external/bsd/lutok/dist/test_utils.hpp

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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
  49 namespace {
  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.
  79 static inline lua_State*
  80 raw(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.
  92 class 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
 102 public:
 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() || _state.to_integer() != 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