1 // Copyright 2008 Google Inc.
2 // All Rights Reserved.
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5 // modification, are permitted provided that the following conditions are
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11 // copyright notice, this list of conditions and the following disclaimer
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18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 // Author: vladl@google.com (Vlad Losev)
32 // This sample shows how to test code relying on some global flag variables.
33 // Combine() helps with generating all possible combinations of such flags,
34 // and each test is given one combination as a parameter.
36 // Use class definitions to test from this header.
37 #include "prime_tables.h"
39 #include "gtest/gtest.h"
43 // Suppose we want to introduce a new, improved implementation of PrimeTable
44 // which combines speed of PrecalcPrimeTable and versatility of
45 // OnTheFlyPrimeTable (see prime_tables.h). Inside it instantiates both
46 // PrecalcPrimeTable and OnTheFlyPrimeTable and uses the one that is more
47 // appropriate under the circumstances. But in low memory conditions, it can be
48 // told to instantiate without PrecalcPrimeTable instance at all and use only
49 // OnTheFlyPrimeTable.
50 class HybridPrimeTable
: public PrimeTable
{
52 HybridPrimeTable(bool force_on_the_fly
, int max_precalculated
)
53 : on_the_fly_impl_(new OnTheFlyPrimeTable
),
54 precalc_impl_(force_on_the_fly
? NULL
:
55 new PreCalculatedPrimeTable(max_precalculated
)),
56 max_precalculated_(max_precalculated
) {}
57 virtual ~HybridPrimeTable() {
58 delete on_the_fly_impl_
;
62 virtual bool IsPrime(int n
) const {
63 if (precalc_impl_
!= NULL
&& n
< max_precalculated_
)
64 return precalc_impl_
->IsPrime(n
);
66 return on_the_fly_impl_
->IsPrime(n
);
69 virtual int GetNextPrime(int p
) const {
71 if (precalc_impl_
!= NULL
&& p
< max_precalculated_
)
72 next_prime
= precalc_impl_
->GetNextPrime(p
);
74 return next_prime
!= -1 ? next_prime
: on_the_fly_impl_
->GetNextPrime(p
);
78 OnTheFlyPrimeTable
* on_the_fly_impl_
;
79 PreCalculatedPrimeTable
* precalc_impl_
;
80 int max_precalculated_
;
83 using ::testing::TestWithParam
;
84 using ::testing::Bool
;
85 using ::testing::Values
;
86 using ::testing::Combine
;
88 // To test all code paths for HybridPrimeTable we must test it with numbers
89 // both within and outside PreCalculatedPrimeTable's capacity and also with
90 // PreCalculatedPrimeTable disabled. We do this by defining fixture which will
91 // accept different combinations of parameters for instantiating a
92 // HybridPrimeTable instance.
93 class PrimeTableTest
: public TestWithParam
< ::testing::tuple
<bool, int> > {
95 virtual void SetUp() {
96 // This can be written as
98 // bool force_on_the_fly;
99 // int max_precalculated;
100 // tie(force_on_the_fly, max_precalculated) = GetParam();
102 // once the Google C++ Style Guide allows use of ::std::tr1::tie.
104 bool force_on_the_fly
= ::testing::get
<0>(GetParam());
105 int max_precalculated
= ::testing::get
<1>(GetParam());
106 table_
= new HybridPrimeTable(force_on_the_fly
, max_precalculated
);
108 virtual void TearDown() {
112 HybridPrimeTable
* table_
;
115 TEST_P(PrimeTableTest
, ReturnsFalseForNonPrimes
) {
116 // Inside the test body, you can refer to the test parameter by GetParam().
117 // In this case, the test parameter is a PrimeTable interface pointer which
118 // we can use directly.
119 // Please note that you can also save it in the fixture's SetUp() method
120 // or constructor and use saved copy in the tests.
122 EXPECT_FALSE(table_
->IsPrime(-5));
123 EXPECT_FALSE(table_
->IsPrime(0));
124 EXPECT_FALSE(table_
->IsPrime(1));
125 EXPECT_FALSE(table_
->IsPrime(4));
126 EXPECT_FALSE(table_
->IsPrime(6));
127 EXPECT_FALSE(table_
->IsPrime(100));
130 TEST_P(PrimeTableTest
, ReturnsTrueForPrimes
) {
131 EXPECT_TRUE(table_
->IsPrime(2));
132 EXPECT_TRUE(table_
->IsPrime(3));
133 EXPECT_TRUE(table_
->IsPrime(5));
134 EXPECT_TRUE(table_
->IsPrime(7));
135 EXPECT_TRUE(table_
->IsPrime(11));
136 EXPECT_TRUE(table_
->IsPrime(131));
139 TEST_P(PrimeTableTest
, CanGetNextPrime
) {
140 EXPECT_EQ(2, table_
->GetNextPrime(0));
141 EXPECT_EQ(3, table_
->GetNextPrime(2));
142 EXPECT_EQ(5, table_
->GetNextPrime(3));
143 EXPECT_EQ(7, table_
->GetNextPrime(5));
144 EXPECT_EQ(11, table_
->GetNextPrime(7));
145 EXPECT_EQ(131, table_
->GetNextPrime(128));
148 // In order to run value-parameterized tests, you need to instantiate them,
149 // or bind them to a list of values which will be used as test parameters.
150 // You can instantiate them in a different translation module, or even
151 // instantiate them several times.
153 // Here, we instantiate our tests with a list of parameters. We must combine
154 // all variations of the boolean flag suppressing PrecalcPrimeTable and some
155 // meaningful values for tests. We choose a small value (1), and a value that
156 // will put some of the tested numbers beyond the capability of the
157 // PrecalcPrimeTable instance and some inside it (10). Combine will produce all
158 // possible combinations.
159 INSTANTIATE_TEST_CASE_P(MeaningfulTestParameters
,
161 Combine(Bool(), Values(1, 10)));
165 // Google Test may not support Combine() with some compilers. If we
166 // use conditional compilation to compile out all code referring to
167 // the gtest_main library, MSVC linker will not link that library at
168 // all and consequently complain about missing entry point defined in
169 // that library (fatal error LNK1561: entry point must be
170 // defined). This dummy test keeps gtest_main linked in.
171 TEST(DummyTest
, CombineIsNotSupportedOnThisPlatform
) {}
173 #endif // GTEST_HAS_COMBINE