Expect a value within a given range using Google Test - c++

Question

I want to specify an expectation that a value is between an upper and lower bound, inclusively.
Google Test provides LT,LE,GT,GE, but no way of testing a range that I can see. You could use EXPECT_NEAR and juggle the operands, but in many cases this isn't as clear as explicitly setting upper and lower bounds.
Usage should resemble:
EXPECT_WITHIN_INCLUSIVE(1, 3, 2); // 2 is in range [1,3]
How would one add this expectation?

Answer 1

Google mock has richer composable matchers:
EXPECT_THAT(x, AllOf(Ge(1),Le(3)));
Maybe that would work for you.

Answer 2

Using just Google Test (not mock), then the simple, obvious answer is:
EXPECT_TRUE((a >= 1) && (a <= 3)); // a is between 1 and 3 inclusive
I find this more readable than some of the Mock based answers.
--- begin edit --
The simple answer above not providing any useful diagnostics
You can use AssertionResult to define a custom assert that does produce useful a useful error message like this.
#include <gtest/gtest.h>
::testing::AssertionResult IsBetweenInclusive(int val, int a, int b)
{
if((val >= a) && (val <= b))
return ::testing::AssertionSuccess();
else
return ::testing::AssertionFailure()
<< val << " is outside the range " << a << " to " << b;
}
TEST(testing, TestPass)
{
auto a = 2;
EXPECT_TRUE(IsBetweenInclusive(a, 1, 3));
}
TEST(testing, TestFail)
{
auto a = 5;
EXPECT_TRUE(IsBetweenInclusive(a, 1, 3));
}

Answer 3

There is a nice example in google mock cheat sheet:
using namespace testing;
MATCHER_P2(IsBetween, a, b,
std::string(negation ? "isn't" : "is") + " between " + PrintToString(a)
+ " and " + PrintToString(b))
{
return a <= arg && arg <= b;
}
Then to use it:
TEST(MyTest, Name) {
EXPECT_THAT(42, IsBetween(40, 46));
}

Answer 4

I would define these macros:
#define EXPECT_IN_RANGE(VAL, MIN, MAX) \
EXPECT_GE((VAL), (MIN)); \
EXPECT_LE((VAL), (MAX))
#define ASSERT_IN_RANGE(VAL, MIN, MAX) \
ASSERT_GE((VAL), (MIN)); \
ASSERT_LE((VAL), (MAX))

Answer 5

In the end I created a macro to do this that resembles other macros in the Google Test lib.
#define EXPECT_WITHIN_INCLUSIVE(lower, upper, val) \
do { \
EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val, lower); \
EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val, upper); \
} while (0)

Answer 6

Using an Existing Boolean Function in Google Test which don't need google mock.The link is quite specific.
Here is the example.
// Returns true iff m and n have no common divisors except 1.
bool MutuallyPrime(int m, int n) { ... }
const int a = 3;
const int b = 4;
const int c = 10;
the assertion EXPECT_PRED2(MutuallyPrime, a, b); will succeed, while
the assertion EXPECT_PRED2(MutuallyPrime, b, c); will fail with the
message
!MutuallyPrime(b, c) is false, where
b is 4
c is 10