diff --git a/Doc/library/doctest.rst b/Doc/library/doctest.rst --- a/Doc/library/doctest.rst +++ b/Doc/library/doctest.rst @@ -633,6 +633,14 @@ the output is suppressed. +.. data:: FAIL_FAST + + When specified, exit after the first failing example and don't attempt to run + the remaining examples. Thus, the number of failures reported will always be 1. + This flag may be useful during debugging, since examples after the first + failure won't even produce debugging output. + + .. data:: REPORTING_FLAGS A bitmask or'ing together all the reporting flags above. diff --git a/Lib/doctest.py b/Lib/doctest.py --- a/Lib/doctest.py +++ b/Lib/doctest.py @@ -62,6 +62,7 @@ 'REPORT_NDIFF', 'REPORT_ONLY_FIRST_FAILURE', 'REPORTING_FLAGS', + 'FAIL_FAST', # 1. Utility Functions # 2. Example & DocTest 'Example', @@ -150,11 +151,13 @@ REPORT_CDIFF = register_optionflag('REPORT_CDIFF') REPORT_NDIFF = register_optionflag('REPORT_NDIFF') REPORT_ONLY_FIRST_FAILURE = register_optionflag('REPORT_ONLY_FIRST_FAILURE') +FAIL_FAST = register_optionflag('FAIL_FAST') REPORTING_FLAGS = (REPORT_UDIFF | REPORT_CDIFF | REPORT_NDIFF | - REPORT_ONLY_FIRST_FAILURE) + REPORT_ONLY_FIRST_FAILURE | + FAIL_FAST) # Special string markers for use in `want` strings: BLANKLINE_MARKER = '' @@ -1342,6 +1345,9 @@ else: assert False, ("unknown outcome", outcome) + if failures and self.optionflags & FAIL_FAST: + break + # Restore the option flags (in case they were modified) self.optionflags = original_optionflags diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py --- a/Lib/test/test_doctest.py +++ b/Lib/test/test_doctest.py @@ -1409,8 +1409,40 @@ 2 TestResults(failed=3, attempted=5) -For the purposes of REPORT_ONLY_FIRST_FAILURE, unexpected exceptions -count as failures: +The FAIL_FAST flag causes the runner to exit after the first failing example, +so subsequent examples are not even attempted: + + >>> flags = doctest.FAIL_FAST + >>> doctest.DocTestRunner(verbose=False, optionflags=flags).run(test) + ... # doctest: +ELLIPSIS + ********************************************************************** + File ..., line 5, in f + Failed example: + print(2) # first failure + Expected: + 200 + Got: + 2 + TestResults(failed=1, attempted=2) + +Specifying both FAIL_FAST and REPORT_ONLY_FIRST_FAILURE is equivalent to +FAIL_FAST only: + + >>> flags = doctest.FAIL_FAST | doctest.REPORT_ONLY_FIRST_FAILURE + >>> doctest.DocTestRunner(verbose=False, optionflags=flags).run(test) + ... # doctest: +ELLIPSIS + ********************************************************************** + File ..., line 5, in f + Failed example: + print(2) # first failure + Expected: + 200 + Got: + 2 + TestResults(failed=1, attempted=2) + +For the purposes of both REPORT_ONLY_FIRST_FAILURE and FAIL_FAST, unexpected +exceptions count as failures: >>> def f(x): ... r''' @@ -1437,6 +1469,17 @@ ... ValueError: 2 TestResults(failed=3, attempted=5) + >>> flags = doctest.FAIL_FAST + >>> doctest.DocTestRunner(verbose=False, optionflags=flags).run(test) + ... # doctest: +ELLIPSIS + ********************************************************************** + File ..., line 5, in f + Failed example: + raise ValueError(2) # first failure + Exception raised: + ... + ValueError: 2 + TestResults(failed=1, attempted=2) New option flags can also be registered, via register_optionflag(). Here we reach into doctest's internals a bit.