Python Unit Testing: Automatically Running the Debugger when a test fails
pdb, python, python-unittest, unit-testing
Solution
import unittest
import sys
import pdb
import functools
import traceback
def debug_on(*exceptions):
if not exceptions:
exceptions = (AssertionError, )
def decorator(f):
@functools.wraps(f)
def wrapper(*args, **kwargs):
try:
return f(*args, **kwargs)
except exceptions:
info = sys.exc_info()
traceback.print_exception(*info)
pdb.post_mortem(info[2])
return wrapper
return decorator
class tests(unittest.TestCase):
@debug_on()
def test_trigger_pdb(self):
assert 1 == 0
I corrected the code to call post_mortem on the exception instead of set_trace.
Problem
Is there a way to automatically start the debugger at the point at which a unittest fails? Right now I am just using pdb.set_trace() manually, but this is very tedious as I need to add it each time and take it out at the end. For Example: ``` import unittest class tests(unittest.TestCase): def setUp(self): pass def test_trigger_pdb(self): #this is the way I do it now try: assert 1==0 except AssertionError: import pdb pdb.set_trace() def test_no_trigger(self): #this is the way I would like to do it: a=1 b=2 assert a==b #magically, pdb would start here #so that I could inspect the values of a and b if __name__=='__main__': #In the documentation the unittest.TestCase has a debug() method #but I don't understand how to use it #A=tests() #A.debug(A) unittest.main() ```