2 files changed, 96 insertions, 9 deletions

diff --git a/src/libstore/tests/derived-path.cc b/src/libstore/tests/derived-path.cc
index 160443ec1..d6549f66f 100644
--- a/src/libstore/tests/derived-path.cc
+++ b/src/libstore/tests/derived-path.cc
@@ -17,14 +17,34 @@ Gen<DerivedPath::Opaque> Arbitrary<DerivedPath::Opaque>::arbitrary()
     });
 }
 
+Gen<SingleDerivedPath::Built> Arbitrary<SingleDerivedPath::Built>::arbitrary()
+{
+    return gen::just(SingleDerivedPath::Built {
+        .drvPath = make_ref<SingleDerivedPath>(*gen::arbitrary<SingleDerivedPath>()),
+        .output = (*gen::arbitrary<StorePathName>()).name,
+    });
+}
+
 Gen<DerivedPath::Built> Arbitrary<DerivedPath::Built>::arbitrary()
 {
     return gen::just(DerivedPath::Built {
-        .drvPath = *gen::arbitrary<StorePath>(),
+        .drvPath = make_ref<SingleDerivedPath>(*gen::arbitrary<SingleDerivedPath>()),
         .outputs = *gen::arbitrary<OutputsSpec>(),
     });
 }
 
+Gen<SingleDerivedPath> Arbitrary<SingleDerivedPath>::arbitrary()
+{
+    switch (*gen::inRange<uint8_t>(0, std::variant_size_v<SingleDerivedPath::Raw>)) {
+    case 0:
+        return gen::just<SingleDerivedPath>(*gen::arbitrary<SingleDerivedPath::Opaque>());
+    case 1:
+        return gen::just<SingleDerivedPath>(*gen::arbitrary<SingleDerivedPath::Built>());
+    default:
+        assert(false);
+    }
+}
+
 Gen<DerivedPath> Arbitrary<DerivedPath>::arbitrary()
 {
     switch (*gen::inRange<uint8_t>(0, std::variant_size_v<DerivedPath::Raw>)) {
@@ -45,12 +65,69 @@ class DerivedPathTest : public LibStoreTest
 {
 };
 
-// FIXME: `RC_GTEST_FIXTURE_PROP` isn't calling `SetUpTestSuite` because it is
-// no a real fixture.
-//
-// See https://github.com/emil-e/rapidcheck/blob/master/doc/gtest.md#rc_gtest_fixture_propfixture-name-args
-TEST_F(DerivedPathTest, force_init)
-{
+/**
+ * Round trip (string <-> data structure) test for
+ * `DerivedPath::Opaque`.
+ */
+TEST_F(DerivedPathTest, opaque) {
+    std::string_view opaque = "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x";
+    auto elem = DerivedPath::parse(*store, opaque);
+    auto * p = std::get_if<DerivedPath::Opaque>(&elem);
+    ASSERT_TRUE(p);
+    ASSERT_EQ(p->path, store->parseStorePath(opaque));
+    ASSERT_EQ(elem.to_string(*store), opaque);
+}
+
+/**
+ * Round trip (string <-> data structure) test for a simpler
+ * `DerivedPath::Built`.
+ */
+TEST_F(DerivedPathTest, built_opaque) {
+    std::string_view built = "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x.drv^bar,foo";
+    auto elem = DerivedPath::parse(*store, built);
+    auto * p = std::get_if<DerivedPath::Built>(&elem);
+    ASSERT_TRUE(p);
+    ASSERT_EQ(p->outputs, ((OutputsSpec) OutputsSpec::Names { "foo", "bar" }));
+    ASSERT_EQ(*p->drvPath, ((SingleDerivedPath) SingleDerivedPath::Opaque {
+        .path = store->parseStorePath(built.substr(0, 49)),
+    }));
+    ASSERT_EQ(elem.to_string(*store), built);
+}
+
+/**
+ * Round trip (string <-> data structure) test for a more complex,
+ * inductive `DerivedPath::Built`.
+ */
+TEST_F(DerivedPathTest, 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 = "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x.drv^foo^bar,baz";
+    auto elem = DerivedPath::parse(*store, built, mockXpSettings);
+    auto * p = std::get_if<DerivedPath::Built>(&elem);
+    ASSERT_TRUE(p);
+    ASSERT_EQ(p->outputs, ((OutputsSpec) OutputsSpec::Names { "bar", "baz" }));
+    auto * drvPath = std::get_if<SingleDerivedPath::Built>(&*p->drvPath);
+    ASSERT_TRUE(drvPath);
+    ASSERT_EQ(drvPath->output, "foo");
+    ASSERT_EQ(*drvPath->drvPath, ((SingleDerivedPath) SingleDerivedPath::Opaque {
+        .path = store->parseStorePath(built.substr(0, 49)),
+    }));
+    ASSERT_EQ(elem.to_string(*store), built);
+}
+
+/**
+ * Without the right experimental features enabled, we cannot parse a
+ * complex inductive derived path.
+ */
+TEST_F(DerivedPathTest, built_built_xp) {
+    ASSERT_THROW(
+        DerivedPath::parse(*store, "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x.drv^foo^bar,baz"),
+        MissingExperimentalFeature);
 }
 
 RC_GTEST_FIXTURE_PROP(
diff --git a/src/libstore/tests/derived-path.hh b/src/libstore/tests/derived-path.hh
index 506f3ccb1..98d61f228 100644
--- a/src/libstore/tests/derived-path.hh
+++ b/src/libstore/tests/derived-path.hh
@@ -12,8 +12,18 @@ namespace rc {
 using namespace nix;
 
 template<>
-struct Arbitrary<DerivedPath::Opaque> {
-    static Gen<DerivedPath::Opaque> arbitrary();
+struct Arbitrary<SingleDerivedPath::Opaque> {
+    static Gen<SingleDerivedPath::Opaque> arbitrary();
+};
+
+template<>
+struct Arbitrary<SingleDerivedPath::Built> {
+    static Gen<SingleDerivedPath::Built> arbitrary();
+};
+
+template<>
+struct Arbitrary<SingleDerivedPath> {
+    static Gen<SingleDerivedPath> arbitrary();
 };
 
 template<>