I guess the main reason for assert not being used more often is that nobody uses Python’s “optimized” mode. Asserts are a great tool to detect programming mistakes, to guard yourself from unexpected situations, but all this error checking comes with a cost. In compiled languages such as C/C++, this does not really matter, since … Read more
Assert won’t work in Android because most of the time a person isn’t running in debug mode, but rather some optimized code. Thus, the proper solution is to manually throw an exception, with code like this: if (obj==null) throw new AssertionError(“Object cannot be null”); It should be noted that by design, Asserts are intended for … Read more
It means that AreSame() checks that they are the exact same object – if reference indicate the same object in memory. AreEqual() checks that objects has equal type and value. Equal objects can exist in two different places in memory.
http://apigen.juzna.cz/doc/sebastianbergmann/phpunit/function-assertInstanceOf.html I think you are using this function wrong. Try: $this->assertInstanceOf(‘User’, $user);
You certainly can: assert x > 0 : “x must be greater than zero, but x = ” + x; See Programming with Assertions for more information.
The statement assert can be used for checking conditions at runtime, but is removed if optimizations are requested from Python. The extended form is: assert condition, message and is equivalent to: if __debug__: if not condition: raise AssertionError(message) where __debug__ is True is Python was not started with the option -O. So the statement assert … Read more
No it’s not a best practice. The best analogy to assert() in Ruby is just raising raise “This is wrong” unless expr and you can implement your own exceptions if you want to provide for more specific exception handling
Use the traceback module: import sys import traceback try: assert True assert 7 == 7 assert 1 == 2 # many more statements like this except AssertionError: _, _, tb = sys.exc_info() traceback.print_tb(tb) # Fixed format tb_info = traceback.extract_tb(tb) filename, line, func, text = tb_info[-1] print(‘An error occurred on line {} in statement {}’.format(line, text)) … Read more
See the Embedded VM Control document (raw HTML from the source tree, or a nicely formatted copy). Basically, the Dalvik VM is set to ignore assertion checks by default, even though the .dex byte code includes the code to perform the check. Checking assertions is turned on in one of two ways: (1) by setting … Read more
The rule of thumb which is applicable across most languages (all that I vaguely know) is that an assert is used to assert that a condition is always true whereas an if is appropriate if it is conceivable that it will sometimes fail. In this case, I would say that assert is appropriate (based on … Read more