1 files changed, 81 insertions, 0 deletions
diff --git a/lib/ansiblelint/errors.py b/lib/ansiblelint/errors.py
new file mode 100644
index 0000000..8569dca
--- /dev/null
+++ b/lib/ansiblelint/errors.py
@@ -0,0 +1,81 @@
+"""Exceptions and error representations."""
+import functools
+
+from ansiblelint.file_utils import normpath
+
+
+@functools.total_ordering
+class MatchError(ValueError):
+    """Rule violation detected during linting.
+
+    It can be raised as Exception but also just added to the list of found
+    rules violations.
+
+    Note that line argument is not considered when building hash of an
+    instance.
+    """
+
+    # IMPORTANT: any additional comparison protocol methods must return
+    # IMPORTANT: `NotImplemented` singleton to allow the check to use the
+    # IMPORTANT: other object's fallbacks.
+    # Ref: https://docs.python.org/3/reference/datamodel.html#object.__lt__
+
+    def __init__(
+            self,
+            message=None,
+            linenumber=0,
+            details: str = "",
+            filename=None,
+            rule=None) -> None:
+        """Initialize a MatchError instance."""
+        super().__init__(message)
+
+        if not (message or rule):
+            raise TypeError(
+                f'{self.__class__.__name__}() missing a '
+                "required argument: one of 'message' or 'rule'",
+            )
+
+        self.message = message or getattr(rule, 'shortdesc', "")
+        self.linenumber = linenumber
+        self.details = details
+        self.filename = normpath(filename) if filename else None
+        self.rule = rule
+        self.ignored = False  # If set it will be displayed but not counted as failure
+
+    def __repr__(self):
+        """Return a MatchError instance representation."""
+        formatstr = u"[{0}] ({1}) matched {2}:{3} {4}"
+        # note that `rule.id` can be int, str or even missing, as users
+        # can defined their own custom rules.
+        _id = getattr(self.rule, "id", "000")
+
+        return formatstr.format(_id, self.message,
+                                self.filename, self.linenumber, self.details)
+
+    @property
+    def _hash_key(self):
+        # line attr is knowingly excluded, as dict is not hashable
+        return (
+            self.filename,
+            self.linenumber,
+            str(getattr(self.rule, 'id', 0)),
+            self.message,
+            self.details,
+        )
+
+    def __lt__(self, other):
+        """Return whether the current object is less than the other."""
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+        return self._hash_key < other._hash_key
+
+    def __hash__(self):
+        """Return a hash value of the MatchError instance."""
+        return hash(self._hash_key)
+
+    def __eq__(self, other):
+        """Identify whether the other object represents the same rule match."""
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+        return self.__hash__() == other.__hash__()