test/doc/testing_tools/boost_test_universal_macro.qbk
2015-10-26 21:03:43 +00:00

85 lines
4.5 KiB
Plaintext

[/
/ Copyright (c) 2015 Boost.Test contributors
/
/ Distributed under the Boost Software License, Version 1.0. (See accompanying
/ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
/]
[section:boost_test_universal_macro BOOST_TEST: universal and general purpose assertions]
The __UTF__ provides an almost unique interface to a great range of test-case scenarios, through the __BOOST_TEST__
macro. The general form of `BOOST_TEST` is the following:
BOOST_TEST(statement);
BOOST_TEST_<level>(statement, optional_modifiers)
An example of use might be the following:
[bt_example boost_test_macro_overview..BOOST_TEST overview..run-fail]
The major features of this tool are:
* a great flexibility for `statement` which may be almost anything: full expression composed by several operations are supported
and handled,
* an extended reporting capability in case of failure: not only `BOOST_TEST` reports the location of the failure and a copy of `statement` itself,
but also the values of the operands that permits a rapid identification of the issues related to the failed assertion,
* the possibility to control better the behavior or the reports of the checks, in particular:
* floating point comparison: the tolerance may be provided, either using the `BOOST_TEST`
directly with `optional_modifiers`, or with /decorators/ (see [link boost_test.testing_tools.extended_comparison.floating_point here]
for more details),
* container/collection comparisons: different operations for comparison are provided out of the box for comparing collection of
elements (default, per-element, lexicographic), with extended diagnostic on failures (covered in
[link boost_test.testing_tools.extended_comparison.collections this] section),
* string comparison: C-strings operands are automatically detected and the comparisons are performed as if `std::string` objects
were used,
* optional failure message,
* bitwise comparison, providing extended diagnostic in case of failure
[warning To get all the functionalities of `BOOST_TEST` family of assertions, a C++11 capable compiler is required, especially
supporting the `auto` and `decltype` keywords and the variadic macros. The documentation focuses on these set of compilers.
For compilers not supporting all the features of `BOOST_TEST`, the macro `BOOST_TEST_MACRO_LIMITED_SUPPORT`.]
[#boost_test_statement_overloads][h3 Complex statements]
`BOOST_TEST` provides an enhanced reporting capability: additional details of the failing operands and operations are provided in the log,
as shown on the example below:
[bt_example boost_test_macro3..BOOST_TEST enhanced reporting..run-fail]
`BOOST_TEST` parses the `statement` and constructs an expression out of it. `statement` may be a complex expressions
containing almost any of the overloadable operators in C++:
[table
[[Class of operation][operators]]
[[binary comparisons][`==`, `!=`, `<`, `>`, `<=`, `>=`]]
[[arithmetic compositions][`+`, `-`, `*`, `/`, `%`]]
[[bitwise compositions][`|`, `&`, `^`, `<<`, `>>`]]
[[assignments][`=`, `+=`, `-=`, `*=`, `/=`, `%=`, `<<=`, `>>=`, `&=`, `^=`, `|=`]]
]
`statement` is evaluated and cast to `bool`, as if it would appear as argument to an `if` statement: this is the result of the assertion
[h3 Uniform reporting]
This tool is provided in three variants corresponding to the corresponding
[link boost_test.testing_tools.tools_assertion_severity_level severity levels]. These three levels of assertions are
reported into the test log and output, as described in details in the section. The granularity of the
report depends on the current [link boost_test.utf_reference.rt_param_reference.log_level log level] and
[link boost_test.utf_reference.rt_param_reference.report_level report level].
[#boost_test_statement_limitations][h3 Limitations & workaround]
There are a few constructions that are however unsupported, but adding an extra bracket usually solves that:
* statements containing ternary conditions: those statement should be surrounded by parenthesis as they cannot be overloaded
* statements containing commas: those statements will be intercepted by the preprocessor
* compound statements containing any logical composition `||`, `&&`. Those are disabled intentionally and should be surrounded
by parenthesis
BOOST_TEST((true || false));
The full details are given in [link boost_test.testing_tools.internal_details this section].
[bt_example boost_test_macro_workaround..BOOST_TEST limitation and workaround..run]
[endsect] [/ boost_test_universal_macro]