catch2/tests/SelfTest/IntrospectiveTests/RandomNumberGeneration.tests.cpp
2021-10-08 21:35:41 +02:00

60 lines
2.0 KiB
C++

/*
* 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)
*/
#include <catch2/catch_test_macros.hpp>
#include <catch2/internal/catch_random_number_generator.hpp>
#include <catch2/internal/catch_random_seed_generation.hpp>
#include <catch2/generators/catch_generators.hpp>
TEST_CASE("Our PCG implementation provides expected results for known seeds", "[rng]") {
Catch::SimplePcg32 rng;
SECTION("Default seeded") {
REQUIRE(rng() == 0xfcdb943b);
REQUIRE(rng() == 0x6f55b921);
REQUIRE(rng() == 0x4c17a916);
REQUIRE(rng() == 0x71eae25f);
REQUIRE(rng() == 0x6ce7909c);
}
SECTION("Specific seed") {
rng.seed(0xabcd1234);
REQUIRE(rng() == 0x57c08495);
REQUIRE(rng() == 0x33c956ac);
REQUIRE(rng() == 0x2206fd76);
REQUIRE(rng() == 0x3501a35b);
REQUIRE(rng() == 0xfdffb30f);
// Also check repeated output after reseeding
rng.seed(0xabcd1234);
REQUIRE(rng() == 0x57c08495);
REQUIRE(rng() == 0x33c956ac);
REQUIRE(rng() == 0x2206fd76);
REQUIRE(rng() == 0x3501a35b);
REQUIRE(rng() == 0xfdffb30f);
}
}
TEST_CASE("Comparison ops", "[rng]") {
using Catch::SimplePcg32;
REQUIRE(SimplePcg32{} == SimplePcg32{});
REQUIRE(SimplePcg32{ 0 } != SimplePcg32{});
REQUIRE_FALSE(SimplePcg32{ 1 } == SimplePcg32{ 2 });
REQUIRE_FALSE(SimplePcg32{ 1 } != SimplePcg32{ 1 });
}
TEST_CASE("Random seed generation reports unknown methods", "[rng][seed]") {
REQUIRE_THROWS(Catch::generateRandomSeed(static_cast<Catch::GenerateFrom>(77)));
}
TEST_CASE("Random seed generation accepts known methods", "[rng][seed]") {
using Catch::GenerateFrom;
const auto method = GENERATE(
GenerateFrom::Time,
GenerateFrom::RandomDevice,
GenerateFrom::Default
);
REQUIRE_NOTHROW(Catch::generateRandomSeed(method));
}