lix/tests/unit/libutil-support/tests/characterization.hh

112 lines
2.5 KiB
C++

#pragma once
///@file
#include "environment-variables.hh"
#include "file-system.hh"
#include <gtest/gtest.h>
#include <filesystem>
#include "types.hh"
#include "test-data.hh"
namespace nix {
/**
* Whether we should update "golden masters" instead of running tests
* against them. See the contributing guide in the manual for further
* details.
*/
static bool testAccept() {
return getEnv("_NIX_TEST_ACCEPT") == "1";
}
/**
* Mixin class for writing characterization tests
*/
class CharacterizationTest : public virtual ::testing::Test
{
protected:
/**
* While the "golden master" for this characterization test is
* located. It should not be shared with any other test.
*/
virtual Path goldenMaster(PathView testStem) const = 0;
public:
/**
* Golden test for reading
*
* @param test hook that takes the contents of the file and does the
* actual work
*/
void readTest(PathView testStem, auto && test)
{
auto file = goldenMaster(testStem);
if (testAccept())
{
GTEST_SKIP()
<< "Cannot read golden master "
<< file
<< "because another test is also updating it";
}
else
{
test(readFile(file));
}
}
/**
* Golden test for writing
*
* @param test hook that produces contents of the file and does the
* actual work
*/
void writeTest(
PathView testStem, auto && test, auto && readFile2, auto && writeFile2)
{
auto file = goldenMaster(testStem);
auto actual = test();
if (testAccept())
{
createDirs(dirOf(file));
writeFile2(file, actual);
GTEST_SKIP()
<< "Updating golden master "
<< file;
}
else
{
decltype(actual) expected = readFile2(file);
ASSERT_EQ(expected, actual);
}
}
/**
* Specialize to `std::string`
*/
void writeTest(PathView testStem, auto && test)
{
writeTest(
testStem, test,
[](const Path & f) -> std::string {
return readFile(f);
},
[](const Path & f, const std::string & c) {
return writeFile(f, c);
});
}
};
constexpr std::string_view cannotReadGoldenMaster =
"Cannot read golden master because another test is also updating it";
constexpr std::string_view updatingGoldenMaster =
"Updating golden master";
}