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Diffstat (limited to 'mfbt/tests/TestResult.cpp')
| -rw-r--r-- | mfbt/tests/TestResult.cpp | 629 |
1 files changed, 629 insertions, 0 deletions
diff --git a/mfbt/tests/TestResult.cpp b/mfbt/tests/TestResult.cpp new file mode 100644 index 0000000000..3c221d6f86 --- /dev/null +++ b/mfbt/tests/TestResult.cpp @@ -0,0 +1,629 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include <string.h> +#include "mozilla/ResultVariant.h" +#include "mozilla/UniquePtr.h" + +using mozilla::Err; +using mozilla::GenericErrorResult; +using mozilla::Ok; +using mozilla::Result; +using mozilla::UniquePtr; + +enum struct TestUnusedZeroEnum : int16_t { Ok = 0, NotOk = 1 }; + +namespace mozilla::detail { +template <> +struct UnusedZero<TestUnusedZeroEnum> : UnusedZeroEnum<TestUnusedZeroEnum> {}; +} // namespace mozilla::detail + +struct Failed {}; + +namespace mozilla::detail { +template <> +struct UnusedZero<Failed> { + using StorageType = uintptr_t; + + static constexpr bool value = true; + static constexpr StorageType nullValue = 0; + static constexpr StorageType GetDefaultValue() { return 2; } + + static constexpr void AssertValid(StorageType aValue) {} + static constexpr Failed Inspect(const StorageType& aValue) { + return Failed{}; + } + static constexpr Failed Unwrap(StorageType aValue) { return Failed{}; } + static constexpr StorageType Store(Failed aValue) { + return GetDefaultValue(); + } +}; + +} // namespace mozilla::detail + +// V is trivially default-constructible, and E has UnusedZero<E>::value == true, +// for a reference type and for a non-reference type +static_assert(mozilla::detail::SelectResultImpl<uintptr_t, Failed>::value == + mozilla::detail::PackingStrategy::NullIsOk); +static_assert( + mozilla::detail::SelectResultImpl<Ok, TestUnusedZeroEnum>::value == + mozilla::detail::PackingStrategy::NullIsOk); +static_assert(mozilla::detail::SelectResultImpl<Ok, Failed>::value == + mozilla::detail::PackingStrategy::LowBitTagIsError); + +static_assert(std::is_trivially_destructible_v<Result<uintptr_t, Failed>>); +static_assert(std::is_trivially_destructible_v<Result<Ok, TestUnusedZeroEnum>>); +static_assert(std::is_trivially_destructible_v<Result<Ok, Failed>>); + +static_assert( + sizeof(Result<bool, TestUnusedZeroEnum>) <= sizeof(uintptr_t), + "Result with bool value type should not be larger than pointer-sized"); +static_assert(sizeof(Result<Ok, Failed>) == sizeof(uint8_t), + "Result with empty value type should be size 1"); +static_assert(sizeof(Result<int*, Failed>) == sizeof(uintptr_t), + "Result with two aligned pointer types should be pointer-sized"); +static_assert( + sizeof(Result<char*, Failed*>) > sizeof(char*), + "Result with unaligned success type `char*` must not be pointer-sized"); +static_assert( + sizeof(Result<int*, char*>) > sizeof(char*), + "Result with unaligned error type `char*` must not be pointer-sized"); + +enum Foo8 : uint8_t {}; +enum Foo16 : uint16_t {}; +enum Foo32 : uint32_t {}; +static_assert(sizeof(Result<Ok, Foo8>) <= sizeof(uintptr_t), + "Result with small types should be pointer-sized"); +static_assert(sizeof(Result<Ok, Foo16>) <= sizeof(uintptr_t), + "Result with small types should be pointer-sized"); +static_assert(sizeof(Foo32) >= sizeof(uintptr_t) || + sizeof(Result<Ok, Foo32>) <= sizeof(uintptr_t), + "Result with small types should be pointer-sized"); + +static_assert(sizeof(Result<Foo16, Foo8>) <= sizeof(uintptr_t), + "Result with small types should be pointer-sized"); +static_assert(sizeof(Result<Foo8, Foo16>) <= sizeof(uintptr_t), + "Result with small types should be pointer-sized"); +static_assert(sizeof(Foo32) >= sizeof(uintptr_t) || + sizeof(Result<Foo32, Foo16>) <= sizeof(uintptr_t), + "Result with small types should be pointer-sized"); +static_assert(sizeof(Foo32) >= sizeof(uintptr_t) || + sizeof(Result<Foo16, Foo32>) <= sizeof(uintptr_t), + "Result with small types should be pointer-sized"); + +static GenericErrorResult<Failed> Fail() { + static Failed failed; + return Err(failed); +} + +static GenericErrorResult<TestUnusedZeroEnum> FailTestUnusedZeroEnum() { + return Err(TestUnusedZeroEnum::NotOk); +} + +static Result<Ok, Failed> Task1(bool pass) { + if (!pass) { + return Fail(); // implicit conversion from GenericErrorResult to Result + } + return Ok(); +} + +static Result<Ok, TestUnusedZeroEnum> Task1UnusedZeroEnumErr(bool pass) { + if (!pass) { + return FailTestUnusedZeroEnum(); // implicit conversion from + // GenericErrorResult to Result + } + return Ok(); +} + +static Result<int, Failed> Task2(bool pass, int value) { + MOZ_TRY( + Task1(pass)); // converts one type of result to another in the error case + return value; // implicit conversion from T to Result<T, E> +} + +static Result<int, TestUnusedZeroEnum> Task2UnusedZeroEnumErr(bool pass, + int value) { + MOZ_TRY(Task1UnusedZeroEnumErr( + pass)); // converts one type of result to another in the error case + return value; // implicit conversion from T to Result<T, E> +} + +static Result<int, Failed> Task3(bool pass1, bool pass2, int value) { + int x, y; + MOZ_TRY_VAR(x, Task2(pass1, value)); + MOZ_TRY_VAR(y, Task2(pass2, value)); + return x + y; +} + +static void BasicTests() { + MOZ_RELEASE_ASSERT(Task1(true).isOk()); + MOZ_RELEASE_ASSERT(!Task1(true).isErr()); + MOZ_RELEASE_ASSERT(!Task1(false).isOk()); + MOZ_RELEASE_ASSERT(Task1(false).isErr()); + + MOZ_RELEASE_ASSERT(Task1UnusedZeroEnumErr(true).isOk()); + MOZ_RELEASE_ASSERT(!Task1UnusedZeroEnumErr(true).isErr()); + MOZ_RELEASE_ASSERT(!Task1UnusedZeroEnumErr(false).isOk()); + MOZ_RELEASE_ASSERT(Task1UnusedZeroEnumErr(false).isErr()); + MOZ_RELEASE_ASSERT(TestUnusedZeroEnum::NotOk == + Task1UnusedZeroEnumErr(false).inspectErr()); + MOZ_RELEASE_ASSERT(TestUnusedZeroEnum::NotOk == + Task1UnusedZeroEnumErr(false).unwrapErr()); + + // MOZ_TRY works. + MOZ_RELEASE_ASSERT(Task2(true, 3).isOk()); + MOZ_RELEASE_ASSERT(Task2(true, 3).unwrap() == 3); + MOZ_RELEASE_ASSERT(Task2(true, 3).unwrapOr(6) == 3); + MOZ_RELEASE_ASSERT(Task2(false, 3).isErr()); + MOZ_RELEASE_ASSERT(Task2(false, 3).unwrapOr(6) == 6); + + MOZ_RELEASE_ASSERT(Task2UnusedZeroEnumErr(true, 3).isOk()); + MOZ_RELEASE_ASSERT(Task2UnusedZeroEnumErr(true, 3).unwrap() == 3); + MOZ_RELEASE_ASSERT(Task2UnusedZeroEnumErr(true, 3).unwrapOr(6) == 3); + MOZ_RELEASE_ASSERT(Task2UnusedZeroEnumErr(false, 3).isErr()); + MOZ_RELEASE_ASSERT(Task2UnusedZeroEnumErr(false, 3).unwrapOr(6) == 6); + + // MOZ_TRY_VAR works. + MOZ_RELEASE_ASSERT(Task3(true, true, 3).isOk()); + MOZ_RELEASE_ASSERT(Task3(true, true, 3).unwrap() == 6); + MOZ_RELEASE_ASSERT(Task3(true, false, 3).isErr()); + MOZ_RELEASE_ASSERT(Task3(false, true, 3).isErr()); + MOZ_RELEASE_ASSERT(Task3(false, true, 3).unwrapOr(6) == 6); + + // Lvalues should work too. + { + Result<Ok, Failed> res = Task1(true); + MOZ_RELEASE_ASSERT(res.isOk()); + MOZ_RELEASE_ASSERT(!res.isErr()); + + res = Task1(false); + MOZ_RELEASE_ASSERT(!res.isOk()); + MOZ_RELEASE_ASSERT(res.isErr()); + } + + { + Result<int, Failed> res = Task2(true, 3); + MOZ_RELEASE_ASSERT(res.isOk()); + MOZ_RELEASE_ASSERT(res.unwrap() == 3); + + res = Task2(false, 4); + MOZ_RELEASE_ASSERT(res.isErr()); + } + + // Some tests for pointer tagging. + { + int i = 123; + + Result<int*, Failed> res = &i; + static_assert(sizeof(res) == sizeof(uintptr_t), + "should use pointer tagging to fit in a word"); + + MOZ_RELEASE_ASSERT(res.isOk()); + MOZ_RELEASE_ASSERT(*res.unwrap() == 123); + + res = Err(Failed()); + MOZ_RELEASE_ASSERT(res.isErr()); + } +} + +struct NonCopyableNonMovable { + explicit NonCopyableNonMovable(uint32_t aValue) : mValue(aValue) {} + + NonCopyableNonMovable(const NonCopyableNonMovable&) = delete; + NonCopyableNonMovable(NonCopyableNonMovable&&) = delete; + NonCopyableNonMovable& operator=(const NonCopyableNonMovable&) = delete; + NonCopyableNonMovable& operator=(NonCopyableNonMovable&&) = delete; + + uint32_t mValue; +}; + +static void InPlaceConstructionTests() { + { + // PackingStrategy == NullIsOk + static_assert(mozilla::detail::SelectResultImpl<NonCopyableNonMovable, + Failed>::value == + mozilla::detail::PackingStrategy::NullIsOk); + const Result<NonCopyableNonMovable, Failed> result{std::in_place, 42}; + MOZ_RELEASE_ASSERT(42 == result.inspect().mValue); + } + + { + // PackingStrategy == Variant + static_assert( + mozilla::detail::SelectResultImpl<NonCopyableNonMovable, int>::value == + mozilla::detail::PackingStrategy::Variant); + const Result<NonCopyableNonMovable, int> result{std::in_place, 42}; + MOZ_RELEASE_ASSERT(42 == result.inspect().mValue); + } +} + +/* * */ + +struct Snafu : Failed {}; + +static Result<Ok, Snafu*> Explode() { + static Snafu snafu; + return Err(&snafu); +} + +static Result<Ok, Failed*> ErrorGeneralization() { + MOZ_TRY(Explode()); // change error type from Snafu* to more general Failed* + return Ok(); +} + +static void TypeConversionTests() { + MOZ_RELEASE_ASSERT(ErrorGeneralization().isErr()); + + { + const Result<Ok, Failed*> res = Explode(); + MOZ_RELEASE_ASSERT(res.isErr()); + } + + { + const Result<Ok, Failed*> res = Result<Ok, Snafu*>{Ok{}}; + MOZ_RELEASE_ASSERT(res.isOk()); + } +} + +static void EmptyValueTest() { + struct Fine {}; + mozilla::Result<Fine, Failed> res((Fine())); + res.unwrap(); + MOZ_RELEASE_ASSERT(res.isOk()); + static_assert(sizeof(res) == sizeof(uint8_t), + "Result with empty value and error types should be size 1"); +} + +static void MapTest() { + struct MyError { + int x; + + explicit MyError(int y) : x(y) {} + }; + + // Mapping over success values, to the same success type. + { + Result<int, MyError> res(5); + bool invoked = false; + auto res2 = res.map([&invoked](int x) { + MOZ_RELEASE_ASSERT(x == 5); + invoked = true; + return 6; + }); + MOZ_RELEASE_ASSERT(res2.isOk()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(res2.unwrap() == 6); + } + + // Mapping over success values, to a different success type. + { + Result<int, MyError> res(5); + bool invoked = false; + auto res2 = res.map([&invoked](int x) { + MOZ_RELEASE_ASSERT(x == 5); + invoked = true; + return "hello"; + }); + MOZ_RELEASE_ASSERT(res2.isOk()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(strcmp(res2.unwrap(), "hello") == 0); + } + + // Mapping over error values. + { + MyError err(1); + Result<char, MyError> res(err); + MOZ_RELEASE_ASSERT(res.isErr()); + Result<char, MyError> res2 = res.map([](int x) { + MOZ_RELEASE_ASSERT(false); + return 'a'; + }); + MOZ_RELEASE_ASSERT(res2.isErr()); + MOZ_RELEASE_ASSERT(res2.unwrapErr().x == err.x); + } + + // Function pointers instead of lambdas as the mapping function. + { + Result<const char*, MyError> res("hello"); + auto res2 = res.map(strlen); + MOZ_RELEASE_ASSERT(res2.isOk()); + MOZ_RELEASE_ASSERT(res2.unwrap() == 5); + } +} + +static void MapErrTest() { + struct MyError { + int x; + + explicit MyError(int y) : x(y) {} + }; + + struct MyError2 { + int a; + + explicit MyError2(int b) : a(b) {} + }; + + // Mapping over error values, to the same error type. + { + MyError err(1); + Result<char, MyError> res(err); + MOZ_RELEASE_ASSERT(res.isErr()); + bool invoked = false; + auto res2 = res.mapErr([&invoked](const auto err) { + MOZ_RELEASE_ASSERT(err.x == 1); + invoked = true; + return MyError(2); + }); + MOZ_RELEASE_ASSERT(res2.isErr()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(res2.unwrapErr().x == 2); + } + + // Mapping over error values, to a different error type. + { + MyError err(1); + Result<char, MyError> res(err); + MOZ_RELEASE_ASSERT(res.isErr()); + bool invoked = false; + auto res2 = res.mapErr([&invoked](const auto err) { + MOZ_RELEASE_ASSERT(err.x == 1); + invoked = true; + return MyError2(2); + }); + MOZ_RELEASE_ASSERT(res2.isErr()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(res2.unwrapErr().a == 2); + } + + // Mapping over success values. + { + Result<int, MyError> res(5); + auto res2 = res.mapErr([](const auto err) { + MOZ_RELEASE_ASSERT(false); + return MyError(1); + }); + MOZ_RELEASE_ASSERT(res2.isOk()); + MOZ_RELEASE_ASSERT(res2.unwrap() == 5); + } + + // Function pointers instead of lambdas as the mapping function. + { + Result<Ok, const char*> res("hello"); + auto res2 = res.mapErr(strlen); + MOZ_RELEASE_ASSERT(res2.isErr()); + MOZ_RELEASE_ASSERT(res2.unwrapErr() == 5); + } +} + +static Result<Ok, size_t> strlen_ResultWrapper(const char* aValue) { + return Err(strlen(aValue)); +} + +static void OrElseTest() { + struct MyError { + int x; + + explicit MyError(int y) : x(y) {} + }; + + struct MyError2 { + int a; + + explicit MyError2(int b) : a(b) {} + }; + + // `orElse`ing over error values, to Result<V, E> (the same error type) error + // variant. + { + MyError err(1); + Result<char, MyError> res(err); + MOZ_RELEASE_ASSERT(res.isErr()); + bool invoked = false; + auto res2 = res.orElse([&invoked](const auto err) -> Result<char, MyError> { + MOZ_RELEASE_ASSERT(err.x == 1); + invoked = true; + if (err.x != 42) { + return Err(MyError(2)); + } + return 'a'; + }); + MOZ_RELEASE_ASSERT(res2.isErr()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(res2.unwrapErr().x == 2); + } + + // `orElse`ing over error values, to Result<V, E> (the same error type) + // success variant. + { + MyError err(42); + Result<char, MyError> res(err); + MOZ_RELEASE_ASSERT(res.isErr()); + bool invoked = false; + auto res2 = res.orElse([&invoked](const auto err) -> Result<char, MyError> { + MOZ_RELEASE_ASSERT(err.x == 42); + invoked = true; + if (err.x != 42) { + return Err(MyError(2)); + } + return 'a'; + }); + MOZ_RELEASE_ASSERT(res2.isOk()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(res2.unwrap() == 'a'); + } + + // `orElse`ing over error values, to Result<V, E2> (a different error type) + // error variant. + { + MyError err(1); + Result<char, MyError> res(err); + MOZ_RELEASE_ASSERT(res.isErr()); + bool invoked = false; + auto res2 = + res.orElse([&invoked](const auto err) -> Result<char, MyError2> { + MOZ_RELEASE_ASSERT(err.x == 1); + invoked = true; + if (err.x != 42) { + return Err(MyError2(2)); + } + return 'a'; + }); + MOZ_RELEASE_ASSERT(res2.isErr()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(res2.unwrapErr().a == 2); + } + + // `orElse`ing over error values, to Result<V, E2> (a different error type) + // success variant. + { + MyError err(42); + Result<char, MyError> res(err); + MOZ_RELEASE_ASSERT(res.isErr()); + bool invoked = false; + auto res2 = + res.orElse([&invoked](const auto err) -> Result<char, MyError2> { + MOZ_RELEASE_ASSERT(err.x == 42); + invoked = true; + if (err.x != 42) { + return Err(MyError2(2)); + } + return 'a'; + }); + MOZ_RELEASE_ASSERT(res2.isOk()); + MOZ_RELEASE_ASSERT(invoked); + MOZ_RELEASE_ASSERT(res2.unwrap() == 'a'); + } + + // `orElse`ing over success values. + { + Result<int, MyError> res(5); + auto res2 = res.orElse([](const auto err) -> Result<int, MyError> { + MOZ_RELEASE_ASSERT(false); + return Err(MyError(1)); + }); + MOZ_RELEASE_ASSERT(res2.isOk()); + MOZ_RELEASE_ASSERT(res2.unwrap() == 5); + } + + // Function pointers instead of lambdas as the `orElse`ing function. + { + Result<Ok, const char*> res("hello"); + auto res2 = res.orElse(strlen_ResultWrapper); + MOZ_RELEASE_ASSERT(res2.isErr()); + MOZ_RELEASE_ASSERT(res2.unwrapErr() == 5); + } +} + +static void AndThenTest() { + // `andThen`ing over success results. + { + Result<int, const char*> r1(10); + Result<int, const char*> r2 = + r1.andThen([](int x) { return Result<int, const char*>(x + 1); }); + MOZ_RELEASE_ASSERT(r2.isOk()); + MOZ_RELEASE_ASSERT(r2.unwrap() == 11); + } + + // `andThen`ing over error results. + { + Result<int, const char*> r3("error"); + Result<int, const char*> r4 = r3.andThen([](int x) { + MOZ_RELEASE_ASSERT(false); + return Result<int, const char*>(1); + }); + MOZ_RELEASE_ASSERT(r4.isErr()); + MOZ_RELEASE_ASSERT(r3.unwrapErr() == r4.unwrapErr()); + } + + // andThen with a function accepting an rvalue + { + Result<int, const char*> r1(10); + Result<int, const char*> r2 = + r1.andThen([](int&& x) { return Result<int, const char*>(x + 1); }); + MOZ_RELEASE_ASSERT(r2.isOk()); + MOZ_RELEASE_ASSERT(r2.unwrap() == 11); + } +} + +using UniqueResult = Result<UniquePtr<int>, const char*>; + +static UniqueResult UniqueTask() { return mozilla::MakeUnique<int>(3); } +static UniqueResult UniqueTaskError() { return Err("bad"); } + +using UniqueErrorResult = Result<int, UniquePtr<int>>; +static UniqueErrorResult UniqueError() { + return Err(mozilla::MakeUnique<int>(4)); +} + +static Result<Ok, UniquePtr<int>> TryUniqueErrorResult() { + MOZ_TRY(UniqueError()); + return Ok(); +} + +static void UniquePtrTest() { + { + auto result = UniqueTask(); + MOZ_RELEASE_ASSERT(result.isOk()); + auto ptr = result.unwrap(); + MOZ_RELEASE_ASSERT(ptr); + MOZ_RELEASE_ASSERT(*ptr == 3); + auto moved = result.unwrap(); + MOZ_RELEASE_ASSERT(!moved); + } + + { + auto err = UniqueTaskError(); + MOZ_RELEASE_ASSERT(err.isErr()); + auto ptr = err.unwrapOr(mozilla::MakeUnique<int>(4)); + MOZ_RELEASE_ASSERT(ptr); + MOZ_RELEASE_ASSERT(*ptr == 4); + } + + { + auto result = UniqueTaskError(); + result = UniqueResult(mozilla::MakeUnique<int>(6)); + MOZ_RELEASE_ASSERT(result.isOk()); + MOZ_RELEASE_ASSERT(result.inspect() && *result.inspect() == 6); + } + + { + auto result = UniqueError(); + MOZ_RELEASE_ASSERT(result.isErr()); + MOZ_RELEASE_ASSERT(result.inspectErr()); + MOZ_RELEASE_ASSERT(*result.inspectErr() == 4); + auto err = result.unwrapErr(); + MOZ_RELEASE_ASSERT(!result.inspectErr()); + MOZ_RELEASE_ASSERT(err); + MOZ_RELEASE_ASSERT(*err == 4); + + result = UniqueErrorResult(0); + MOZ_RELEASE_ASSERT(result.isOk() && result.unwrap() == 0); + } + + { + auto result = TryUniqueErrorResult(); + MOZ_RELEASE_ASSERT(result.isErr()); + auto err = result.unwrapErr(); + MOZ_RELEASE_ASSERT(err && *err == 4); + MOZ_RELEASE_ASSERT(!result.inspectErr()); + } +} + +/* * */ + +int main() { + BasicTests(); + InPlaceConstructionTests(); + TypeConversionTests(); + EmptyValueTest(); + MapTest(); + MapErrTest(); + OrElseTest(); + AndThenTest(); + UniquePtrTest(); + return 0; +} |