lix/src/libexpr/tests/value/context.cc
John Ericson 60b7121d2c Make the Derived Path family of types inductive for dynamic derivations
We want to be able to write down `foo.drv^bar.drv^baz`:
`foo.drv^bar.drv` is the dynamic derivation (since it is itself a
derivation output, `bar.drv` from `foo.drv`).

To that end, we create `Single{Derivation,BuiltPath}` types, that are
very similar except instead of having multiple outputs (in a set or
map), they have a single one. This is for everything to the left of the
rightmost `^`.

`NixStringContextElem` has an analogous change, and now can reuse
`SingleDerivedPath` at the top level. In fact, if we ever get rid of
`DrvDeep`, `NixStringContextElem` could be replaced with
`SingleDerivedPath` entirely!

Important note: some JSON formats have changed.

We already can *produce* dynamic derivations, but we can't refer to them
directly. Today, we can merely express building or example at the top
imperatively over time by building `foo.drv^bar.drv`, and then with a
second nix invocation doing `<result-from-first>^baz`, but this is not
declarative. The ethos of Nix of being able to write down the full plan
everything you want to do, and then execute than plan with a single
command, and for that we need the new inductive form of these types.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-08-10 00:08:32 -04:00

158 lines
4.6 KiB
C++

#include <nlohmann/json.hpp>
#include <gtest/gtest.h>
#include <rapidcheck/gtest.h>
#include "tests/path.hh"
#include "tests/libexpr.hh"
#include "tests/value/context.hh"
namespace nix {
// Test a few cases of invalid string context elements.
TEST(NixStringContextElemTest, empty_invalid) {
EXPECT_THROW(
NixStringContextElem::parse(""),
BadNixStringContextElem);
}
TEST(NixStringContextElemTest, single_bang_invalid) {
EXPECT_THROW(
NixStringContextElem::parse("!"),
BadNixStringContextElem);
}
TEST(NixStringContextElemTest, double_bang_invalid) {
EXPECT_THROW(
NixStringContextElem::parse("!!/"),
BadStorePath);
}
TEST(NixStringContextElemTest, eq_slash_invalid) {
EXPECT_THROW(
NixStringContextElem::parse("=/"),
BadStorePath);
}
TEST(NixStringContextElemTest, slash_invalid) {
EXPECT_THROW(
NixStringContextElem::parse("/"),
BadStorePath);
}
/**
* Round trip (string <-> data structure) test for
* `NixStringContextElem::Opaque`.
*/
TEST(NixStringContextElemTest, opaque) {
std::string_view opaque = "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x";
auto elem = NixStringContextElem::parse(opaque);
auto * p = std::get_if<NixStringContextElem::Opaque>(&elem);
ASSERT_TRUE(p);
ASSERT_EQ(p->path, StorePath { opaque });
ASSERT_EQ(elem.to_string(), opaque);
}
/**
* Round trip (string <-> data structure) test for
* `NixStringContextElem::DrvDeep`.
*/
TEST(NixStringContextElemTest, drvDeep) {
std::string_view drvDeep = "=g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x.drv";
auto elem = NixStringContextElem::parse(drvDeep);
auto * p = std::get_if<NixStringContextElem::DrvDeep>(&elem);
ASSERT_TRUE(p);
ASSERT_EQ(p->drvPath, StorePath { drvDeep.substr(1) });
ASSERT_EQ(elem.to_string(), drvDeep);
}
/**
* Round trip (string <-> data structure) test for a simpler
* `NixStringContextElem::Built`.
*/
TEST(NixStringContextElemTest, built_opaque) {
std::string_view built = "!foo!g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x.drv";
auto elem = NixStringContextElem::parse(built);
auto * p = std::get_if<NixStringContextElem::Built>(&elem);
ASSERT_TRUE(p);
ASSERT_EQ(p->output, "foo");
ASSERT_EQ(*p->drvPath, ((SingleDerivedPath) SingleDerivedPath::Opaque {
.path = StorePath { built.substr(5) },
}));
ASSERT_EQ(elem.to_string(), built);
}
/**
* Round trip (string <-> data structure) test for a more complex,
* inductive `NixStringContextElem::Built`.
*/
TEST(NixStringContextElemTest, built_built) {
/**
* We set these in tests rather than the regular globals so we don't have
* to worry about race conditions if the tests run concurrently.
*/
ExperimentalFeatureSettings mockXpSettings;
mockXpSettings.set("experimental-features", "dynamic-derivations ca-derivations");
std::string_view built = "!foo!bar!g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x.drv";
auto elem = NixStringContextElem::parse(built, mockXpSettings);
auto * p = std::get_if<NixStringContextElem::Built>(&elem);
ASSERT_TRUE(p);
ASSERT_EQ(p->output, "foo");
auto * drvPath = std::get_if<SingleDerivedPath::Built>(&*p->drvPath);
ASSERT_TRUE(drvPath);
ASSERT_EQ(drvPath->output, "bar");
ASSERT_EQ(*drvPath->drvPath, ((SingleDerivedPath) SingleDerivedPath::Opaque {
.path = StorePath { built.substr(9) },
}));
ASSERT_EQ(elem.to_string(), built);
}
/**
* Without the right experimental features enabled, we cannot parse a
* complex inductive string context element.
*/
TEST(NixStringContextElemTest, built_built_xp) {
ASSERT_THROW(
NixStringContextElem::parse("!foo!bar!g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x.drv"), MissingExperimentalFeature);
}
}
namespace rc {
using namespace nix;
Gen<NixStringContextElem::DrvDeep> Arbitrary<NixStringContextElem::DrvDeep>::arbitrary()
{
return gen::just(NixStringContextElem::DrvDeep {
.drvPath = *gen::arbitrary<StorePath>(),
});
}
Gen<NixStringContextElem> Arbitrary<NixStringContextElem>::arbitrary()
{
switch (*gen::inRange<uint8_t>(0, std::variant_size_v<NixStringContextElem::Raw>)) {
case 0:
return gen::just<NixStringContextElem>(*gen::arbitrary<NixStringContextElem::Opaque>());
case 1:
return gen::just<NixStringContextElem>(*gen::arbitrary<NixStringContextElem::DrvDeep>());
case 2:
return gen::just<NixStringContextElem>(*gen::arbitrary<NixStringContextElem::Built>());
default:
assert(false);
}
}
}
namespace nix {
RC_GTEST_PROP(
NixStringContextElemTest,
prop_round_rip,
(const NixStringContextElem & o))
{
RC_ASSERT(o == NixStringContextElem::parse(o.to_string()));
}
}