--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-doctest.py	Thu Nov 30 14:48:54 2017 -0800
@@ -0,0 +1,49 @@
+# this is hack to make sure no escape characters are inserted into the output
+
+from __future__ import absolute_import
+
+import doctest
+import os
+import re
+import sys
+
+ispy3 = (sys.version_info[0] >= 3)
+
+# add hggit/ to sys.path
+sys.path.insert(0, os.path.join(os.environ["TESTDIR"], ".."))
+
+if 'TERM' in os.environ:
+    del os.environ['TERM']
+
+class py3docchecker(doctest.OutputChecker):
+    def check_output(self, want, got, optionflags):
+        want2 = re.sub(r'''\bu(['"])(.*?)\1''', r'\1\2\1', want)  # py2: u''
+        got2 = re.sub(r'''\bb(['"])(.*?)\1''', r'\1\2\1', got)  # py3: b''
+        # py3: <exc.name>: b'<msg>' -> <name>: <msg>
+        #      <exc.name>: <others> -> <name>: <others>
+        got2 = re.sub(r'''^hggit\.\w+\.(\w+): (['"])(.*?)\2''', r'\1: \3',
+                      got2, re.MULTILINE)
+        got2 = re.sub(r'^hggit\.\w+\.(\w+): ', r'\1: ', got2, re.MULTILINE)
+        return any(doctest.OutputChecker.check_output(self, w, g, optionflags)
+                   for w, g in [(want, got), (want2, got2)])
+
+def testmod(name, optionflags=0, testtarget=None):
+    __import__(name)
+    mod = sys.modules[name]
+    if testtarget is not None:
+        mod = getattr(mod, testtarget)
+
+    # minimal copy of doctest.testmod()
+    finder = doctest.DocTestFinder()
+    checker = None
+    if ispy3:
+        checker = py3docchecker()
+    runner = doctest.DocTestRunner(checker=checker, optionflags=optionflags)
+    for test in finder.find(mod, name):
+        runner.run(test)
+    runner.summarize()
+
+testmod('hggit.compat')
+testmod('hggit.hg2git')
+testmod('hggit.util')
+testmod('hggit.git_handler')