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Diffstat (limited to 'googlemock/include/gmock/gmock-matchers.h')
| -rw-r--r-- | googlemock/include/gmock/gmock-matchers.h | 240 |
1 files changed, 239 insertions, 1 deletions
diff --git a/googlemock/include/gmock/gmock-matchers.h b/googlemock/include/gmock/gmock-matchers.h index f1805db..2221121 100644 --- a/googlemock/include/gmock/gmock-matchers.h +++ b/googlemock/include/gmock/gmock-matchers.h @@ -30,7 +30,220 @@ // Google Mock - a framework for writing C++ mock classes. // -// This file implements some commonly used argument matchers. More +// The MATCHER* family of macros can be used in a namespace scope to +// define custom matchers easily. +// +// Basic Usage +// =========== +// +// The syntax +// +// MATCHER(name, description_string) { statements; } +// +// defines a matcher with the given name that executes the statements, +// which must return a bool to indicate if the match succeeds. Inside +// the statements, you can refer to the value being matched by 'arg', +// and refer to its type by 'arg_type'. +// +// The description string documents what the matcher does, and is used +// to generate the failure message when the match fails. Since a +// MATCHER() is usually defined in a header file shared by multiple +// C++ source files, we require the description to be a C-string +// literal to avoid possible side effects. It can be empty, in which +// case we'll use the sequence of words in the matcher name as the +// description. +// +// For example: +// +// MATCHER(IsEven, "") { return (arg % 2) == 0; } +// +// allows you to write +// +// // Expects mock_foo.Bar(n) to be called where n is even. +// EXPECT_CALL(mock_foo, Bar(IsEven())); +// +// or, +// +// // Verifies that the value of some_expression is even. +// EXPECT_THAT(some_expression, IsEven()); +// +// If the above assertion fails, it will print something like: +// +// Value of: some_expression +// Expected: is even +// Actual: 7 +// +// where the description "is even" is automatically calculated from the +// matcher name IsEven. +// +// Argument Type +// ============= +// +// Note that the type of the value being matched (arg_type) is +// determined by the context in which you use the matcher and is +// supplied to you by the compiler, so you don't need to worry about +// declaring it (nor can you). This allows the matcher to be +// polymorphic. For example, IsEven() can be used to match any type +// where the value of "(arg % 2) == 0" can be implicitly converted to +// a bool. In the "Bar(IsEven())" example above, if method Bar() +// takes an int, 'arg_type' will be int; if it takes an unsigned long, +// 'arg_type' will be unsigned long; and so on. +// +// Parameterizing Matchers +// ======================= +// +// Sometimes you'll want to parameterize the matcher. For that you +// can use another macro: +// +// MATCHER_P(name, param_name, description_string) { statements; } +// +// For example: +// +// MATCHER_P(HasAbsoluteValue, value, "") { return abs(arg) == value; } +// +// will allow you to write: +// +// EXPECT_THAT(Blah("a"), HasAbsoluteValue(n)); +// +// which may lead to this message (assuming n is 10): +// +// Value of: Blah("a") +// Expected: has absolute value 10 +// Actual: -9 +// +// Note that both the matcher description and its parameter are +// printed, making the message human-friendly. +// +// In the matcher definition body, you can write 'foo_type' to +// reference the type of a parameter named 'foo'. For example, in the +// body of MATCHER_P(HasAbsoluteValue, value) above, you can write +// 'value_type' to refer to the type of 'value'. +// +// We also provide MATCHER_P2, MATCHER_P3, ..., up to MATCHER_P$n to +// support multi-parameter matchers. +// +// Describing Parameterized Matchers +// ================================= +// +// The last argument to MATCHER*() is a string-typed expression. The +// expression can reference all of the matcher's parameters and a +// special bool-typed variable named 'negation'. When 'negation' is +// false, the expression should evaluate to the matcher's description; +// otherwise it should evaluate to the description of the negation of +// the matcher. For example, +// +// using testing::PrintToString; +// +// MATCHER_P2(InClosedRange, low, hi, +// std::string(negation ? "is not" : "is") + " in range [" + +// PrintToString(low) + ", " + PrintToString(hi) + "]") { +// return low <= arg && arg <= hi; +// } +// ... +// EXPECT_THAT(3, InClosedRange(4, 6)); +// EXPECT_THAT(3, Not(InClosedRange(2, 4))); +// +// would generate two failures that contain the text: +// +// Expected: is in range [4, 6] +// ... +// Expected: is not in range [2, 4] +// +// If you specify "" as the description, the failure message will +// contain the sequence of words in the matcher name followed by the +// parameter values printed as a tuple. For example, +// +// MATCHER_P2(InClosedRange, low, hi, "") { ... } +// ... +// EXPECT_THAT(3, InClosedRange(4, 6)); +// EXPECT_THAT(3, Not(InClosedRange(2, 4))); +// +// would generate two failures that contain the text: +// +// Expected: in closed range (4, 6) +// ... +// Expected: not (in closed range (2, 4)) +// +// Types of Matcher Parameters +// =========================== +// +// For the purpose of typing, you can view +// +// MATCHER_Pk(Foo, p1, ..., pk, description_string) { ... } +// +// as shorthand for +// +// template <typename p1_type, ..., typename pk_type> +// FooMatcherPk<p1_type, ..., pk_type> +// Foo(p1_type p1, ..., pk_type pk) { ... } +// +// When you write Foo(v1, ..., vk), the compiler infers the types of +// the parameters v1, ..., and vk for you. If you are not happy with +// the result of the type inference, you can specify the types by +// explicitly instantiating the template, as in Foo<long, bool>(5, +// false). As said earlier, you don't get to (or need to) specify +// 'arg_type' as that's determined by the context in which the matcher +// is used. You can assign the result of expression Foo(p1, ..., pk) +// to a variable of type FooMatcherPk<p1_type, ..., pk_type>. This +// can be useful when composing matchers. +// +// While you can instantiate a matcher template with reference types, +// passing the parameters by pointer usually makes your code more +// readable. If, however, you still want to pass a parameter by +// reference, be aware that in the failure message generated by the +// matcher you will see the value of the referenced object but not its +// address. +// +// Explaining Match Results +// ======================== +// +// Sometimes the matcher description alone isn't enough to explain why +// the match has failed or succeeded. For example, when expecting a +// long string, it can be very helpful to also print the diff between +// the expected string and the actual one. To achieve that, you can +// optionally stream additional information to a special variable +// named result_listener, whose type is a pointer to class +// MatchResultListener: +// +// MATCHER_P(EqualsLongString, str, "") { +// if (arg == str) return true; +// +// *result_listener << "the difference: " +/// << DiffStrings(str, arg); +// return false; +// } +// +// Overloading Matchers +// ==================== +// +// You can overload matchers with different numbers of parameters: +// +// MATCHER_P(Blah, a, description_string1) { ... } +// MATCHER_P2(Blah, a, b, description_string2) { ... } +// +// Caveats +// ======= +// +// When defining a new matcher, you should also consider implementing +// MatcherInterface or using MakePolymorphicMatcher(). These +// approaches require more work than the MATCHER* macros, but also +// give you more control on the types of the value being matched and +// the matcher parameters, which may leads to better compiler error +// messages when the matcher is used wrong. They also allow +// overloading matchers based on parameter types (as opposed to just +// based on the number of parameters). +// +// MATCHER*() can only be used in a namespace scope as templates cannot be +// declared inside of a local class. +// +// More Information +// ================ +// +// To learn more about using these macros, please search for 'MATCHER' +// on +// https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md +// +// This file also implements some commonly used argument matchers. More // matchers can be defined by the user implementing the // MatcherInterface<T> interface if necessary. // @@ -4607,6 +4820,31 @@ PolymorphicMatcher<internal::variant_matcher::VariantMatcher<T> > VariantWith( #define EXPECT_THAT(value, matcher) EXPECT_PRED_FORMAT1(\ ::testing::internal::MakePredicateFormatterFromMatcher(matcher), value) +// MATCHER* macroses itself are listed below. +#define MATCHER(name, description) GMOCK_INTERNAL_MATCHER(name, description) +#define MATCHER_P(name, p0, description) \ + GMOCK_INTERNAL_MATCHER_P(name, description, p0) +#define MATCHER_P2(name, p0, p1, description) \ + GMOCK_INTERNAL_MATCHER_P2(name, description, p0, p1) +#define MATCHER_P3(name, p0, p1, p2, description) \ + GMOCK_INTERNAL_MATCHER_P3(name, description, p0, p1, p2) +#define MATCHER_P4(name, p0, p1, p2, p3, description) \ + GMOCK_INTERNAL_MATCHER_P4(name, description, p0, p1, p2, p3) +#define MATCHER_P5(name, p0, p1, p2, p3, p4, description) \ + GMOCK_INTERNAL_MATCHER_P5(name, description, p0, p1, p2, p3, p4) +#define MATCHER_P6(name, p0, p1, p2, p3, p4, p5, description) \ + GMOCK_INTERNAL_MATCHER_P6(name, description, p0, p1, p2, p3, p4, p5) +#define MATCHER_P7(name, p0, p1, p2, p3, p4, p5, p6, description) \ + GMOCK_INTERNAL_MATCHER_P7(name, description, p0, p1, p2, p3, p4, p5, p6) +#define MATCHER_P8(name, p0, p1, p2, p3, p4, p5, p6, p7, description) \ + GMOCK_INTERNAL_MATCHER_P8(name, description, p0, p1, p2, p3, p4, p5, p6, p7) +#define MATCHER_P9(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, description) \ + GMOCK_INTERNAL_MATCHER_P9(name, description, p0, p1, p2, p3, p4, p5, p6, p7, \ + p8) +#define MATCHER_P10(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, description) \ + GMOCK_INTERNAL_MATCHER_P10(name, description, p0, p1, p2, p3, p4, p5, p6, \ + p7, p8, p9) + } // namespace testing GTEST_DISABLE_MSC_WARNINGS_POP_() // 4251 5046 |