95548c00
--- /dev/null
+++ b/changelog.d/20250109_071706_15r10nk-git_format_cmd.md
@@ -0,0 +1,4 @@
+### Fixed
+
+- Load default config values even if `[tool.inline-snapshot]` is missing.
+  This makes the documented default shortcuts `--review` and `--fix` work.
diff --git a/docs/changelog.md b/docs/changelog.md
index 786b75d5..3e1b4202 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -1 +1,16 @@
+
+
+``` python exec="1"
+from pathlib import Path
+
+new_changes = list(Path.cwd().glob("changelog.d/*.md"))
+
+if new_changes:
+    print("# upcomming changes")
+
+for file in new_changes:
+    print(file.read_text().replace("###", "##"))
+```
+
+
 --8<-- "CHANGELOG.md"
diff --git a/docs/code_generation.md b/docs/code_generation.md
index 42ccbcfd..fd76d618 100644
--- a/docs/code_generation.md
+++ b/docs/code_generation.md
@@ -97,15 +97,25 @@ The code is generated in the following way:
             ```
 
 
-4. The code is formatted with black.
+4. The new code fragments are formatted with black if it is installed.
 
+    !!! note
+        Black is an optional dependency since inline-snapshot v0.19.0.
+        You can install it with:
+        ``` sh
+        pip install inline-snapshot[black]
+        ```
 
-5. The whole file is formatted with black if it was formatted before.
+5. The whole file is formatted
+    * with black if it was formatted with black before.
 
-    !!! note
-        The black formatting of the whole file could not work for the following reasons:
+        !!! note
+            The black formatting of the whole file could not work for the following reasons:
+
+            1. black is configured with cli arguments and not in a configuration file.<br>
+               **Solution:** configure black in a [configuration file](https://black.readthedocs.io/en/stable/usage_and_configuration/the_basics.html#configuration-via-a-file)
+            2. inline-snapshot uses a different black version.<br>
+               **Solution:** specify which black version inline-snapshot should use by adding black with a specific version to your dependencies.
+            3. black is not installed. Black is an optional dependency since inline-snapshot v0.19.0
 
-        1. black is configured with cli arguments and not in a configuration file.<br>
-           **Solution:** configure black in a [configuration file](https://black.readthedocs.io/en/stable/usage_and_configuration/the_basics.html#configuration-via-a-file)
-        2. inline-snapshot uses a different black version.<br>
-           **Solution:** specify which black version inline-snapshot should use by adding black with a specific version to your dependencies.
+    * or with the [format-command][format-command] if you defined one.
diff --git a/docs/configuration.md b/docs/configuration.md
index 851c99cc..0a88cf84 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -4,6 +4,7 @@ Default configuration:
 [tool.inline-snapshot]
 hash-length=15
 default-flags=["short-report"]
+format-command=""
 
 [tool.inline-snapshot.shortcuts]
 review=["review"]
@@ -23,3 +24,12 @@ fix=["create","fix"]
     By default, it will be `<pytest_config_dir>/.inline-snapshot`,
     where `<pytest_config_dir>` is replaced by the directory containing the Pytest configuration file, if any.
     External snapshots will be stored in the `external` subfolder of the storage directory.
+* **format-command:[](){#format-command}** allows you to specify a custom command which is used to format the python code after code is changed.
+   ``` toml
+   [tool.inline-snapshot]
+   format-command="ruff format --stdin-filename {filename}"
+   ```
+   The placeholder `{filename}` can be used to specify the filename if it is needed to find the correct formatting options for this file.
+
+    !!! important
+        The command should **not** format the file on disk. The current file content (with the new code changes) is passed to *stdin* and the formatted content should be written to *stdout*.
diff --git a/mkdocs.yml b/mkdocs.yml
index 04fe6417..87cf55d9 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -72,6 +72,7 @@ markdown_extensions:
 - pymdownx.superfences
 - pymdownx.tabbed:
     alternate_style: true
+- attr_list
 
 plugins:
 - mkdocstrings:
@@ -85,6 +86,7 @@ plugins:
 - markdown-exec:
     ansi: required
 - replace-url
+- autorefs
 
 
 extra:
diff --git a/pyproject.toml b/pyproject.toml
index 1801ebcf..45f718ca 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,12 +25,9 @@ classifiers = [
 ]
 dependencies = [
   "asttokens>=2.0.5",
-  "black>=23.3.0",
-  "click>=8.1.4",
   "executing>=2.1.0",
   "rich>=13.7.1",
-  "tomli>=2.0.0; python_version < '3.11'",
-  "typing-extensions"
+  "tomli>=2.0.0; python_version < '3.11'"
 ]
 description = "golden master/snapshot/approval testing library which puts the values right into your source code"
 keywords = []
@@ -39,6 +36,12 @@ readme = "README.md"
 requires-python = ">=3.8"
 version = "0.18.2"
 
+[project.optional-dependencies]
+black = [
+  "black>=23.3.0",
+  "click>=8.1.4"
+]
+
 [dependency-groups]
 dev = [
     "hypothesis>=6.75.5",
@@ -99,6 +102,7 @@ dependencies = [
   "mkdocs-material[imaging]>=9.5.17",
   "mike",
   "mkdocstrings[python]>=0.19.0",
+  "mkdocs-autorefs",
   "replace-url @ {root:uri}/docs/plugins",
   "pytest",
   "black"
@@ -130,6 +134,7 @@ matrix.extra-deps.dependencies = [
 
 [tool.hatch.envs.hatch-test]
 extra-dependencies = [
+  "inline-snapshot[black]",
   "dirty-equals>=0.7.0",
   "hypothesis>=6.75.5",
   "mypy>=1.2.0",
@@ -141,18 +146,20 @@ extra-dependencies = [
 env-vars.TOP = "{root}"
 
 [tool.hatch.envs.hatch-test.scripts]
-run = "pytest{env:HATCH_TEST_ARGS:} --use-uv {args}"
-run-cov = "coverage run -m pytest{env:HATCH_TEST_ARGS:} --use-uv {args}"
+run = "pytest{env:HATCH_TEST_ARGS:} {args}"
+run-cov = "coverage run -m pytest{env:HATCH_TEST_ARGS:} {args}"
 cov-combine = "coverage combine"
 cov-report=["coverage report","coverage html"]
 
 [tool.hatch.envs.types]
 extra-dependencies = [
+  "inline-snapshot[black]",
   "mypy>=1.0.0",
   "pytest",
   "hypothesis>=6.75.5",
   "pydantic",
-  "attrs"
+  "attrs",
+  "typing-extensions"
 ]
 
 [[tool.hatch.envs.types.matrix]]
diff --git a/scripts/replace_words.py b/scripts/replace_words.py
new file mode 100644
index 00000000..fa346d38
--- /dev/null
+++ b/scripts/replace_words.py
@@ -0,0 +1,24 @@
+import re
+import sys
+
+
+def replace_words(file_path, replacements):
+    with open(file_path) as file:
+        content = file.read()
+
+    for old_word, new_word in replacements.items():
+        content = re.sub(rf"\b{re.escape(old_word)}\b", new_word, content)
+
+    with open(file_path, "w") as file:
+        file.write(content)
+
+
+if __name__ == "__main__":
+
+    replacements = {
+        "http://localhost:8000/inline-snapshot/": "https://15r10nk.github.io/inline-snapshot/latest/",
+    }
+
+    for file_path in sys.argv[1:]:
+        print(file_path)
+        replace_words(file_path, replacements)
diff --git a/src/inline_snapshot/_config.py b/src/inline_snapshot/_config.py
index 99624c6d..aad23d1f 100644
--- a/src/inline_snapshot/_config.py
+++ b/src/inline_snapshot/_config.py
@@ -19,6 +19,7 @@ class Config:
     hash_length: int = 12
     default_flags: List[str] = field(default_factory=lambda: ["short-report"])
     shortcuts: Dict[str, List[str]] = field(default_factory=dict)
+    format_command: Optional[str] = None
     storage_dir: Optional[Path] = None
 
 
@@ -27,35 +28,37 @@ class Config:
 
 def read_config(path: Path) -> Config:
     result = Config()
+    config = {}
     if path.exists():
-
         data = loads(path.read_text("utf-8"))
 
         try:
             config = data["tool"]["inline-snapshot"]
         except KeyError:
             pass
-        else:
-            try:
-                result.hash_length = config["hash-length"]
-            except KeyError:
-                pass
-
-            try:
-                result.default_flags = config["default-flags"]
-            except KeyError:
-                pass
-
-            result.shortcuts = config.get(
-                "shortcuts", {"fix": ["create", "fix"], "review": ["review"]}
-            )
-
-            if storage_dir := config.get("storage-dir"):
-                storage_dir = Path(storage_dir)
-                if not storage_dir.is_absolute():
-                    # Make it relative to pyproject.toml, and absolute.
-                    storage_dir = path.parent.joinpath(storage_dir).absolute()
-                result.storage_dir = storage_dir
+
+    try:
+        result.hash_length = config["hash-length"]
+    except KeyError:
+        pass
+
+    try:
+        result.default_flags = config["default-flags"]
+    except KeyError:
+        pass
+
+    result.shortcuts = config.get(
+        "shortcuts", {"fix": ["create", "fix"], "review": ["review"]}
+    )
+
+    if storage_dir := config.get("storage-dir"):
+        storage_dir = Path(storage_dir)
+        if not storage_dir.is_absolute():
+            # Make it relative to pyproject.toml, and absolute.
+            storage_dir = path.parent.joinpath(storage_dir).absolute()
+        result.storage_dir = storage_dir
+
+    result.format_command = config.get("format-command", None)
 
     env_var = "INLINE_SNAPSHOT_DEFAULT_FLAGS"
     if env_var in os.environ:
diff --git a/src/inline_snapshot/_format.py b/src/inline_snapshot/_format.py
index a0b8aa17..b3d5b6c8 100644
--- a/src/inline_snapshot/_format.py
+++ b/src/inline_snapshot/_format.py
@@ -1,11 +1,47 @@
+import subprocess as sp
 import warnings
 
-from black import main
-from click.testing import CliRunner
-from inline_snapshot._problems import raise_problem
+from rich.markup import escape
+
+from . import _config
+from ._problems import raise_problem
+
+
+def enforce_formatting():
+    return _config.config.format_command is not None
 
 
 def format_code(text, filename):
+    if _config.config.format_command is not None:
+        format_command = _config.config.format_command.format(filename=filename)
+        result = sp.run(
+            format_command, shell=True, input=text.encode("utf-8"), capture_output=True
+        )
+        if result.returncode != 0:
+            raise_problem(
+                f"""\
+[b]The format_command '{escape(format_command)}' caused the following error:[/b]
+"""
+                + result.stdout.decode("utf-8")
+                + result.stderr.decode("utf-8")
+            )
+            return text
+        return result.stdout.decode("utf-8")
+
+    try:
+        from black import main
+        from click.testing import CliRunner
+    except ImportError:
+        raise_problem(
+            f"""\
+[b]inline-snapshot is not able to format your code.[/b]
+This issue can be solved by:
+ * installing {escape('inline-snapshot[black]')} which gives you the same formatting like in older versions
+ * adding a `format-command` to your pyproject.toml (see [link=https://15r10nk.github.io/inline-snapshot/latest/configuration/#format-command]https://15r10nk.github.io/inline-snapshot/latest/configuration/#format-command[/link] for more information).
+"""
+        )
+        return text
+
     with warnings.catch_warnings():
         warnings.simplefilter("ignore")
 
@@ -17,7 +53,7 @@ def format_code(text, filename):
     if result.exit_code != 0:
         raise_problem(
             """\
-black could not format your code, which might be caused by this issue:
+[b]black could not format your code, which might be caused by this issue:[/b]
     [link=https://github.com/15r10nk/inline-snapshot/issues/138]https://github.com/15r10nk/inline-snapshot/issues/138[/link]\
 """
         )
diff --git a/src/inline_snapshot/_problems.py b/src/inline_snapshot/_problems.py
index c8272ad8..d6a9641c 100644
--- a/src/inline_snapshot/_problems.py
+++ b/src/inline_snapshot/_problems.py
@@ -14,6 +14,7 @@ def report_problems(console: Console):
         return
     console.rule("[red]Problems")
     for problem in all_problems:
-        console.print(f"[b]{problem}")
+        console.print(f"{problem}")
+        console.print()
 
     all_problems = set()
diff --git a/src/inline_snapshot/_rewrite_code.py b/src/inline_snapshot/_rewrite_code.py
index 0cab4c56..109e4b90 100644
--- a/src/inline_snapshot/_rewrite_code.py
+++ b/src/inline_snapshot/_rewrite_code.py
@@ -13,8 +13,10 @@
 import asttokens.util
 from asttokens import LineNumbers
 
+from ._format import enforce_formatting
 from ._format import format_code
 
+
 if sys.version_info >= (3, 10):
     from itertools import pairwise
 else:
@@ -158,9 +160,11 @@ def new_code(self) -> str:
 
         code = self.filename.read_text("utf-8")
 
-        is_formatted = code == format_code(code, self.filename)
+        format_whole_file = enforce_formatting() or code == format_code(
+            code, self.filename
+        )
 
-        if not is_formatted:
+        if not format_whole_file:
             logging.info(f"file is not formatted with black: {self.filename}")
             import black
 
@@ -180,7 +184,7 @@ def new_code(self) -> str:
             ],
         )
 
-        if is_formatted:
+        if format_whole_file:
             new_code = format_code(new_code, self.filename)
 
         return new_code
diff --git a/src/inline_snapshot/_source_file.py b/src/inline_snapshot/_source_file.py
index ba8a94bc..d3f55eca 100644
--- a/src/inline_snapshot/_source_file.py
+++ b/src/inline_snapshot/_source_file.py
@@ -2,6 +2,7 @@
 from pathlib import Path
 
 from executing import Source
+from inline_snapshot._format import enforce_formatting
 from inline_snapshot._format import format_code
 from inline_snapshot._utils import normalize
 from inline_snapshot._utils import simple_token
@@ -24,7 +25,7 @@ def filename(self):
         return self._source.filename
 
     def _format(self, text):
-        if self._source is None:
+        if self._source is None or enforce_formatting():
             return text
         else:
             return format_code(text, Path(self._source.filename))
diff --git a/src/inline_snapshot/_types.py b/src/inline_snapshot/_types.py
index d6501894..50807a76 100644
--- a/src/inline_snapshot/_types.py
+++ b/src/inline_snapshot/_types.py
@@ -7,10 +7,10 @@
 from typing import TYPE_CHECKING
 from typing import TypeVar
 
-from typing_extensions import TypeAlias
-
 if TYPE_CHECKING:
 
+    from typing_extensions import TypeAlias
+
     T = TypeVar("T")
 
     Snapshot: TypeAlias = T
diff --git a/src/inline_snapshot/_unmanaged.py b/src/inline_snapshot/_unmanaged.py
index 5e46b9b5..111d86aa 100644
--- a/src/inline_snapshot/_unmanaged.py
+++ b/src/inline_snapshot/_unmanaged.py
@@ -17,13 +17,23 @@ def is_dirty_equal(value):
 
 
 def update_allowed(value):
-    return not (is_dirty_equal(value) or isinstance(value, (Is, Snapshot)))  # type: ignore
+    global unmanaged_types
+    return not (is_dirty_equal(value) or isinstance(value, tuple(unmanaged_types)))  # type: ignore
+
+
+unmanaged_types = [Is, Snapshot]
 
 
 def is_unmanaged(value):
     return not update_allowed(value)
 
 
+def declare_unmanaged(typ):
+    global unmanaged_types
+    unmanaged_types.append(typ)
+    return typ
+
+
 class Unmanaged:
     def __init__(self, value):
         self.value = value
diff --git a/src/inline_snapshot/pytest_plugin.py b/src/inline_snapshot/pytest_plugin.py
index 0c540b4e..afda98ab 100644
--- a/src/inline_snapshot/pytest_plugin.py
+++ b/src/inline_snapshot/pytest_plugin.py
@@ -46,7 +46,7 @@ def pytest_addoption(parser, pluginmanager):
 
     config_path = Path("pyproject.toml")
     if config_path.exists():
-        config = _config.read_config(Path("pyproject.toml"))
+        config = _config.read_config(config_path)
         for name, value in config.shortcuts.items():
             value = ",".join(value)
             group.addoption(
diff --git a/src/inline_snapshot/testing/_example.py b/src/inline_snapshot/testing/_example.py
index 62f0e82f..3badf584 100644
--- a/src/inline_snapshot/testing/_example.py
+++ b/src/inline_snapshot/testing/_example.py
@@ -78,6 +78,16 @@ def snapshot_env():
 )
 
 
+def normalize(text):
+    text = ansi_escape.sub("", text)
+
+    # fix windows problems
+    text = text.replace("\u2500", "-")
+    text = text.replace("\r", "")
+    text = text.replace(" \n", " ⏎\n")
+    return text
+
+
 class Example:
     def __init__(self, files: str | dict[str, str]):
         """
@@ -228,7 +238,7 @@ def run_inline(
                 assert changed_files == current_files
 
             if report is not None:
-                assert report == report_output.getvalue()
+                assert report == normalize(report_output.getvalue())
 
             return Example(self._read_files(tmp_path))
 
@@ -236,6 +246,7 @@ def run_pytest(
         self,
         args: list[str] = [],
         *,
+        term_columns=80,
         env: dict[str, str] = {},
         changed_files: Snapshot[dict[str, str]] | None = None,
         report: Snapshot[str] | None = None,
@@ -265,8 +276,6 @@ def run_pytest(
 
             cmd = [sys.executable, "-m", "pytest", *args]
 
-            term_columns = 80
-
             command_env = dict(os.environ)
             command_env["TERM"] = "unknown"
             command_env["COLUMNS"] = str(
@@ -307,14 +316,7 @@ def run_pytest(
 
                 report_str = "\n".join(report_list)
 
-                report_str = ansi_escape.sub("", report_str)
-
-                # fix windows problems
-                report_str = report_str.replace("\u2500", "-")
-                report_str = report_str.replace("\r", "")
-                report_str = report_str.replace(" \n", " ⏎\n")
-
-                assert report_str == report, repr(report_str)
+                assert normalize(report_str) == report, repr(report_str)
 
             if changed_files is not None:
                 current_files = {}
diff --git a/tests/_is_normalized.py b/tests/_is_normalized.py
new file mode 100644
index 00000000..fa8bd8d4
--- /dev/null
+++ b/tests/_is_normalized.py
@@ -0,0 +1,23 @@
+from inline_snapshot._unmanaged import declare_unmanaged
+
+
+@declare_unmanaged
+class IsNormalized:
+    def __init__(self, func, value) -> None:
+        self._func = func
+        self._value = value
+        self._last_value = None
+
+    def __eq__(self, other) -> bool:
+        self._last_value = self._func(other)
+        return self._last_value == self._value
+
+    def __repr__(self):
+        return f"IsNormalized({self._value}, should_be={self._last_value!r})"
+
+
+def normalization(func):
+    def f(value):
+        return IsNormalized(func, value)
+
+    return f
diff --git a/tests/conftest.py b/tests/conftest.py
index 2159aa85..08993d16 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -43,15 +43,6 @@ def check_pypy(request):
     yield
 
 
-def pytest_addoption(parser):
-    parser.addoption(
-        "--use-uv",
-        action="store_true",
-        default=False,
-        help="install different package versions at test time",
-    )
-
-
 @pytest.fixture()
 def check_update(source):
     def w(source_code, *, flags="", reported_flags=None, number=1):
diff --git a/tests/test_config.py b/tests/test_config.py
index 98fcb518..8e11ccf8 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -54,3 +54,27 @@ def test_shortcuts():
             """,
         }
     ).run_pytest(["--strim"], changed_files=trimmed_files)
+
+
+def test_default_shortcuts():
+
+    Example(
+        {
+            **file_to_trim,
+            "pyproject.toml": """
+            """,
+        }
+    ).run_pytest(
+        ["--fix"],
+        changed_files=snapshot(
+            {
+                "test_a.py": """\
+from inline_snapshot import snapshot
+
+def test_a():
+    assert 1 <= snapshot(5)
+    assert 1 == snapshot(1)
+"""
+            }
+        ),
+    )
diff --git a/tests/test_formating.py b/tests/test_formating.py
index c8f4c6d6..9b347a7c 100644
--- a/tests/test_formating.py
+++ b/tests/test_formating.py
@@ -1,9 +1,13 @@
+import re
+import sys
 from types import SimpleNamespace
 
 from click.testing import CliRunner
 from inline_snapshot import snapshot
 from inline_snapshot.testing import Example
 
+from tests._is_normalized import normalization
+
 
 def test_black_formatting_error(mocker):
     mocker.patch.object(CliRunner, "invoke", return_value=SimpleNamespace(exit_code=1))
@@ -33,9 +37,10 @@ def test_something():
         ),
         report=snapshot(
             """\
-─────────────────────────────────── Problems ───────────────────────────────────
+----------------------------------- Problems -----------------------------------
 black could not format your code, which might be caused by this issue:
     https://github.com/15r10nk/inline-snapshot/issues/138
+
 """
         ),
     )
@@ -57,3 +62,152 @@ def test_a():
     return None
     """
     ).run_pytest(returncode=0)
+
+
+def test_format_command():
+    Example(
+        {
+            "fmt_cmd.py": """\
+from sys import stdin
+import re
+
+text=stdin.read()
+text=re.sub("#.*","",text)
+print(text)
+""",
+            "pyproject.toml": f"""\
+[tool.inline-snapshot]
+format-command="{sys.executable} fmt_cmd.py {{filename}}"
+""",
+            "test_a.py": """\
+from inline_snapshot import snapshot
+# some comment
+def test_a():
+    assert "5" == snapshot('''3''')# abc
+""",
+        }
+    ).run_pytest(
+        ["--inline-snapshot=fix"],
+        changed_files=snapshot(
+            {
+                "test_a.py": """\
+from inline_snapshot import snapshot
+
+def test_a():
+    assert "5" == snapshot('5')
+
+"""
+            }
+        ),
+    )
+
+
+def test_format_command_fail():
+
+    @normalization
+    def NoPaths(text):
+        text = re.sub(
+            "The format_command.*following error:",
+            lambda m: m[0].replace("\n", ""),
+            text,
+            flags=re.MULTILINE | re.DOTALL,
+        )
+        text = re.sub("/[^ ]*/", "/.../", text, flags=re.MULTILINE)
+        return text
+
+    Example(
+        {
+            "fmt_cmd.py": """
+import sys
+print("some problem")
+sys.exit(1)
+""",
+            "pyproject.toml": f"""\
+[tool.inline-snapshot]
+format-command="{sys.executable} fmt_cmd.py {{filename}}"
+""",
+            "test_a.py": """
+from inline_snapshot import snapshot
+
+def test_a():
+    assert "5" ==            snapshot('''3''')
+""",
+        }
+    ).run_pytest(
+        ["--inline-snapshot=fix"],
+        term_columns=200,
+        changed_files=snapshot(
+            {
+                "test_a.py": """\
+
+from inline_snapshot import snapshot
+
+def test_a():
+    assert "5" ==            snapshot('5')
+"""
+            }
+        ),
+        report=NoPaths(
+            snapshot(
+                """\
+-------------------------------------------------------------------------------------------- Fix snapshots ---------------------------------------------------------------------------------------------
++--------------------------------------------------------------------------------------------- test_a.py ----------------------------------------------------------------------------------------------+
+| @@ -2,4 +2,4 @@                                                                                                                                                                                      |
+|                                                                                                                                                                                                      |
+|  from inline_snapshot import snapshot                                                                                                                                                                |
+|                                                                                                                                                                                                      |
+|  def test_a():                                                                                                                                                                                       |
+| -    assert "5" ==            snapshot('''3''')                                                                                                                                                      |
+| +    assert "5" ==            snapshot('5')                                                                                                                                                          |
++------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+These changes will be applied, because you used --inline-snapshot=fix
+----------------------------------------------------------------------------------------------- Problems -----------------------------------------------------------------------------------------------
+The format_command '/.../python3 fmt_cmd.py /.../test_a.py' caused the following error:
+some problem\
+"""
+            )
+        ),
+    )
+
+
+def test_no_black(mocker):
+
+    mocker.patch.dict(sys.modules, {"black": None})
+
+    Example(
+        {
+            "test_a.py": """
+from inline_snapshot import snapshot
+
+def test_a():
+    assert "5" ==            snapshot('''3''')
+""",
+        }
+    ).run_inline(
+        ["--inline-snapshot=fix"],
+        changed_files=snapshot(
+            {
+                "test_a.py": """\
+
+from inline_snapshot import snapshot
+
+def test_a():
+    assert "5" ==            snapshot('5')
+"""
+            }
+        ),
+        report=snapshot(
+            """\
+----------------------------------- Problems -----------------------------------
+inline-snapshot is not able to format your code.
+This issue can be solved by:
+ * installing inline-snapshot[black] which gives you the same formatting like in
+older versions
+ * adding a `format-command` to your pyproject.toml (see ⏎
+https://15r10nk.github.io/inline-snapshot/latest/configuration/#format-command ⏎
+for more information).
+
+
+"""
+        ),
+    )
diff --git a/tests/test_is_normalized.py b/tests/test_is_normalized.py
new file mode 100644
index 00000000..dea01ace
--- /dev/null
+++ b/tests/test_is_normalized.py
@@ -0,0 +1,31 @@
+from inline_snapshot import snapshot
+from inline_snapshot.testing._example import Example
+
+
+def test_repr():
+    Example(
+        """\
+from inline_snapshot import snapshot
+from tests._is_normalized import IsNormalized
+
+def test_a():
+    n=IsNormalized(sorted,snapshot())
+    assert [3,5,2] == n
+    assert repr(n)==snapshot()
+"""
+    ).run_inline(
+        ["--inline-snapshot=create"],
+        changed_files=snapshot(
+            {
+                "test_something.py": """\
+from inline_snapshot import snapshot
+from tests._is_normalized import IsNormalized
+
+def test_a():
+    n=IsNormalized(sorted,snapshot([2, 3, 5]))
+    assert [3,5,2] == n
+    assert repr(n)==snapshot("IsNormalized([2, 3, 5], should_be=[2, 3, 5])")
+"""
+            }
+        ),
+    )