Put back files for now

We'll revert this sometime later

tests/unit/libutil-support/.version

@@ -0,0 +1 @@
+../../../.version

tests/unit/libutil-support/build-utils-meson

@@ -0,0 +1 @@
+../../../build-utils-meson/

tests/unit/libutil-support/meson.build

@@ -0,0 +1,70 @@
+project('nix-util-test-support', 'cpp',
+  version : files('.version'),
+  default_options : [
+    'cpp_std=c++2a',
+    # TODO(Qyriad): increase the warning level
+    'warning_level=1',
+    'debug=true',
+    'optimization=2',
+    'errorlogs=true', # Please print logs for tests that fail
+  ],
+  meson_version : '>= 1.1',
+  license : 'LGPL-2.1-or-later',
+)
+
+cxx = meson.get_compiler('cpp')
+
+subdir('build-utils-meson/deps-lists')
+
+deps_private_maybe_subproject = [
+]
+deps_public_maybe_subproject = [
+  dependency('nix-util'),
+]
+subdir('build-utils-meson/subprojects')
+
+rapidcheck = dependency('rapidcheck')
+deps_public += rapidcheck
+
+add_project_arguments(
+  # TODO(Qyriad): Yes this is how the autoconf+Make system did it.
+  # It would be nice for our headers to be idempotent instead.
+  '-include', 'config-util.hh',
+  language : 'cpp',
+)
+
+subdir('build-utils-meson/diagnostics')
+
+sources = files(
+  'tests/hash.cc',
+  'tests/string_callback.cc',
+)
+
+include_dirs = [include_directories('.')]
+
+headers = files(
+  'tests/characterization.hh',
+  'tests/hash.hh',
+  'tests/nix_api_util.hh',
+  'tests/string_callback.hh',
+)
+
+subdir('build-utils-meson/export-all-symbols')
+
+this_library = library(
+  'nix-util-test-support',
+  sources,
+  dependencies : deps_public + deps_private + deps_other,
+  include_directories : include_dirs,
+  # TODO: Remove `-lrapidcheck` when https://github.com/emil-e/rapidcheck/pull/326
+  #       is available. See also ../libutil/build.meson
+  link_args: linker_export_flags + ['-lrapidcheck'],
+  prelink : true, # For C++ static initializers
+  install : true,
+)
+
+install_headers(headers, subdir : 'nix', preserve_path : true)
+
+libraries_private = []
+
+subdir('build-utils-meson/export')

tests/unit/libutil-support/package.nix

@@ -0,0 +1,81 @@
+{ lib
+, stdenv
+, mkMesonDerivation
+, releaseTools
+
+, meson
+, ninja
+, pkg-config
+
+, nix-util
+
+, rapidcheck
+
+# Configuration Options
+
+, versionSuffix ? ""
+}:
+
+let
+  inherit (lib) fileset;
+
+  version = lib.fileContents ./.version + versionSuffix;
+in
+
+mkMesonDerivation (finalAttrs: {
+  pname = "nix-util-test-support";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../../build-utils-meson
+    ./build-utils-meson
+    ../../../.version
+    ./.version
+    ./meson.build
+    # ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [
+    meson
+    ninja
+    pkg-config
+  ];
+
+  propagatedBuildInputs = [
+    nix-util
+    rapidcheck
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../../.version
+    '';
+
+  mesonFlags = [
+  ];
+
+  env = lib.optionalAttrs (stdenv.isLinux && !(stdenv.hostPlatform.isStatic && stdenv.system == "aarch64-linux")) {
+    LDFLAGS = "-fuse-ld=gold";
+  };
+
+  enableParallelBuilding = true;
+
+  separateDebugInfo = !stdenv.hostPlatform.isStatic;
+
+  strictDeps = true;
+
+  hardeningDisable = lib.optional stdenv.hostPlatform.isStatic "pie";
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})

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

@@ -0,0 +1,109 @@
+#pragma once
+///@file
+
+#include <gtest/gtest.h>
+
+#include "types.hh"
+#include "environment-variables.hh"
+#include "file-system.hh"
+
+namespace nix {
+
+/**
+ * The path to the unit test data directory. See the contributing guide
+ * in the manual for further details.
+ */
+static inline Path getUnitTestData() {
+    return getEnv("_NIX_TEST_UNIT_DATA").value();
+}
+
+/**
+ * Whether we should update "golden masters" instead of running tests
+ * against them. See the contributing guide in the manual for further
+ * details.
+ */
+static inline 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 got = test();
+
+        if (testAccept())
+        {
+            createDirs(dirOf(file));
+            writeFile2(file, got);
+            GTEST_SKIP()
+                << "Updating golden master "
+                << file;
+        }
+        else
+        {
+            decltype(got) expected = readFile2(file);
+            ASSERT_EQ(got, expected);
+        }
+    }
+
+    /**
+     * 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);
+            });
+    }
+};
+
+}

tests/unit/libutil-support/tests/hash.cc

@@ -0,0 +1,27 @@
+#include <regex>
+
+#include <rapidcheck.h>
+
+#include "hash.hh"
+
+#include "tests/hash.hh"
+
+namespace rc {
+using namespace nix;
+
+Gen<Hash> Arbitrary<Hash>::arbitrary()
+{
+    Hash prototype(HashAlgorithm::SHA1);
+    return
+        gen::apply(
+            [](const std::vector<uint8_t> & v) {
+                Hash hash(HashAlgorithm::SHA1);
+                assert(v.size() == hash.hashSize);
+                std::copy(v.begin(), v.end(), hash.hash);
+                return hash;
+            },
+            gen::container<std::vector<uint8_t>>(prototype.hashSize, gen::arbitrary<uint8_t>())
+        );
+}
+
+}

tests/unit/libutil-support/tests/hash.hh

@@ -0,0 +1,16 @@
+#pragma once
+///@file
+
+#include <rapidcheck/gen/Arbitrary.h>
+
+#include <hash.hh>
+
+namespace rc {
+using namespace nix;
+
+template<>
+struct Arbitrary<Hash> {
+    static Gen<Hash> arbitrary();
+};
+
+}

tests/unit/libutil-support/tests/nix_api_util.hh

@@ -0,0 +1,48 @@
+#pragma once
+///@file
+#include "nix_api_util.h"
+
+#include <gtest/gtest.h>
+
+namespace nixC {
+
+class nix_api_util_context : public ::testing::Test
+{
+protected:
+
+    nix_api_util_context()
+    {
+        ctx = nix_c_context_create();
+        nix_libutil_init(ctx);
+    };
+
+    ~nix_api_util_context() override
+    {
+        nix_c_context_free(ctx);
+        ctx = nullptr;
+    }
+
+    nix_c_context * ctx;
+
+    inline void assert_ctx_ok()
+    {
+
+        if (nix_err_code(ctx) == NIX_OK) {
+            return;
+        }
+        unsigned int n;
+        const char * p = nix_err_msg(nullptr, ctx, &n);
+        std::string msg(p, n);
+        FAIL() << "nix_err_code(ctx) != NIX_OK, message: " << msg;
+    }
+
+    inline void assert_ctx_err()
+    {
+        if (nix_err_code(ctx) != NIX_OK) {
+            return;
+        }
+        FAIL() << "Got NIX_OK, but expected an error!";
+    }
+};
+
+}

tests/unit/libutil-support/tests/string_callback.cc

@@ -0,0 +1,10 @@
+#include "string_callback.hh"
+
+namespace nix::testing {
+
+void observe_string_cb(const char * start, unsigned int n, std::string * user_data)
+{
+    *user_data = std::string(start);
+}
+
+}

tests/unit/libutil-support/tests/string_callback.hh

@@ -0,0 +1,16 @@
+#pragma once
+#include <string>
+
+namespace nix::testing {
+
+void observe_string_cb(const char * start, unsigned int n, std::string * user_data);
+
+inline void * observe_string_cb_data(std::string & out)
+{
+    return (void *) &out;
+};
+
+#define OBSERVE_STRING(str) \
+    (nix_get_string_callback) nix::testing::observe_string_cb, nix::testing::observe_string_cb_data(str)
+
+}