Makes .mdformat.toml take precedence (#20)

* Makes `.mdformat.toml` takes precedence

Closes #17

* Improve tests to cover all scenarios

* Use 2 separate files to test pyproject.toml and .mdproject.toml via pre-commit

* Fix pre-commit-test regex

---------

Co-authored-by: Carles Sala <[email protected]>

Author: kdeldycke

.pre-commit-config.yaml

@@ -29,7 +29,7 @@ repos:
     - flake8-builtins
     - flake8-comprehensions
 - repo: https://github.com/hukkin/mdformat
-  rev: 0.7.21
+  rev: 1.0.0
   hooks:
   - id: mdformat
     additional_dependencies:

.pre-commit-test.yaml

@@ -4,6 +4,6 @@ repos:
     - id: mdformat
       name: mdformat
       entry: mdformat
-      files: "tests/pre-commit-test.md"
+      files: ".*/pre-commit-test.md"
       types: [markdown]
       language: system

mdformat_pyproject/plugin.py

@@ -8,6 +8,7 @@
 
 import markdown_it
 import mdformat
+from mdformat._cli import print_paragraphs
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
@@ -23,63 +24,94 @@
     import tomli as tomllib
 
 
-@cache
-def _find_pyproject_toml_path(search_path: Path) -> Path | None:
-    """Find the pyproject.toml file that applies to the search path.
-
-    The search is done ascending through the folders tree until a pyproject.toml
-    file is found in the same folder. If the root '/' is reached, None is returned.
-    """
-    if search_path.is_file():
-        search_path = search_path.parent
-
-    for parent in (search_path, *search_path.parents):
-        candidate = parent / "pyproject.toml"
-        if candidate.is_file():
-            return candidate
-
-    return None
-
-
 @cache
 def _parse_pyproject(pyproject_path: Path) -> _ConfigOptions | None:
-    """Extract and validate the mdformat options from the pyproject.toml file.
+    """Extract and validate the mdformat options from the ``pyproject.toml`` file.
+
+    The options are searched inside a ``[tool.mdformat]`` section within the TOML file,
+    and they are validated using the default functions from ``mdformat._conf``.
 
-    The options are searched inside a [tool.mdformat] key within the toml file,
-    and they are validated using the default functions from `mdformat._conf`.
+    If no ``[tool.mdformat]`` section is found, ``None`` is returned.
     """
     with pyproject_path.open(mode="rb") as pyproject_file:
-        content = tomllib.load(pyproject_file)
+        try:
+            content = tomllib.load(pyproject_file)
+        except tomllib.TOMLDecodeError as e:
+            raise mdformat._conf.InvalidConfError(f"Invalid TOML syntax: {e}")
 
     options = content.get("tool", {}).get("mdformat")
-    if options is not None:
-        mdformat._conf._validate_keys(options, pyproject_path)
-        mdformat._conf._validate_values(options, pyproject_path)
+    if options is None:
+        return None
+
+    mdformat._conf._validate_keys(options, pyproject_path)
+    mdformat._conf._validate_values(options, pyproject_path)
 
     return options
 
 
+_orig_read_toml_opts = mdformat._conf.read_toml_opts
+
+
 @cache
-def read_toml_opts(conf_dir: Path) -> tuple[dict, Path | None]:
-    """Alternative read_toml_opts that reads from pyproject.toml instead of .mdformat.toml.
+def patched_read_toml_opts(search_path: Path) -> tuple[dict, Path | None]:
+    """Patched version of ``mdformat._conf.read_toml_opts``.
+
+    Search the first ``.mdformat.toml`` or ``pyproject.toml`` file in the provided
+    ``search_path`` folder or its parents.
+
+    The search is done ascending through the folders tree until a ``.mdformat.toml`` or a
+    ``pyproject.toml`` file is found. If the root ``/`` is reached, ``None`` is returned.
 
-    Notice that if `.mdformat.toml` exists it is ignored.
+    ``.mdformat.toml`` takes precedence over ``pyproject.toml`` if both are present in the
+    same folder. In that case, a warning is logged to inform the user that the
+    ``pyproject.toml`` file has been ignored.
+
+    ``pyproject.toml`` files without a ``[tool.mdformat]`` section are ignored.
+
+    This behavior mimics the one from Ruff, as described in `issues#17
+    <https://github.com/csala/mdformat-pyproject/issues/17>`_.
     """
-    pyproject_path = _find_pyproject_toml_path(conf_dir)
-    if pyproject_path:
-        pyproject_opts = _parse_pyproject(pyproject_path)
-    else:
-        pyproject_opts = {}
+    if search_path.is_file():
+        search_path = search_path.parent
 
-    return pyproject_opts, pyproject_path
+    for parent in (search_path, *search_path.parents):
+        # Try to find a pyproject.toml file first, with a [tool.mdformat] section.
+        pyproject_options = None
+        pyproject_path = parent / "pyproject.toml"
+        if pyproject_path.is_file():
+            pyproject_options = _parse_pyproject(pyproject_path)
+
+        # Read options from .mdformat.toml if present.
+        mdformat_path = parent / ".mdformat.toml"
+        if mdformat_path.is_file():
+            # If both pyproject.toml and .mdformat.toml are present, the latter takes
+            # precedence, but we warn the user that pyproject.toml is being ignored.
+            if pyproject_options is not None:
+                print_paragraphs(
+                    (
+                        f"Warning: ignoring mdformat options from {pyproject_path} "
+                        f"since {mdformat_path} is present.",
+                    )
+                )
+
+            # Return options from .mdformat.toml using the original function, even if
+            # they are empty.
+            return _orig_read_toml_opts(mdformat_path.parent)
+
+        # Return options from pyproject.toml if .mdformat.toml is not present.
+        elif pyproject_options is not None:
+            return pyproject_options, pyproject_path
+
+    # No config file found, return empty options.
+    return {}, None
 
 
 def update_mdit(mdit: markdown_it.MarkdownIt) -> None:
-    """No-op, since this plugin only monkey patches and does not modify mdit."""
+    """No-op, since this plugin only monkey patches and does not modify ``mdit``."""
     pass
 
 
 RENDERERS: dict[str, Render] = {}
 
 # Monkey patch mdformat._conf to use our own read_toml_opts version
-mdformat._conf.read_toml_opts = read_toml_opts
+mdformat._cli.read_toml_opts = patched_read_toml_opts

.mdformat.toml renamed to tests/mdformat_toml/.mdformat.toml

@@ -0,0 +1,16 @@
+# Test file
+
+This repository contains 2 separate configuration files with contradictory
+settings:
+
+1. The `tests/mdformat_toml/.mdformat.toml`, which defines a `wrap` length of 80
+   and sets `number` to `false`, meaning that numbered lists would be written
+   starting with `1.` on all the rows.
+1. The `pyproject.toml`, which should be used after the `mdformat-pyproject`
+   plugin is installed, and which defines wrap length of 99 and sets `number` to
+   `true`, meaning that numbered lists would be written starting with
+   consecutive numbers.
+
+This file is written according to the rules specified in the `.mdformat.toml`
+file placed alongside it, and serves as a valid test to see if the plugin is
+working as expected and honoring `.mdformat.toml` when found.

tests/mdformat_toml/pre-commit-test.md

@@ -2,9 +2,8 @@
 
 This repository contains 2 separate configuration files with contradictory settings:
 
-1. The `.mdformat.toml`, which should be used by default by `mdformat`, and which defines a `wrap`
-   length of 80 and sets `number` to `false`, meaning that numbered lists would be written starting
-   with `1.` on all the rows.
+1. The `tests/mdformat_toml/.mdformat.toml`, which defines a `wrap` length of 80 and sets `number`
+   to `false`, meaning that numbered lists would be written starting with `1.` on all the rows.
 2. The `pyproject.toml`, which should be used after the `mdformat-pyproject` plugin is installed,
    and which defines wrap length of 99 and sets `number` to `true`, meaning that numbered lists
    would be written starting with consecutive numbers.