Make renderText gracefully handle non-str values. Fixes #16

CHANGES.rst

@@ -11,6 +11,10 @@
   ``None``. This can be the case with namespace packages, especially
   under Python 3.7. See `issue #17 <https://github.com/zopefoundation/zope.app.apidoc/issues/17>`_.
 
+- Rendering documentation for a class that has a ``__doc__`` property
+  no longer fails but produces a descriptive message. See `issue 16
+  <https://github.com/zopefoundation/zope.app.apidoc/issues/16>`_.
+
 - Host documentation at https://zopeappapidoc.readthedocs.io/
 
 - Add argument to ``static-apidoc`` for loading a specific ZCML file. To use this feature, the ZCML file you specify needs to

src/zope/app/apidoc/codemodule/browser/tests.py

@@ -15,6 +15,7 @@
 
 """
 import unittest
+from BTrees import OOBTree
 
 from zope.traversing.api import traverse
 
@@ -107,7 +108,7 @@ def testZCMLFileDetailsView(self):
             body, '/++apidoc++/Code/zope/app/apidoc/configure.zcml/index.html',
             basic='mgr:mgrpw')
 
-from BTrees import OOBTree
+
 class TestClass(unittest.TestCase):
 
     layer = APIDocLayer
@@ -128,6 +129,26 @@ def test_listClasses_C(self):
         info = details._listClasses([items_class])
         self.assertIsNone(info[0]['url'], None)
 
+    def test_not_fail_with_doc_property(self):
+        from zope.app.apidoc.codemodule.browser.class_ import ClassDetails
+        from zope.app.apidoc.codemodule.class_ import Class
+
+        # Such as in zope.hookable._py_hookable
+        class WithProperty(object):
+            @property
+            def __doc__(self):
+                return "Some Docs"
+
+        class Parent(object):
+            def getPath(self):
+                return '/'
+
+        details = ClassDetails()
+        details.context = Class(Parent(), WithProperty.__name__, WithProperty)
+
+        self.assertIn('Failed to render non-text', details.getDoc())
+
+
 class TestIntrospectorNS(unittest.TestCase):
 
     def _check_namespace(self, kind, context, name):

src/zope/app/apidoc/tests.py

@@ -236,6 +236,15 @@ def test_keyword_only_arguments(self):
                 '()',
                 getFunctionSignature(TestUtilities.test_keyword_only_arguments))
 
+    def test_renderText_non_text(self):
+        # If we pass something that isn't actually text, we get a
+        # descriptive error back.
+        from zope.app.apidoc.utilities import renderText
+
+        text = renderText(self)
+        self.assertIn("Failed to render non-text", text)
+
+
 from zope.app.apidoc import static
 
 class TestStatic(unittest.TestCase):

src/zope/app/apidoc/utilities.py

@@ -370,6 +370,7 @@ def dedentString(text):
 
 
 def renderText(text, module=None, format=None, dedent=True):
+    # dedent is ignored, we always dedent
     if not text:
         return u''
 
@@ -387,7 +388,11 @@ def renderText(text, module=None, format=None, dedent=True):
     if isinstance(text, bytes):
         text = text.decode('utf-8', 'replace')
 
-    text = dedentString(text)
+    try:
+        text = dedentString(text)
+    except TypeError as e:
+        return u'Failed to render non-text (%r): %s' %(text, e,)
+
     source = createObject(format, text)
 
     renderer = getMultiAdapter((source, TestRequest()))