1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
// (C) Copyright 2015 Boost.Test team.
// 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)
// See http://www.boost.org/libs/test for the library home page.
//[example_code
#define BOOST_TEST_MODULE example
#include <boost/test/included/unit_test.hpp>
#include <stdexcept>
#include <fstream>
//! Computes the histogram of the words in a text file
class FileWordHistogram
{
public:
//!@throw std::exception if the file does not exist
FileWordHistogram(std::string filename) : is_processed(false), fileStream_(filename) {
if(!fileStream_.is_open()) throw std::runtime_error("Cannot open the file");
}
//! @returns true on success, false otherwise
bool process() {
if(is_processed) return true;
// ...
is_processed = true;
return true;
}
//!@pre process has been called with status success
//!@throw std::logic_error if preconditions not met
std::map<std::string, std::size_t>
result() const {
if(!is_processed)
throw std::runtime_error("\"process\" has not been called or was not successful");
return histogram;
}
private:
bool is_processed;
std::ifstream fileStream_;
std::map<std::string, std::size_t> histogram;
};
BOOST_AUTO_TEST_CASE( test_throw_behaviour )
{
// __FILE__ is accessible, no exception expected
BOOST_REQUIRE_NO_THROW( FileWordHistogram(__FILE__) );
// ".. __FILE__" does not exist, API says std::exception, and implementation
// raises std::runtime_error child of std::exception
BOOST_CHECK_THROW( FileWordHistogram(".." __FILE__), std::exception );
{
FileWordHistogram instance(__FILE__);
// api says "std::logic_error", implementation is wrong.
// std::runtime_error not a child of std::logic_error, not intercepted
// here.
BOOST_CHECK_THROW(instance.result(), std::logic_error);
}
}
//]
|
