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

README.md

@@ -93,10 +93,9 @@ 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]
-                [paths ...]
+usage: mdformat [-h] [--check] [--no-validate] [--version] [--number]
+                [--wrap {keep,no,INTEGER}] [--end-of-line {lf,crlf,keep}]
+                [--extensions EXTENSION] [--codeformatters LANGUAGE] [paths ...]
 
 CommonMark compliant Markdown formatter
 
@@ -106,6 +105,7 @@ 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}

src/mdformat/_cli.py

@@ -143,12 +143,16 @@ 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 (
+                not opts["no_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}".',
@@ -198,6 +202,11 @@ 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_true",
+        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

@@ -8,6 +8,7 @@
 
 DEFAULT_OPTS = {
     "wrap": "keep",
+    "no_validate": False,
     "number": False,
     "end_of_line": "lf",
     "exclude": [],
@@ -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 "no_validate" in opts:
+        if not isinstance(opts["no_validate"], bool):
+            raise InvalidConfError(f"Invalid 'no_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 +345,21 @@ def test_eol__check_keep_crlf(tmp_path):
     assert run((str(file_path), "--check", "--end-of-line=keep")) == 1
 
 
+@pytest.mark.skip
+def test_no_validate(tmp_path):
+    # FIXME: Fake an mdformat bug that renders to a different HTML
+
+    file_path = tmp_path / "test.md"
+    content = "2. ordered"
+    file_path.write_text(content)
+
+    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() != content
+
+
 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'"),
+        ("no_validate", "no_validate = 1"),
         ("number", "number = 0"),
         ("exclude", "exclude = '**'"),
         ("exclude", "exclude = ['1',3]"),