catch2/examples/301-Gen-MapTypeConversion.cpp
Martin Jeřábek cde3509664 Fix various useful clang-tidy warnings
* bugprone-branch-clone
* bugprone-copy-constructor-init
* bugprone-empty-catch
* bugprone-sizeof-expression
* bugprone-switch-missing-default-case
* bugprone-unused-local-non-trivial-variable
* clang-analyzer-core.uninitialized.Assign
* clang-analyzer-cplusplus.Move
* clang-analyzer-optin.cplusplus.VirtualCall
* modernize-loop-convert
* modernize-raw-string-literal
* modernize-use-equals-default
* modernize-use-override
* modernize-use-using
* performance-avoid-endl
* performance-inefficient-string-concatenation
* performance-inefficient-vector-operation
* performance-noexcept-move-constructor
* performance-unnecessary-value-param (and improve generator example)
* readability-duplicate-include
* readability-inconsistent-declaration-parameter-name
* readability-non-const-parameter
* readability-redundant-casting
* readability-redundant-member-init
* readability-redundant-smartptr-get
* readability-static-accessed-through-instance
* unused variable in amalgamted tests
2024-03-01 21:24:45 +01:00

70 lines
2.1 KiB
C++

// Copyright Catch2 Authors
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.txt or copy at
// https://www.boost.org/LICENSE_1_0.txt)
// SPDX-License-Identifier: BSL-1.0
// 301-Gen-MapTypeConversion.cpp
// Shows how to use map to modify generator's return type.
// Specifically we wrap a std::string returning generator with a generator
// that converts the strings using stoi, so the returned type is actually
// an int.
#include <catch2/catch_test_macros.hpp>
#include <catch2/generators/catch_generators_adapters.hpp>
#include <string>
#include <sstream>
namespace {
// Returns a line from a stream. You could have it e.g. read lines from
// a file, but to avoid problems with paths in examples, we will use
// a fixed stringstream.
class LineGenerator final : public Catch::Generators::IGenerator<std::string> {
std::string m_line;
std::stringstream m_stream;
public:
explicit LineGenerator( std::string const& lines ) {
m_stream.str( lines );
if (!next()) {
Catch::Generators::Detail::throw_generator_exception("Couldn't read a single line");
}
}
std::string const& get() const override;
bool next() override {
return !!std::getline(m_stream, m_line);
}
};
std::string const& LineGenerator::get() const {
return m_line;
}
// This helper function provides a nicer UX when instantiating the generator
// Notice that it returns an instance of GeneratorWrapper<std::string>, which
// is a value-wrapper around std::unique_ptr<IGenerator<std::string>>.
Catch::Generators::GeneratorWrapper<std::string>
lines( std::string const& lines ) {
return Catch::Generators::GeneratorWrapper<std::string>(
new LineGenerator( lines ) );
}
} // end anonymous namespace
TEST_CASE("filter can convert types inside the generator expression", "[example][generator]") {
auto num = GENERATE(
map<int>( []( std::string const& line ) { return std::stoi( line ); },
lines( "1\n2\n3\n4\n" ) ) );
REQUIRE(num > 0);
}
// Compiling and running this file will result in 4 successful assertions