add: --no-validate option to skip AST safety check (#496)

* fix(#50): add --no-validate

* refactor: use `dest=validate`

Co-authored-by: Taneli Hukkinen <[email protected]>

* refactor: finish renaming the stored value to validate

* test: add patch to unit test

* docs: add 'validate' to documentation

* docs: re-generate help on Python 3.13.1

* test: add valid configuration test

* fix: allow override

* Apply suggestions from code review

Co-authored-by: Taneli Hukkinen <[email protected]>

* ci: apply formatting

---------

Co-authored-by: Taneli Hukkinen <[email protected]>

Author: KyleKing

README.md

@@ -93,9 +93,10 @@ If a file is not properly formatted, the exit code will be non-zero.
 
 ```console
 foo@bar:~$ mdformat --help
-usage: mdformat [-h] [--check] [--version] [--number] [--wrap {keep,no,INTEGER}]
-                [--end-of-line {lf,crlf,keep}] [--exclude PATTERN]
-                [--extensions EXTENSION] [--codeformatters LANGUAGE]
+usage: mdformat [-h] [--check] [--no-validate] [--version] [--number]
+                [--wrap {keep,no,INTEGER}] [--end-of-line {lf,crlf,keep}]
+                [--exclude PATTERN] [--extensions EXTENSION]
+                [--codeformatters LANGUAGE]
                 [paths ...]
 
 CommonMark compliant Markdown formatter
@@ -106,19 +107,23 @@ positional arguments:
 options:
   -h, --help            show this help message and exit
   --check               do not apply changes to files
+  --no-validate         do not validate that the rendered HTML is consistent
   --version             show program's version number and exit
   --number              apply consecutive numbering to ordered lists
   --wrap {keep,no,INTEGER}
                         paragraph word wrap mode (default: keep)
   --end-of-line {lf,crlf,keep}
                         output file line ending mode (default: lf)
-  --exclude PATTERN     exclude files that match the Unix-style glob pattern (multiple allowed)
+  --exclude PATTERN     exclude files that match the Unix-style glob pattern
+                        (multiple allowed)
   --extensions EXTENSION
-                        require and enable an extension plugin (multiple allowed) (use
-                        `--no-extensions` to disable) (default: all enabled)
+                        require and enable an extension plugin (multiple
+                        allowed) (use `--no-extensions` to disable) (default:
+                        all enabled)
   --codeformatters LANGUAGE
-                        require and enable a code formatter plugin (multiple allowed)
-                        (use `--no-codeformatters` to disable) (default: all enabled)
+                        require and enable a code formatter plugin (multiple
+                        allowed) (use `--no-codeformatters` to disable)
+                        (default: all enabled)
 ```
 
 The `--exclude` option is only available on Python 3.13+.

docs/users/configuration_file.md

@@ -20,6 +20,7 @@ Command line interface arguments take precedence over the configuration file.
 wrap = "keep"         # options: {"keep", "no", INTEGER}
 number = false        # options: {false, true}
 end_of_line = "lf"    # options: {"lf", "crlf", "keep"}
+validate = true       # options: {false, true}
 # extensions = [      # options: a list of enabled extensions (default: all installed are enabled)
 #     "gfm",
 #     "toc",

src/mdformat/_cli.py

@@ -142,12 +142,16 @@ def run(cli_args: Sequence[str]) -> int:  # noqa: C901
                 getattr(plugin, "CHANGES_AST", False)
                 for plugin in enabled_parserplugins.values()
             )
-            if not changes_ast and not is_md_equal(
-                original_str,
-                formatted_str,
-                options=opts,
-                extensions=enabled_parserplugins,
-                codeformatters=enabled_codeformatters,
+            if (
+                opts["validate"]
+                and not changes_ast
+                and not is_md_equal(
+                    original_str,
+                    formatted_str,
+                    options=opts,
+                    extensions=enabled_parserplugins,
+                    codeformatters=enabled_codeformatters,
+                )
             ):
                 print_error(
                     f'Could not format "{path_str}".',
@@ -197,6 +201,13 @@ def make_arg_parser(
     parser.add_argument(
         "--check", action="store_true", help="do not apply changes to files"
     )
+    parser.add_argument(
+        "--no-validate",
+        action="store_const",
+        const=False,
+        dest="validate",
+        help="do not validate that the rendered HTML is consistent",
+    )
     version_str = f"mdformat {mdformat.__version__}"
     plugin_version_str = get_plugin_version_str(
         {**parser_extension_dists, **codeformatter_dists}

src/mdformat/_conf.py

@@ -10,6 +10,7 @@
     "wrap": "keep",
     "number": False,
     "end_of_line": "lf",
+    "validate": True,
     "exclude": [],
     "plugin": {},
     "extensions": None,
@@ -59,6 +60,9 @@ def _validate_values(opts: Mapping, conf_path: Path) -> None:  # noqa: C901
     if "end_of_line" in opts:
         if opts["end_of_line"] not in {"crlf", "lf", "keep"}:
             raise InvalidConfError(f"Invalid 'end_of_line' value in {conf_path}")
+    if "validate" in opts:
+        if not isinstance(opts["validate"], bool):
+            raise InvalidConfError(f"Invalid 'validate' value in {conf_path}")
     if "number" in opts:
         if not isinstance(opts["number"], bool):
             raise InvalidConfError(f"Invalid 'number' value in {conf_path}")

tests/test_cli.py

@@ -345,6 +345,19 @@ def test_eol__check_keep_crlf(tmp_path):
     assert run((str(file_path), "--check", "--end-of-line=keep")) == 1
 
 
+def test_cli_no_validate(tmp_path):
+    file_path = tmp_path / "test.md"
+    content = "1. ordered"
+    file_path.write_text(content)
+
+    with patch("mdformat.renderer._context.get_list_marker_type", return_value="?"):
+        assert run((str(file_path),)) == 1
+        assert file_path.read_text() == content
+
+        assert run((str(file_path), "--no-validate")) == 0
+        assert file_path.read_text() == "1? ordered\n"
+
+
 def test_get_plugin_info_str():
     info = get_plugin_info_str(
         {"mdformat-tables": ("0.1.0", ["tables"])},

tests/test_config_file.py

@@ -64,6 +64,7 @@ def test_invalid_toml(tmp_path, capsys):
     [
         ("wrap", "wrap = -3"),
         ("end_of_line", "end_of_line = 'lol'"),
+        ("validate", "validate = 'off'"),
         ("number", "number = 0"),
         ("exclude", "exclude = '**'"),
         ("exclude", "exclude = ['1',3]"),
@@ -149,3 +150,22 @@ def test_empty_exclude(tmp_path, capsys):
 
     assert run((str(tmp_path),)) == 0
     assert file1_path.read_text() == FORMATTED_MARKDOWN
+
+
+def test_conf_no_validate(tmp_path):
+    file_path = tmp_path / "file.md"
+    content = "1. ordered"
+    file_path.write_text(content)
+
+    with mock.patch(
+        "mdformat.renderer._context.get_list_marker_type",
+        return_value="?",
+    ):
+        assert run_with_clear_cache((str(file_path),)) == 1
+        assert file_path.read_text() == content
+
+        config_path = tmp_path / ".mdformat.toml"
+        config_path.write_text("validate = false")
+
+        assert run_with_clear_cache((str(file_path),)) == 0
+        assert file_path.read_text() == "1? ordered\n"