Don't emit 'missing-docstring' when the actual docstring uses `.format`. Closes issue #281.

5 files changed, 106 insertions, 81 deletions

diff --git a/ChangeLog b/ChangeLog
index ea1962a..d4f7c86 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -79,6 +79,9 @@ ChangeLog for Pylint
     * Don't emit 'unnecessary-lambda' if the body of the lambda call contains
       call chaining. Closes issue #243.
 
+    * Don't emit 'missing-docstring' when the actual docstring uses `.format`.
+      Closes issue #281.
+
 
 2014-04-30  --  1.2.1
     * Restore the ability to specify the init-hook option via the
diff --git a/checkers/base.py b/checkers/base.py
index fb63c51..c1600b5 100644
--- a/checkers/base.py
+++ b/checkers/base.py
@@ -53,6 +53,7 @@ REVERSED_METHODS = (('__getitem__', '__len__'),
                     ('__reversed__', ))
 
 PY33 = sys.version_info >= (3, 3)
+PY3K = sys.version_info >= (3, 0)
 BAD_FUNCTIONS = ['map', 'filter', 'apply']
 if sys.version_info < (3, 0):
     BAD_FUNCTIONS.append('input')
@@ -1092,6 +1093,17 @@ class DocStringChecker(_BasicChecker):
             if node_type != 'module' and max_lines > -1 and lines < max_lines:
                 return
             self.stats['undocumented_'+node_type] += 1
+            if (node.body and isinstance(node.body[0], astroid.Discard) and
+                isinstance(node.body[0].value, astroid.CallFunc)):
+                # Most likely a string with a format call. Let's see.
+                func = safe_infer(node.body[0].value.func)
+                if (isinstance(func, astroid.BoundMethod)
+                    and isinstance(func.bound, astroid.Instance)):
+                    # Strings in Python 3, others in Python 2.
+                    if PY3K and func.bound.name == 'str':
+                        return
+                    elif func.bound.name in ('str', 'unicode', 'bytes'):
+                        return
             self.add_message('missing-docstring', node=node, args=(node_type,))
         elif not docstring.strip():
             self.stats['undocumented_'+node_type] += 1
diff --git a/test/input/func_docstring.py b/test/functional/docstrings.py
index e73d8a3..9ef09f5 100644
--- a/test/input/func_docstring.py
+++ b/test/functional/docstrings.py
@@ -1,73 +1,83 @@
-# pylint: disable=R0201
-
-__revision__ = ''
-
-def function0():
-    """"""
-
-def function1(value):
-    # missing docstring
-    print value
-
-def function2(value):
-    """docstring"""
-    print value
-
-def function3(value):
-    """docstring"""
-    print value
-
-class AAAA(object):
-    # missing docstring
-
-##     class BBBB:
-##         # missing docstring
-##         pass
-
-##     class CCCC:
-##         """yeah !"""
-##         def method1(self):
-##             pass
-
-##         def method2(self):
-##             """ yeah !"""
-##             pass
-
-    def method1(self):
-        pass
-
-    def method2(self):
-        """ yeah !"""
-        pass
-
-    def method3(self):
-        """"""
-        pass
-
-    def __init__(self):
-        pass
-
-class DDDD(AAAA):
-    """yeah !"""
-
-    def __init__(self):
-        AAAA.__init__(self)
-
-    def method2(self):
-        """"""
-        pass
-
-    def method3(self):
-        pass
-
-    def method4(self):
-        pass
-
-# pylint: disable=missing-docstring
-def function4():
-    pass
-
-# pylint: disable=empty-docstring
-def function5():
-    """"""
-    pass
+# pylint: disable=R0201

+# -1: [missing-docstring]

+__revision__ = ''

+

+# +1: [empty-docstring]

+def function0():

+    """"""

+

+# +1: [missing-docstring]

+def function1(value):

+    # missing docstring

+    print(value)

+

+def function2(value):

+    """docstring"""

+    print(value)

+

+def function3(value):

+    """docstring"""

+    print(value)

+

+# +1: [missing-docstring]

+class AAAA(object):

+    # missing docstring

+

+##     class BBBB:

+##         # missing docstring

+##         pass

+

+##     class CCCC:

+##         """yeah !"""

+##         def method1(self):

+##             pass

+

+##         def method2(self):

+##             """ yeah !"""

+##             pass

+

+    # +1: [missing-docstring]

+    def method1(self):

+        pass

+

+    def method2(self):

+        """ yeah !"""

+        pass

+

+    # +1: [empty-docstring]

+    def method3(self):

+        """"""

+        pass

+

+    def __init__(self):

+        pass

+

+class DDDD(AAAA):

+    """yeah !"""

+

+    def __init__(self):

+        AAAA.__init__(self)

+

+    # +1: [empty-docstring]

+    def method2(self):

+        """"""

+        pass

+

+    def method3(self):

+        pass

+

+    # +1: [missing-docstring]

+    def method4(self):

+        pass

+

+# pylint: disable=missing-docstring

+def function4():

+    pass

+

+# pylint: disable=empty-docstring

+def function5():

+    """"""

+    pass

+

+def function6():

+    """ I am a {} docstring.""".format("good")

diff --git a/test/functional/docstrings.txt b/test/functional/docstrings.txt
new file mode 100644
index 0000000..1ea5c7d
--- /dev/null
+++ b/test/functional/docstrings.txt
@@ -0,0 +1,8 @@
+missing-docstring:1::Missing module docstring

+empty-docstring:6:function0:Empty function docstring

+missing-docstring:10:function1:Missing function docstring

+missing-docstring:23:AAAA:Missing class docstring

+missing-docstring:40:AAAA.method1:Missing method docstring

+empty-docstring:48:AAAA.method3:Empty method docstring

+empty-docstring:62:DDDD.method2:Empty method docstring

+missing-docstring:70:DDDD.method4:Missing method docstring

diff --git a/test/messages/func_docstring.txt b/test/messages/func_docstring.txt
deleted file mode 100644
index 932df5e..0000000
--- a/test/messages/func_docstring.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-C:  1: Missing module docstring
-C:  5:function0: Empty function docstring
-C:  8:function1: Missing function docstring
-C: 20:AAAA: Missing class docstring
-C: 36:AAAA.method1: Missing method docstring
-C: 43:AAAA.method3: Empty method docstring
-C: 56:DDDD.method2: Empty method docstring
-C: 63:DDDD.method4: Missing method docstring