Revert r77730 and add back verify and vereq in case other projects use them,...

Revert r77730 and add back verify and vereq in case other projects use them, but leave the changes in test_pprint and string_tests.

Lib/test/test_support.py

@@ -17,7 +17,7 @@ __all__ = ["Error", "TestFailed", "TestSkipped", "ResourceDenied", "import_modul
            "get_original_stdout", "unload", "unlink", "rmtree", "forget",
            "is_resource_enabled", "requires", "find_unused_port", "bind_port",
            "fcmp", "have_unicode", "is_jython", "TESTFN", "HOST", "FUZZ",
-           "findfile", "sortdict", "check_syntax_error",
+           "findfile", "verify", "vereq", "sortdict", "check_syntax_error",
            "open_urlresource", "check_warnings", "CleanImport",
            "EnvironmentVarGuard", "captured_output",
            "captured_stdout", "TransientResource", "transient_internet",
@@ -325,6 +325,30 @@ def findfile(file, here=__file__):
         if os.path.exists(fn): return fn
     return file
 
+def verify(condition, reason='test failed'):
+    """Verify that condition is true. If not, raise TestFailed.
+
+       The optional argument reason can be given to provide
+       a better error text.
+    """
+
+    if not condition:
+        raise TestFailed(reason)
+
+def vereq(a, b):
+    """Raise TestFailed if a == b is false.
+
+    This is better than verify(a == b) because, in case of failure, the
+    error message incorporates repr(a) and repr(b) so you can see the
+    inputs.
+
+    Note that "not (a == b)" isn't necessarily the same as "a != b"; the
+    former is tested.
+    """
+
+    if not (a == b):
+        raise TestFailed("%r == %r" % (a, b))
+
 def sortdict(dict):
     "Like repr(dict), but in sorted order."
     items = dict.items()