Add InvalidCheckerError

3 files changed, 23 insertions, 4 deletions

diff --git a/pylint/exceptions.py b/pylint/exceptions.py
index 30640093f..6b217e0e2 100644
--- a/pylint/exceptions.py
+++ b/pylint/exceptions.py
@@ -25,5 +25,9 @@ class InvalidReporterError(Exception):
     """raised when selected reporter is invalid (e.g. not found)"""
 
 
+class InvalidCheckerError(Exception):
+    """raised when registering an invalid checker (e.g. invalid priority)"""
+
+
 class ConfigurationError(Exception):
     """Raised when the configuration is invalid."""
diff --git a/pylint/lint.py b/pylint/lint.py
index 7e5770375..c9a69e804 100644
--- a/pylint/lint.py
+++ b/pylint/lint.py
@@ -928,12 +928,12 @@ class PluginRegistry(utils.ReportsHandlerMixIn):
         :param checker: The checker to register.
         :type checker: BaseChecker
 
-        :raises ValueError: If the priority of the checker is invalid.
+        :raises InvalidCheckerError: If the priority of the checker is
+            invalid.
         """
         if checker.priority > 0:
-            # TODO: Use a custom exception
             msg = "{}.priority must be <= 0".format(checker.__class__)
-            raise ValueError(msg)
+            raise exceptions.InvalidCheckerError(msg)
 
         self._checkers[checker.name].append(checker)
 
diff --git a/pylint/test/unittest_lint.py b/pylint/test/unittest_lint.py
index 072df1744..ab73d04bc 100644
--- a/pylint/test/unittest_lint.py
+++ b/pylint/test/unittest_lint.py
@@ -48,7 +48,11 @@ from pylint.utils import (
     FileState,
     tokenize_module,
 )
-from pylint.exceptions import InvalidMessageError, UnknownMessageError
+from pylint.exceptions import (
+    InvalidCheckerError,
+    InvalidMessageError,
+    UnknownMessageError,
+)
 import pylint.testutils as testutils
 from pylint.reporters import text
 from pylint import checkers
@@ -252,6 +256,17 @@ def init_linter(linter):
     return linter
 
 
+def test_register_checker_invalid_priority():
+    class CustomChecker(checkers.BaseChecker):
+        priority = 10
+
+    linter = PyLinter()
+    plugin_registry = PluginRegistry(linter)
+
+    with pytest.raises(exceptions.InvalidCheckerError):
+        plugin_registry.register_checker(CustomChecker(linter))
+
+
 def test_pylint_visit_method_taken_in_account(linter):
     class CustomChecker(checkers.BaseChecker):
         __implements__ = interfaces.IAstroidChecker