nikola kramaric fix #5975, Abstract intermediate class not recognized as such

4 files changed, 28 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 1f6a1da..65e89b7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -10,6 +10,8 @@ ChangeLog for PyLint
 
     * fix #20991, class scope definitions ignored in a genexpr
 
+    * fix #5975, Abstract intermediate class not recognized as such
+
     * fix #5977, yield and return statement have their own counters, no more R0911
       (Too many return statements) when a function have many yield stamtements
 
diff --git a/checkers/classes.py b/checkers/classes.py
index 6494e27..b722742 100644
--- a/checkers/classes.py
+++ b/checkers/classes.py
@@ -24,6 +24,17 @@ from pylint.interfaces import IASTNGChecker
 from pylint.checkers import BaseChecker
 from pylint.checkers.utils import PYMETHODS, overrides_a_method
 
+def class_is_abstract(node):
+    """return true if the given class node should be considered as an abstract
+    class
+    """
+    for method in node.methods():
+        if method.parent.frame() is node:
+            if method.is_abstract(pass_is_abstract=False):
+                return True
+    return False
+
+
 MSGS = {
     'F0202': ('Unable to check methods signature (%s / %s)',
               'Used when PyLint has been unable to check methods signature \
@@ -369,6 +380,9 @@ instance attributes.'}
         """check that the given class node implements abstract methods from
         base classes
         """
+        # check if this class abstract
+        if class_is_abstract(node):
+            return
         for method in node.methods():
             owner = method.parent.frame()
             if owner is node:
diff --git a/test/input/func_w0223.py b/test/input/func_w0223.py
index e1e81bf..0682172 100644
--- a/test/input/func_w0223.py
+++ b/test/input/func_w0223.py
@@ -19,6 +19,15 @@ class Abstract:
     def __init__(self):
         pass
 
+class AbstractB(Abstract):
+    """abstract class
+    this class is checking that it does not output an error msg for
+    unimplemeted methods in abstract classes
+    """
+    def cccc(self):
+        """should be overridden in concrete class"""
+        raise NotImplementedError()
+
 class Concret(Abstract):
     """concret class"""
 
diff --git a/test/messages/func_w0223.txt b/test/messages/func_w0223.txt
index fc735da..943cf03 100644
--- a/test/messages/func_w0223.txt
+++ b/test/messages/func_w0223.txt
@@ -1,2 +1,4 @@
-W: 22:Concret: Method 'bbbb' is abstract in class 'Abstract' but is not overridden
+R: 22:AbstractB: Abstract class not referenced
+W: 31:Concret: Method 'bbbb' is abstract in class 'Abstract' but is not overridden
+