Robot Framework 代码34之 utils\asserts.py

"""Convenience functions for testing both in unit and higher levels.

Benefits:
  - Integrates 100% with unittest (see example below)
  - Can be easily used without unittest (using unittest.TestCase when you
    only need convenient asserts is not so nice)
  - Saved typing and shorter lines because no need to have 'self.' before
    asserts. These are static functions after all so that is OK.
  - All 'equals' methods (by default) report given values even if optional
    message given. This behavior can be controlled with the optional values
    argument.
    
Drawbacks:
  - unittest is not able to filter as much non-interesting traceback away
    as with its own methods because AssertionErrors occur outside


Most of the functions are copied more or less directly from unittest.TestCase
which comes with the following license. Further information about unittest in
general can be found from This module can be
used freely in same terms as unittest.


----[unittest licence]------------------------------------------------

Copyright (c) 1999-2003 Steve Purcell
This module is free software, and you may redistribute it and/or modify
it under the same terms as Python itself, so long as this copyright message
and disclaimer are retained in their original form.

IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF
THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.

THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE.  THE CODE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS,
AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.


----[example usage]---------------------------------------------------

import unittest
from robot.util.asserts import *

class MyTests(unittest.TestCase):
   
    def test_old_style(self):
        self.assertEquals(1, 2, 'my msg')
       
    def test_new_style(self):
        assert_equals(1, 2, 'my msg')


----[example output]--------------------------------------------------

FF
======================================================================
FAIL: test_old_style (__main__.MyTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "example.py", line 7, in test_old_style
    self.assertEquals(1, 2, 'my msg')
AssertionError: my msg

======================================================================
FAIL: test_new_style (__main__.MyTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "example.py", line 10, in test_new_style
    assert_equals(1, 2, 'my msg')
  File "/path/to/robot/asserts.py", line 142, in fail_unless_equal
    _report_unequality_failure(first, second, msg, values, '!=')
  File "/path/to/robot/src/robot/asserts.py", line 209, in _report_unequality_failure
    raise _report_failure(msg)
  File "/path/to/robot/src/robot/asserts.py", line 200, in _report_failure
    raise AssertionError(msg)
AssertionError: my msg: 1 != 2

----------------------------------------------------------------------
Ran 2 tests in 0.000s

FAILED (failures=2)
"""

def fail(msg=None):
    """Fail test immediately with the given message."""
    _report_failure(msg)
   
def error(msg=None):
    """Error test immediately with the given message."""
    _report_error(msg)

def fail_if(expr, msg=None):
    """Fail the test if the expression is True."""
    if expr: _report_failure(msg)

def fail_unless(expr, msg=None):
    """Fail the test unless the expression is True."""
    if not expr: _report_failure(msg)
   
def fail_if_none(obj, msg=None, values=True):
    """Fail the test if given object is None."""
    _msg = 'is None'
    if obj is None:
        if msg is None:
            msg = _msg
        elif values is True:
            msg = '%s: %s' % (msg, _msg)
        _report_failure(msg)
   
def fail_unless_none(obj, msg=None, values=True):
    """Fail the test if given object is not None."""
    _msg = '%r is not None' % obj
    if obj is not None:
        if msg is None:
            msg = _msg
        elif values is True:
            msg = '%s: %s' % (msg, _msg)
        _report_failure(msg)

def fail_unless_raises(exc_class, callable_obj, *args, **kwargs):
    """Fail unless an exception of class exc_class is thrown by callable_obj.

    callable_obj is invoked with arguments args and keyword arguments
    kwargs. If a different type of exception is thrown, it will not be
    caught, and the test case will be deemed to have suffered an
    error, exactly as for an unexpected exception.
    """
    try:
        callable_obj(*args, **kwargs)
    except exc_class:
        return
    else:
        if hasattr(exc_class,'__name__'):
            exc_name = exc_class.__name__
        else:
            exc_name = str(exc_class)
        _report_failure('%s not raised' % exc_name)

def fail_unless_raises_with_msg(exc_class, expected_msg, callable_obj, *args,
                                **kwargs):
    """Similar to fail_unless_raises but also checks the exception message."""
    try:
        callable_obj(*args, **kwargs)
    except exc_class, err:
        assert_equal(expected_msg, str(err), 'Correct exception but wrong message')
    else:
        if hasattr(exc_class,'__name__'):
            exc_name = exc_class.__name__
        else:
            exc_name = str(exc_class)
        _report_failure('%s not raised' % exc_name)


def fail_unless_equal(first, second, msg=None, values=True):
    """Fail if given objects are unequal as determined by the '==' operator."""
    if not first == second:
        _report_unequality_failure(first, second, msg, values, '!=')

def fail_if_equal(first, second, msg=None, values=True):
    """Fail if given objects are equal as determined by the '==' operator."""
    if first == second:
        _report_unequality_failure(first, second, msg, values, '==')

def fail_unless_almost_equal(first, second, places=7, msg=None, values=True):
    """Fail if the two objects are unequal after rounded to given places.

    Unequality is determined by object's difference rounded to the
    given number of decimal places (default 7) and comparing to zero.
    Note that decimal places (from zero) are usually not the same as
    significant digits (measured from the most signficant digit).
    """
    if round(second - first, places) != 0:
        extra = 'within %r places' % places
        _report_unequality_failure(first, second, msg, values, '!=', extra)

def fail_if_almost_equal(first, second, places=7, msg=None, values=True):
    """Fail if the two objects are unequal after rounded to given places.

    Equality is determined by object's difference rounded to to the
    given number of decimal places (default 7) and comparing to zero.
    Note that decimal places (from zero) are usually not the same as
    significant digits (measured from the most signficant digit).
    """
    if round(second-first, places) == 0:
        extra = 'within %r places' % places
        _report_unequality_failure(first, second, msg, values, '==', extra)

# Synonyms for assertion methods

assert_equal = assert_equals = fail_unless_equal
assert_not_equal = assert_not_equals = fail_if_equal
assert_almost_equal = assert_almost_equals = fail_unless_almost_equal
assert_not_almost_equal = assert_not_almost_equals = fail_if_almost_equal
assert_raises = fail_unless_raises
assert_raises_with_msg = fail_unless_raises_with_msg
assert_ = assert_true = fail_unless
assert_false = fail_if
assert_none = fail_unless_none
assert_not_none = fail_if_none

# Helpers

def _report_failure(msg):
    if msg is None:
        raise AssertionError()
    raise AssertionError(msg)

def _report_error(msg):
    if msg is None:
        raise Exception()
    raise Exception(msg)

def _report_unequality_failure(obj1, obj2, msg, values, delim, extra=None):
    if msg is None:
        msg = '%s %s %s' % (obj1, delim, obj2)
    elif values is True:
        msg = '%s: %s %s %s' % (msg, obj1, delim, obj2)
    if values is True and extra is not None:
        msg += ' ' + extra
    _report_failure(msg)
 
文件路径：robotframework-2.1.2\src\robot\utils\asserts.py
功能：断言，等按流程跟踪时再切入。