feat(3p/nix): add tests for BinaryCacheStore r/1596

These tests are in preparation for factoring the Store away from libutil's Callback to absl::StatusOr.
They use the newly added MockBinaryCacheStore.

Updates: #25

Change-Id: I30c207589ec38254806ebc9a983f35668e353ae9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1595
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>

1 files changed, 97 insertions, 0 deletions

diff --git a/third_party/nix/src/tests/store_tests.cc b/third_party/nix/src/tests/store_tests.cc
new file mode 100644
index 000000000000..1aea33bfd18b
--- /dev/null
+++ b/third_party/nix/src/tests/store_tests.cc
@@ -0,0 +1,97 @@
+#include <filesystem>
+
+#include <absl/container/btree_map.h>
+#include <absl/container/flat_hash_map.h>
+#include <absl/strings/escaping.h>
+#include <glog/logging.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <sys/random.h>
+
+#include "libstore/binary-cache-store.hh"
+#include "libstore/mock-binary-cache-store.hh"
+
+using ::testing::HasSubstr;
+
+namespace nix {
+
+MakeError(InjectedError, Error);
+
+class StoreTest : public ::testing::Test {
+ public:
+  static void SetUpTestSuite() {
+    google::InitGoogleLogging("--logtostderr=false");
+  }
+};
+
+class BinaryCacheStoreTest : public StoreTest {};
+
+constexpr absl::string_view kXZHeader = "7zXZ";
+
+constexpr absl::string_view kRootFileName = "myRootFile";
+constexpr absl::string_view kDep1FileName = "dep1";
+constexpr absl::string_view kDep1FileContents = "==dep1 contents==";
+constexpr absl::string_view kDep1NarCache =
+    "nar/0hfdc95cy6mxi4c15pp0frdf97r7yvd8c141qzvpms2f8x17p2ig.nar.xz";
+constexpr absl::string_view kBogusPath =
+    "/nix/store/g1ghizdg18k0d00000000000000z3v32-doesNotExist";
+
+struct TestTree {
+  Path rootPath;
+  Path dep1Path;
+};
+
+TestTree AddTestTreeToStore(Store& store) {
+  TestTree results;
+  results.rootPath =
+      store.addTextToStore(std::string(kRootFileName), "1", PathSet());
+
+  PathSet onlyRoot;
+  onlyRoot.insert(results.rootPath);
+  results.dep1Path = store.addTextToStore(
+      std::string(kDep1FileName), std::string(kDep1FileContents), onlyRoot);
+
+  return results;
+}
+
+TEST_F(BinaryCacheStoreTest, BasicStorage) {
+  MockBinaryCacheStore::Params params;
+  MockBinaryCacheStore store(params);
+
+  store.init();
+
+  auto tree = AddTestTreeToStore(store);
+
+  EXPECT_TRUE(store.isValidPath(tree.rootPath));
+  EXPECT_TRUE(store.isValidPath(tree.dep1Path));
+
+  StringSink sink;
+  store.narFromPath(tree.dep1Path, sink);
+  EXPECT_THAT(*sink.s, HasSubstr(kDep1FileContents));
+
+  EXPECT_THAT(*store.BinaryCacheStore::getFile(Path(kDep1NarCache)),
+              HasSubstr(kXZHeader));
+}
+
+TEST_F(BinaryCacheStoreTest, BasicErrors) {
+  MockBinaryCacheStore::Params params;
+  MockBinaryCacheStore store(params);
+
+  store.init();
+
+  auto tree = AddTestTreeToStore(store);
+  store.PrepareErrorInjection(std::string(kDep1NarCache),
+                              []() { throw InjectedError("injected"); });
+
+  {
+    StringSink sink;
+    EXPECT_THROW(store.narFromPath(tree.dep1Path, sink), InjectedError);
+  }
+  {
+    StringSink sink;
+    EXPECT_THROW(store.narFromPath(std::string(kBogusPath), sink),
+                 NoSuchBinaryCacheFile);
+  }
+}
+
+}  // namespace nix