llvm-project/clang-tools-extra/clangd/unittests/Matchers.h

200 lines
7.1 KiB
C++

//===-- Matchers.h ----------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// GMock matchers that aren't specific to particular tests.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLS_EXTRA_UNITTESTS_CLANGD_MATCHERS_H
#define LLVM_CLANG_TOOLS_EXTRA_UNITTESTS_CLANGD_MATCHERS_H
#include "Protocol.h"
#include "gmock/gmock.h"
namespace clang {
namespace clangd {
using ::testing::Matcher;
// EXPECT_IFF expects matcher if condition is true, and Not(matcher) if false.
// This is hard to write as a function, because matchers may be polymorphic.
#define EXPECT_IFF(condition, value, matcher) \
do { \
if (condition) \
EXPECT_THAT(value, matcher); \
else \
EXPECT_THAT(value, ::testing::Not(matcher)); \
} while (0)
// HasSubsequence(m1, m2, ...) matches a vector containing elements that match
// m1, m2 ... in that order.
//
// SubsequenceMatcher implements this once the type of vector is known.
template <typename T>
class SubsequenceMatcher
: public ::testing::MatcherInterface<const std::vector<T> &> {
std::vector<Matcher<T>> Matchers;
public:
SubsequenceMatcher(std::vector<Matcher<T>> M) : Matchers(M) {}
void DescribeTo(std::ostream *OS) const override {
*OS << "Contains the subsequence [";
const char *Sep = "";
for (const auto &M : Matchers) {
*OS << Sep;
M.DescribeTo(OS);
Sep = ", ";
}
*OS << "]";
}
bool MatchAndExplain(const std::vector<T> &V,
::testing::MatchResultListener *L) const override {
std::vector<int> Matches(Matchers.size());
size_t I = 0;
for (size_t J = 0; I < Matchers.size() && J < V.size(); ++J)
if (Matchers[I].Matches(V[J]))
Matches[I++] = J;
if (I == Matchers.size()) // We exhausted all matchers.
return true;
if (L->IsInterested()) {
*L << "\n Matched:";
for (size_t K = 0; K < I; ++K) {
*L << "\n\t";
Matchers[K].DescribeTo(L->stream());
*L << " ==> " << ::testing::PrintToString(V[Matches[K]]);
}
*L << "\n\t";
Matchers[I].DescribeTo(L->stream());
*L << " ==> no subsequent match";
}
return false;
}
};
// PolySubsequenceMatcher implements a "polymorphic" SubsequenceMatcher.
// It captures the types of the element matchers, and can be converted to
// Matcher<vector<T>> if each matcher can be converted to Matcher<T>.
// This allows HasSubsequence() to accept polymorphic matchers like Not().
template <typename... M> class PolySubsequenceMatcher {
std::tuple<M...> Matchers;
public:
PolySubsequenceMatcher(M &&... Args)
: Matchers(std::make_tuple(std::forward<M>(Args)...)) {}
template <typename T> operator Matcher<const std::vector<T> &>() const {
return ::testing::MakeMatcher(new SubsequenceMatcher<T>(
TypedMatchers<T>(llvm::index_sequence_for<M...>{})));
}
private:
template <typename T, size_t... I>
std::vector<Matcher<T>> TypedMatchers(llvm::index_sequence<I...>) const {
return {std::get<I>(Matchers)...};
}
};
// HasSubsequence(m1, m2, ...) matches a vector containing elements that match
// m1, m2 ... in that order.
// The real implementation is in SubsequenceMatcher.
template <typename... Args>
PolySubsequenceMatcher<Args...> HasSubsequence(Args &&... M) {
return PolySubsequenceMatcher<Args...>(std::forward<Args>(M)...);
}
// EXPECT_ERROR seems like a pretty generic name, make sure it's not defined
// already.
#ifdef EXPECT_ERROR
#error "Refusing to redefine EXPECT_ERROR"
#endif
// Consumes llvm::Expected<T>, checks it contains an error and marks it as
// handled.
#define EXPECT_ERROR(expectedValue) \
do { \
auto &&ComputedValue = (expectedValue); \
if (ComputedValue) { \
ADD_FAILURE() << "expected an error from " << #expectedValue \
<< " but got " \
<< ::testing::PrintToString(*ComputedValue); \
break; \
} \
llvm::consumeError(ComputedValue.takeError()); \
} while (false)
// Implements the HasValue(m) matcher for matching an Optional whose
// value matches matcher m.
template <typename InnerMatcher> class OptionalMatcher {
public:
explicit OptionalMatcher(const InnerMatcher &matcher) : matcher_(matcher) {}
// This type conversion operator template allows Optional(m) to be
// used as a matcher for any Optional type whose value type is
// compatible with the inner matcher.
//
// The reason we do this instead of relying on
// MakePolymorphicMatcher() is that the latter is not flexible
// enough for implementing the DescribeTo() method of Optional().
template <typename Optional> operator Matcher<Optional>() const {
return MakeMatcher(new Impl<Optional>(matcher_));
}
private:
// The monomorphic implementation that works for a particular optional type.
template <typename Optional>
class Impl : public ::testing::MatcherInterface<Optional> {
public:
using Value = typename std::remove_const<
typename std::remove_reference<Optional>::type>::type::value_type;
explicit Impl(const InnerMatcher &matcher)
: matcher_(::testing::MatcherCast<const Value &>(matcher)) {}
virtual void DescribeTo(::std::ostream *os) const {
*os << "has a value that ";
matcher_.DescribeTo(os);
}
virtual void DescribeNegationTo(::std::ostream *os) const {
*os << "does not have a value that ";
matcher_.DescribeTo(os);
}
virtual bool
MatchAndExplain(Optional optional,
::testing::MatchResultListener *listener) const {
if (!optional.hasValue())
return false;
*listener << "which has a value ";
return MatchPrintAndExplain(*optional, matcher_, listener);
}
private:
const Matcher<const Value &> matcher_;
GTEST_DISALLOW_ASSIGN_(Impl);
};
const InnerMatcher matcher_;
GTEST_DISALLOW_ASSIGN_(OptionalMatcher);
};
// Creates a matcher that matches an Optional that has a value
// that matches inner_matcher.
template <typename InnerMatcher>
inline OptionalMatcher<InnerMatcher>
HasValue(const InnerMatcher &inner_matcher) {
return OptionalMatcher<InnerMatcher>(inner_matcher);
}
} // namespace clangd
} // namespace clang
#endif