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28
29/// \file test_utils.hpp
30/// Utilities for tests of the lua modules.
31///
32/// This file is intended to be included once, and only once, for every test
33/// program that needs it.  All the code is herein contained to simplify the
34/// dependency chain in the build rules.
35
36#if !defined(LUTOK_TEST_UTILS_HPP)
37#   define LUTOK_TEST_UTILS_HPP
38#else
39#   error "test_utils.hpp can only be included once"
40#endif
41
42#include <atf-c++.hpp>
43
44#include "c_gate.hpp"
45#include "exceptions.hpp"
46#include "state.hpp"
47
48
49namespace {
50
51
52/// Checks that a given expression raises a particular lutok::api_error.
53///
54/// We cannot make any assumptions regarding the error text provided by Lua, so
55/// we resort to checking only which API function raised the error (because our
56/// code is the one hardcoding these strings).
57///
58/// \param exp_api_function The name of the Lua C API function that causes the
59///     error.
60/// \param statement The statement to execute.
61#define REQUIRE_API_ERROR(exp_api_function, statement) \
62    do { \
63        try { \
64            statement; \
65            ATF_FAIL("api_error not raised by " #statement); \
66        } catch (const lutok::api_error& api_error) { \
67            ATF_REQUIRE_EQ(exp_api_function, api_error.api_function()); \
68        } \
69    } while (0)
70
71
72/// Gets the pointer to the internal lua_State of a state object.
73///
74/// This is pure syntactic sugar to simplify typing in the test cases.
75///
76/// \param state The Lua state.
77///
78/// \return The internal lua_State of the input Lua state.
79static inline lua_State*
80raw(lutok::state& state)
81{
82    return lutok::state_c_gate(state).c_state();
83}
84
85
86/// Ensures that the Lua stack maintains its original height upon exit.
87///
88/// Use an instance of this class to check that a piece of code does not have
89/// side-effects on the Lua stack.
90///
91/// To be used within a test case only.
92class stack_balance_checker {
93    /// The Lua state.
94    lutok::state& _state;
95
96    /// Whether to install a sentinel on the stack for balance enforcement.
97    bool _with_sentinel;
98
99    /// The height of the stack on creation.
100    unsigned int _old_count;
101
102public:
103    /// Constructs a new stack balance checker.
104    ///
105    /// \param state_ The Lua state to validate.
106    /// \param with_sentinel_ If true, insert a sentinel item into the stack and
107    ///     validate upon exit that the item is still there.  This is an attempt
108    ///     to ensure that already-existing items are not removed from the stack
109    ///     by the code under test.
110    stack_balance_checker(lutok::state& state_,
111                          const bool with_sentinel_ = true) :
112        _state(state_),
113        _with_sentinel(with_sentinel_),
114        _old_count(_state.get_top())
115    {
116        if (_with_sentinel)
117            _state.push_integer(987654321);
118    }
119
120    /// Destructor for the object.
121    ///
122    /// If the stack height does not match the height when the instance was
123    /// created, this fails the test case.
124    ~stack_balance_checker(void)
125    {
126        if (_with_sentinel) {
127            if (!_state.is_number(-1) || _state.to_integer(-1) != 987654321)
128                ATF_FAIL("Stack corrupted: sentinel not found");
129            _state.pop(1);
130        }
131
132        unsigned int new_count = _state.get_top();
133        if (_old_count != new_count)
134            //ATF_FAIL(F("Stack not balanced: before %d, after %d") %
135            //         _old_count % new_count);
136            ATF_FAIL("Stack not balanced");
137    }
138};
139
140
141}  // anonymous namespace
142