1. download:
$ cd /home/maymay/ex/gtest/
$ wget https://github.com/google/googletest/archive/refs/tags/release-1.10.0.tar.gz
$ tar zxf release-1.10.0.tar.gz
$ cd ./googletest-release-1.10.0/
$ pwd
shows: /home/maymay/ex/gtest/googletest-release-1.10.0/
2. compile:
$ mkdir ./build
$ cd ./build/
$ sudo apt-get install build-essential
$ sudo apt install cmake
$ cmake .. -DBUILD_SHARED_LIBS=ON
$ ls ./lib/
shows :
libgmock_main.so libgtest_main.so libgmock.so libgtest.so
3. program any path:
file 1 save as:
prime_tables.h
//prime_tables.h
#ifndef GTEST_SAMPLES_PRIME_TABLES_H_
#define GTEST_SAMPLES_PRIME_TABLES_H_
#include <algorithm>
// The prime table interface.
class PrimeTable {
public:
virtual ~PrimeTable() {}
// Returns true if and only if n is a prime number.
virtual bool IsPrime(int n) const = 0;
// Returns the smallest prime number greater than p; or returns -1
// if the next prime is beyond the capacity of the table.
virtual int GetNextPrime(int p) const = 0;
};
// Implementation #1 calculates the primes on-the-fly.
class OnTheFlyPrimeTable : public PrimeTable {
public:
bool IsPrime(int n) const override {
if (n <= 1) return false;
for (int i = 2; i*i <= n; i++) {
// n is divisible by an integer other than 1 and itself.
if ((n % i) == 0) return false;
}
return true;
}
int GetNextPrime(int p) const override {
for (int n = p + 1; n > 0; n++) {
if (IsPrime(n)) return n;
}
return -1;
}
};
// Implementation #2 pre-calculates the primes and stores the result
// in an array.
class PreCalculatedPrimeTable : public PrimeTable {
public:
// 'max' specifies the maximum number the prime table holds.
explicit PreCalculatedPrimeTable(int max)
: is_prime_size_(max + 1), is_prime_(new bool[max + 1]) {
CalculatePrimesUpTo(max);
}
~PreCalculatedPrimeTable() override { delete[] is_prime_; }
bool IsPrime(int n) const override {
return 0 <= n && n < is_prime_size_ && is_prime_[n];
}
int GetNextPrime(int p) const override {
for (int n = p + 1; n < is_prime_size_; n++) {
if (is_prime_[n]) return n;
}
return -1;
}
private:
void CalculatePrimesUpTo(int max) {
::std::fill(is_prime_, is_prime_ + is_prime_size_, true);
is_prime_[0] = is_prime_[1] = false;
// Checks every candidate for prime number (we know that 2 is the only even
// prime).
for (int i = 2; i*i <= max; i += i%2+1) {
if (!is_prime_[i]) continue;
// Marks all multiples of i (except i itself) as non-prime.
// We are starting here from i-th multiplier, because all smaller
// complex numbers were already marked.
for (int j = i*i; j <= max; j += i) {
is_prime_[j] = false;
}
}
}
const int is_prime_size_;
bool* const is_prime_;
// Disables compiler warning "assignment operator could not be generated."
void operator=(const PreCalculatedPrimeTable& rhs);
};
#endif // GTEST_SAMPLES_PRIME_TABLES_H_
file 2 save as: sample8_unittest.cc
// Copyright 2008 Google Inc.
// All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// This sample shows how to test code relying on some global flag variables.
// Combine() helps with generating all possible combinations of such flags,
// and each test is given one combination as a parameter.
// Use class definitions to test from this header.
#include "prime_tables.h"
#include "gtest/gtest.h"
namespace {
// Suppose we want to introduce a new, improved implementation of PrimeTable
// which combines speed of PrecalcPrimeTable and versatility of
// OnTheFlyPrimeTable (see prime_tables.h). Inside it instantiates both
// PrecalcPrimeTable and OnTheFlyPrimeTable and uses the one that is more
// appropriate under the circumstances. But in low memory conditions, it can be
// told to instantiate without PrecalcPrimeTable instance at all and use only
// OnTheFlyPrimeTable.
class HybridPrimeTable : public PrimeTable {
public:
HybridPrimeTable(bool force_on_the_fly, int max_precalculated)
: on_the_fly_impl_(new OnTheFlyPrimeTable),
precalc_impl_(force_on_the_fly
? nullptr
: new PreCalculatedPrimeTable(max_precalculated)),
max_precalculated_(max_precalculated) {}
~HybridPrimeTable() override {
delete on_the_fly_impl_;
delete precalc_impl_;
}
bool IsPrime(int n) const override {
if (precalc_impl_ != nullptr && n < max_precalculated_)
return precalc_impl_->IsPrime(n);
else
return on_the_fly_impl_->IsPrime(n);
}
int GetNextPrime(int p) const override {
int next_prime = -1;
if (precalc_impl_ != nullptr && p < max_precalculated_)
next_prime = precalc_impl_->GetNextPrime(p);
return next_prime != -1 ? next_prime : on_the_fly_impl_->GetNextPrime(p);
}
private:
OnTheFlyPrimeTable* on_the_fly_impl_;
PreCalculatedPrimeTable* precalc_impl_;
int max_precalculated_;
};
using ::testing::TestWithParam;
using ::testing::Bool;
using ::testing::Values;
using ::testing::Combine;
// To test all code paths for HybridPrimeTable we must test it with numbers
// both within and outside PreCalculatedPrimeTable's capacity and also with
// PreCalculatedPrimeTable disabled. We do this by defining fixture which will
// accept different combinations of parameters for instantiating a
// HybridPrimeTable instance.
class PrimeTableTest : public TestWithParam< ::std::tuple<bool, int> > {
protected:
void SetUp() override {
bool force_on_the_fly;
int max_precalculated;
std::tie(force_on_the_fly, max_precalculated) = GetParam();
table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated);
}
void TearDown() override {
delete table_;
table_ = nullptr;
}
HybridPrimeTable* table_;
};
TEST_P(PrimeTableTest, ReturnsFalseForNonPrimes) {
// Inside the test body, you can refer to the test parameter by GetParam().
// In this case, the test parameter is a PrimeTable interface pointer which
// we can use directly.
// Please note that you can also save it in the fixture's SetUp() method
// or constructor and use saved copy in the tests.
EXPECT_FALSE(table_->IsPrime(-5));
EXPECT_FALSE(table_->IsPrime(0));
EXPECT_FALSE(table_->IsPrime(1));
EXPECT_FALSE(table_->IsPrime(4));
EXPECT_FALSE(table_->IsPrime(6));
EXPECT_FALSE(table_->IsPrime(100));
}
TEST_P(PrimeTableTest, ReturnsTrueForPrimes) {
EXPECT_TRUE(table_->IsPrime(2));
EXPECT_TRUE(table_->IsPrime(3));
EXPECT_TRUE(table_->IsPrime(5));
EXPECT_TRUE(table_->IsPrime(7));
EXPECT_TRUE(table_->IsPrime(11));
EXPECT_TRUE(table_->IsPrime(131));
}
TEST_P(PrimeTableTest, CanGetNextPrime) {
EXPECT_EQ(2, table_->GetNextPrime(0));
EXPECT_EQ(3, table_->GetNextPrime(2));
EXPECT_EQ(5, table_->GetNextPrime(3));
EXPECT_EQ(7, table_->GetNextPrime(5));
EXPECT_EQ(11, table_->GetNextPrime(7));
EXPECT_EQ(131, table_->GetNextPrime(128));
}
// In order to run value-parameterized tests, you need to instantiate them,
// or bind them to a list of values which will be used as test parameters.
// You can instantiate them in a different translation module, or even
// instantiate them several times.
//
// Here, we instantiate our tests with a list of parameters. We must combine
// all variations of the boolean flag suppressing PrecalcPrimeTable and some
// meaningful values for tests. We choose a small value (1), and a value that
// will put some of the tested numbers beyond the capability of the
// PrecalcPrimeTable instance and some inside it (10). Combine will produce all
// possible combinations.
INSTANTIATE_TEST_SUITE_P(MeaningfulTestParameters, PrimeTableTest,
Combine(Bool(), Values(1, 10)));
} // namespace
int main(int argc, char **argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}3. compile:
$ ls ./
shows: prime_tables.h sample8_unittest.cc
$ g++ sample8_unittest.cc -I /home/maymay/ex/gtest/googletest-release-1.10.0/googletest/include/ -L /home/maymay/ex/gtest/googletest-release-1.10.0/build/lib/ -lgtest
$ ls ./
shows: a.out prime_tables.h sample8_unittest.cc
$ ./a.out
if there is no function main() in the source file sample8_unittest.cc, then, should use this compile command:
$ g++ sample8_unittest.cc -I /home/maymay/ex/ex_gtest/ -I /home/maymay/ex/gtest/googletest-release-1.10.0/googletest/include/ -L /home/maymay/ex/gtest/googletest-release-1.10.0/build/lib/ -lgtest_main -lgtest
libgtest_main.so only contains the correct main function.
