Files
nearby/cpp/platform/base/prng_test.cc
T
Alexey Polyudov 2155b3ddeb Roll forward to cl/338482889
Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: I9850950db8bd84f0904ea1a413151887f52098cf
2020-10-22 10:47:34 -07:00

78 lines
1.9 KiB
C++

#include "platform/base/prng.h"
#include "gtest/gtest.h"
namespace location {
namespace nearby {
enum class TestMode {
kUpperHalfOfInt64,
kLowerHalfOfInt64,
kInt32,
kUint32,
};
TEST(PrngTest, NextInt32) {
std::int32_t i = Prng().NextInt32();
EXPECT_LE(i, std::numeric_limits<std::int32_t>::max());
EXPECT_GE(i, std::numeric_limits<std::int32_t>::min());
}
TEST(PrngTest, NextUInt32) {
std::uint32_t i = Prng().NextUint32();
EXPECT_LE(i, std::numeric_limits<std::uint32_t>::max());
EXPECT_GE(i, std::numeric_limits<std::uint32_t>::min());
}
TEST(PrngTest, NextInt64) {
std::int64_t i = Prng().NextInt64();
EXPECT_LE(i, std::numeric_limits<std::int64_t>::max());
EXPECT_GE(i, std::numeric_limits<std::int64_t>::min());
}
void ValidateRandom(TestMode mode) {
int count_all_zeros = 0;
int count_all_ones = 0;
std::uint32_t i;
Prng prng;
for (int count = 0; count < 100; ++count) {
switch (mode) {
case TestMode::kUpperHalfOfInt64:
i = static_cast<std::uint32_t>(prng.NextInt64() >> 32);
break;
case TestMode::kLowerHalfOfInt64:
i = static_cast<std::uint32_t>(prng.NextInt64());
break;
case TestMode::kInt32:
i = static_cast<std::uint32_t>(prng.NextInt32());
break;
case TestMode::kUint32:
i = static_cast<std::uint32_t>(prng.NextUint32());
break;
}
if (!i) count_all_zeros++;
if (i == 0xFFFFFFFF) count_all_ones++;
}
EXPECT_LE(count_all_zeros, 1);
EXPECT_LE(count_all_ones, 1);
}
TEST(PrngTest, ValidateUpperHalfOfInt64) {
ValidateRandom(TestMode::kUpperHalfOfInt64);
}
TEST(PrngTest, ValidateLowerHalfOfInt64) {
ValidateRandom(TestMode::kLowerHalfOfInt64);
}
TEST(PrngTest, ValidateInt32) {
ValidateRandom(TestMode::kInt32);
}
TEST(PrngTest, ValidateUint32) {
ValidateRandom(TestMode::kUint32);
}
} // namespace nearby
} // namespace location