1 files changed, 194 insertions, 0 deletions
diff --git a/src/ansiblelint/_internal/rules.py b/src/ansiblelint/_internal/rules.py
new file mode 100644
index 0000000..4d0bf49
--- /dev/null
+++ b/src/ansiblelint/_internal/rules.py
@@ -0,0 +1,194 @@
+"""Internally used rule classes."""
+from __future__ import annotations
+
+import inspect
+import logging
+from pathlib import Path
+from typing import TYPE_CHECKING, Any
+
+from ansiblelint.constants import RULE_DOC_URL
+
+if TYPE_CHECKING:
+    from ansiblelint.errors import MatchError
+    from ansiblelint.file_utils import Lintable
+    from ansiblelint.rules import RulesCollection
+
+_logger = logging.getLogger(__name__)
+LOAD_FAILURE_MD = """\
+# load-failure
+
+"Linter failed to process a file, possible invalid file. Possible reasons:
+
+* contains unsupported encoding (only UTF-8 is supported)
+* not an Ansible file
+* it contains some unsupported custom YAML objects (`!!` prefix)
+* it was not able to decrypt an inline `!vault` block.
+
+This violation **is not** skippable, so it cannot be added to the `warn_list`
+or the `skip_list`. If a vault decryption issue cannot be avoided, the
+offending file can be added to `exclude_paths` configuration.
+"""
+
+
+# Derived rules are likely to want to access class members, so:
+# pylint: disable=unused-argument
+class BaseRule:
+    """Root class used by Rules."""
+
+    id: str = ""
+    tags: list[str] = []
+    description: str = ""
+    version_added: str = ""
+    severity: str = ""
+    link: str = ""
+    has_dynamic_tags: bool = False
+    needs_raw_task: bool = False
+    # We use _order to sort rules and to ensure that some run before others,
+    # _order 0 for internal rules
+    # _order 1 for rules that check that data can be loaded
+    # _order 5 implicit for normal rules
+    _order: int = 5
+    _help: str | None = None
+    # Added when a rule is registered into a collection, gives access to options
+    _collection: RulesCollection | None = None
+
+    @property
+    def help(self) -> str:
+        """Return a help markdown string for the rule."""
+        if self._help is None:
+            self._help = ""
+            md_file = (
+                Path(inspect.getfile(self.__class__)).parent
+                / f"{self.id.replace('-', '_')}.md"
+            )
+            if md_file.exists():
+                self._help = md_file.read_text(encoding="utf-8")
+        return self._help
+
+    @property
+    def url(self) -> str:
+        """Return rule documentation url."""
+        url = self.link
+        if not url:  # pragma: no cover
+            url = RULE_DOC_URL
+            if self.id:
+                url += self.id + "/"
+        return url
+
+    @property
+    def shortdesc(self) -> str:
+        """Return the short description of the rule, basically the docstring."""
+        return self.__doc__ or ""
+
+    def getmatches(self, file: Lintable) -> list[MatchError]:
+        """Return all matches while ignoring exceptions."""
+        matches = []
+        if not file.path.is_dir():
+            for method in [self.matchlines, self.matchtasks, self.matchyaml]:
+                try:
+                    matches.extend(method(file))
+                except Exception as exc:  # pylint: disable=broad-except
+                    _logger.warning(
+                        "Ignored exception from %s.%s while processing %s: %s",
+                        self.__class__.__name__,
+                        method,
+                        str(file),
+                        exc,
+                    )
+        else:
+            matches.extend(self.matchdir(file))
+        return matches
+
+    def matchlines(self, file: Lintable) -> list[MatchError]:
+        """Return matches found for a specific line."""
+        return []
+
+    def matchtask(
+        self, task: dict[str, Any], file: Lintable | None = None
+    ) -> bool | str | MatchError | list[MatchError]:
+        """Confirm if current rule is matching a specific task.
+
+        If ``needs_raw_task`` (a class level attribute) is ``True``, then
+        the original task (before normalization) will be made available under
+        ``task["__raw_task__"]``.
+        """
+        return False
+
+    def matchtasks(self, file: Lintable) -> list[MatchError]:
+        """Return matches for a tasks file."""
+        return []
+
+    def matchyaml(self, file: Lintable) -> list[MatchError]:
+        """Return matches found for a specific YAML text."""
+        return []
+
+    def matchplay(self, file: Lintable, data: dict[str, Any]) -> list[MatchError]:
+        """Return matches found for a specific playbook."""
+        return []
+
+    def matchdir(self, lintable: Lintable) -> list[MatchError]:
+        """Return matches for lintable folders."""
+        return []
+
+    def verbose(self) -> str:
+        """Return a verbose representation of the rule."""
+        return self.id + ": " + self.shortdesc + "\n  " + self.description
+
+    def match(self, line: str) -> bool | str:
+        """Confirm if current rule matches the given string."""
+        return False
+
+    def __lt__(self, other: BaseRule) -> bool:
+        """Enable us to sort rules by their id."""
+        return (self._order, self.id) < (other._order, other.id)
+
+    def __repr__(self) -> str:
+        """Return a AnsibleLintRule instance representation."""
+        return self.id + ": " + self.shortdesc
+
+
+# pylint: enable=unused-argument
+
+
+class RuntimeErrorRule(BaseRule):
+    """Unexpected internal error."""
+
+    id = "internal-error"
+    severity = "VERY_HIGH"
+    tags = ["core"]
+    version_added = "v5.0.0"
+    _order = 0
+
+
+class AnsibleParserErrorRule(BaseRule):
+    """AnsibleParserError."""
+
+    id = "parser-error"
+    description = "Ansible parser fails; this usually indicates an invalid file."
+    severity = "VERY_HIGH"
+    tags = ["core"]
+    version_added = "v5.0.0"
+    _order = 0
+
+
+class LoadingFailureRule(BaseRule):
+    """Failed to load or parse file."""
+
+    id = "load-failure"
+    description = "Linter failed to process a file, possible invalid file."
+    severity = "VERY_HIGH"
+    tags = ["core", "unskippable"]
+    version_added = "v4.3.0"
+    help = LOAD_FAILURE_MD
+    _order = 0
+
+
+class WarningRule(BaseRule):
+    """Other warnings detected during run."""
+
+    id = "warning"
+    severity = "LOW"
+    # should remain experimental as that would keep it warning only
+    tags = ["core", "experimental"]
+    version_added = "v6.8.0"
+    _order = 0