Automatic TestCase creation for rst literal_block shell examples in python class docstrings

rst_parse.py

import sys
import unittest
from docutils.core import publish_doctree
import subprocess
import opendir_dl

class ShellTestCase(unittest.TestCase):
    def assert_shell_yields(self, command, expected_result):
        result = subprocess.check_output(command, shell=True)[:-1]
        if result != expected_result:
            raise ValueError

def test_case_factory(command, result):
    def test_shell_result(self):
        self.assert_shell_yields(command, result)
    return test_shell_result

def shell_factory(cls, name):
    shell_test_case = type(cls.__name__, (ShellTestCase,), dict(ShellTestCase.__dict__))
    method_counter = 0
    for i in get_code_blocks(cls.__doc__):
        func = test_case_factory(i['command'], i['result'])
        setattr(shell_test_case, "test_{}".format(method_counter), func)
        method_counter += 1
    return shell_test_case

def get_code_blocks(source_text):
    return_list = []
    if not source_text:
        return return_list
    doctree = publish_doctree(source_text)
    for child in doctree.children:
        if child.tagname == "literal_block":
            code_block = {}
            code_lines = child.astext().split("\n")
            # Parse execution line
            code_block['command'] = code_lines[0][1:].strip()
            # Parse execution result
            code_block['result'] = str("\n".join(code_lines[1:]))
            # Append to return list
            return_list.append(code_block)
    return return_list

class_list = [
    opendir_dl.commands.tag_list_command,
    opendir_dl.commands.TagCreateCommand,
    opendir_dl.commands.TagDeleteCommand
]

thismodule = sys.modules[__name__]

for i in class_list:
    shell_test_case = shell_factory(i, i.__name__)
    setattr(thismodule, shell_test_case.__name__, shell_test_case)

# Example usage (note the names of classes from opendir_dl.commands are a little messy at the moment)
#
#>>> import unittest
#>>> import rst_parse
#>>> suite1 = unittest.TestLoader().loadTestsFromTestCase(rst_parse.tag_list_command)
#>>> suite2 = unittest.TestLoader().loadTestsFromTestCase(rst_parse.TagCreateCommand)
#>>> test_suite = unittest.TestSuite([suite, suite2])
#>>> unittest.TextTestRunner(verbosity=2).run(test_suite)
#test_0 (rst_parse.tag_list_command) ... ok
#test_0 (rst_parse.TagCreateCommand) ... Usage:
#test_0 (rst_parse.TagCreateCommand) ... Usage:
#        opendir-dl help [options]
#        <LONG OUTPUT REMOVED>
#        opendir-dl database delete [options] <name>...
#ERROR
#
#======================================================================
#ERROR: test_0 (rst_parse.TagCreateCommand)
#----------------------------------------------------------------------
#Traceback (most recent call last):
#  File "rst_parse.py", line 17, in test_shell_result
#    self.assert_shell_yields(command, result)
#  File "rst_parse.py", line 11, in assert_shell_yields
#    result = subprocess.check_output(command, shell=True)[:-1]
#  File "/usr/lib/python2.7/subprocess.py", line 574, in check_output
#    raise CalledProcessError(retcode, cmd, output=output)
#CalledProcessError: Command 'opendir-dl create testing_command' returned non-zero exit status 1
#
#----------------------------------------------------------------------
#Ran 2 tests in 0.463s
#
#FAILED (errors=1)
#<unittest.runner.TextTestResult run=2 errors=1 failures=0>