Add a few tests for pydoc.

This is a modified version of a patch proposed by Humberto Diogenes
in the discussion of issue1883.

I will merge manually this change into the py3k branch: the tests must be adapted.

Lib/test/test_pydoc.py

@@ -0,0 +1,33 @@
+from test import test_support
+import unittest
+import pydoc
+
+class TestDescriptions(unittest.TestCase):
+    def test_module(self):
+        # Check that pydocfodder module can be described
+        import pydocfodder
+        doc = pydoc.render_doc(pydocfodder)
+        assert "pydocfodder" in doc
+
+    def test_classic_class(self):
+        class C: "Classic class"
+        c = C()
+        self.failUnlessEqual(pydoc.describe(C), 'class C')
+        self.failUnlessEqual(pydoc.describe(c), 'instance of C')
+        self.failUnless('instance of C in module test.test_pydoc'
+                        in pydoc.render_doc(c))
+
+    def test_class(self):
+        class C(object): "New-style class"
+        c = C()
+
+        self.failUnlessEqual(pydoc.describe(C), 'class C')
+        self.failUnlessEqual(pydoc.describe(c), 'C')
+        self.failUnless('C in module test.test_pydoc object'
+                        in pydoc.render_doc(c))
+
+def test_main():
+    test_support.run_unittest(TestDescriptions)
+
+if __name__ == "__main__":
+    unittest.main()