[pylint.message] Add unittests for MessageDefinition

Author: Pierre-Sassoulas

pylint/message/message_definition.py

@@ -38,7 +38,10 @@ def __init__(
         self.old_names = old_names or []
 
     def __repr__(self):
-        return "MessageDefinition:{}".format(self.__dict__)
+        return "MessageDefinition:%s (%s)" % (self.symbol, self.msgid)
+
+    def __str__(self):
+        return "%s:\n%s %s" % (repr(self), self.msg, self.description)
 
     def may_be_emitted(self):
         """return True if message may be emitted using the current interpreter"""

tests/message/unittest_message_definition.py

@@ -0,0 +1,85 @@
+# -*- coding: utf-8 -*-
+
+# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+# For details: https://github.com/PyCQA/pylint/blob/master/COPYING
+
+import sys
+
+from pylint.checkers import BaseChecker
+from pylint.constants import WarningScope
+from pylint.message import MessageDefinition
+
+
+class FalseChecker(BaseChecker):
+    name = "FalseChecker"
+    msgs = {
+        "W1234": ("message one", "msg-symbol-one", "msg description"),
+        "W1235": (
+            "message two",
+            "msg-symbol-two",
+            "msg description",
+            {"old_names": [("W1230", "msg-symbol-one")]},
+        ),
+    }
+
+
+class TestMessagesDefinition(object):
+    def assert_with_fail_msg(self, msg, expected=True):
+        fail_msg = "With minversion='{}' and maxversion='{}',".format(
+            msg.minversion, msg.maxversion
+        )
+        fail_msg += " and the python interpreter being {} ".format(sys.version_info)
+        fail_msg += "the message should{}be emitable"
+        if expected:
+            assert msg.may_be_emitted(), fail_msg.format(" ")
+        else:
+            assert not msg.may_be_emitted(), fail_msg.format(" not ")
+
+    def get_message_definition(self):
+        args = [
+            FalseChecker(),
+            "W1234",
+            "message",
+            "description",
+            "msg-symbol",
+            WarningScope.NODE,
+        ]
+        kwargs = {"minversion": None, "maxversion": None}
+        return MessageDefinition(*args, **kwargs)
+
+    def test_may_be_emitted(self):
+        major = sys.version_info.major
+        minor = sys.version_info.minor
+        msg = self.get_message_definition()
+        self.assert_with_fail_msg(msg, expected=True)
+        msg.minversion = (major, minor - 1)
+        msg.maxversion = (major, minor + 1)
+        self.assert_with_fail_msg(msg, expected=True)
+        msg.minversion = (major, minor + 1)
+        self.assert_with_fail_msg(msg, expected=False)
+        msg.minversion = (major, minor - 1)
+        self.assert_with_fail_msg(msg, expected=True)
+        msg.maxversion = (major, minor - 1)
+        self.assert_with_fail_msg(msg, expected=False)
+
+    def test_repr(self):
+        msg = self.get_message_definition()
+        repr_str = str([msg, msg])
+        assert "W1234" in repr_str
+        assert "msg-symbol" in repr_str
+        expected = "[MessageDefinition:msg-symbol-one (W1234), MessageDefinition:msg-symbol-two (W1235)]"
+        assert str(FalseChecker().messages) == expected
+
+    def test_format_help(self):
+        msg = self.get_message_definition()
+        major = sys.version_info.major
+        minor = sys.version_info.minor
+        msg.minversion = (major, minor - 1)
+        msg.maxversion = (major, minor + 1)
+        format_str_checker_ref = msg.format_help(checkerref=False)
+        format_str = msg.format_help(checkerref=True)
+        assert str(minor - 1) in format_str
+        assert str(major + 1) in format_str_checker_ref
+        expected_format_help = """:msg-symbol-one (W1234): *message one*
+  msg description"""
+        assert FalseChecker().messages[0].format_help() == expected_format_help