Doctest fails when normal output and exception mixed together?

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Does doctest support that both output and exception mixed together?

One example is:

>>> def foo():
...    print 'hello world!'
>>> foo()
hello world!
>>> def bar():
...     raise Exception()
>>> bar()
Traceback (most recent call last):
    ...
Exception

>>> def foo_bar():
...     foo()
...     bar()
>>> foo_bar()
hello world!
Traceback (most recent call last):
    ...
Exception

I expect all three cases should be successful, but only two of them does, see

$ python -m doctest -v /tmp/1.py
Trying:
    def foo():
       print 'hello world!'
Expecting nothing
ok
Trying:
    foo()
Expecting:
    hello world!
ok
Trying:
    def bar():
        raise Exception()
Expecting nothing
ok
Trying:
    bar()
Expecting:
    Traceback (most recent call last):
        ...
    Exception
ok
Trying:
    def foo_bar():
        foo()
        bar()
Expecting nothing
ok
Trying:
    foo_bar()
Expecting:
    hello world!
    Traceback (most recent call last):
        ...
    Exception
**********************************************************************
File "/tmp/1.py", line 16, in 1
Failed example:
    foo_bar()
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib/python2.7/doctest.py", line 1315, in __run
        compileflags, 1) in test.globs
      File "<doctest 1[5]>", line 1, in <module>
        foo_bar()
      File "<doctest 1[4]>", line 3, in foo_bar
        bar()
      File "<doctest 1[2]>", line 2, in bar
        raise Exception()
    Exception
**********************************************************************
1 items had failures:
   1 of   6 in 1
6 tests in 1 items.
5 passed and 1 failed.
***Test Failed*** 1 failures.
2

There are 2 answers

0
user2357112 On BEST ANSWER

The docs say you can't do that:

Examples containing both expected output and an exception are not supported. Trying to guess where one ends and the other begins is too error-prone, and that also makes for a confusing test.

0
AndiDog On

Regular output and tracebacks cannot be mixed since they are just indistinguishable text. However you can wrap the block, catching the exception you expect:

>>> try:
...     foo_bar()
... except TheSpecificExceptionYouWant:
...     pass
... else:
...     raise AssertionError('Should have raised an exception')
hello world!