feat(tvix/castore): add rstest-based DirectoryService tests r/7777

This creates test scenarios (using the DirectoryService trait) that we
want all DirectoryService implementations to pass.

Some of these tests are ported from proto::tests::grpc_directoryservice,
which tested this on the gRPC interface (rather than the trait),
some others ensure certain behaviour for which we only recently
introduced general checking logic (through ClosureValidator).

We also borrow some code related to setting up a gRPC DirectoryService
client (connecting to a server exposing a in-memory DiretoryService)
from castore::utils, this will be deleted once it's all ported over.

Change-Id: I6810215a76101f908e2aaecafa803c70d85bc552
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11247
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Tested-by: BuildkiteCI

5 files changed, 275 insertions, 1 deletions

diff --git a/tvix/castore/src/directoryservice/mod.rs b/tvix/castore/src/directoryservice/mod.rs
index 523c61d056cc..997b47e502e4 100644
--- a/tvix/castore/src/directoryservice/mod.rs
+++ b/tvix/castore/src/directoryservice/mod.rs
@@ -8,6 +8,8 @@ mod grpc;
 mod memory;
 mod simple_putter;
 mod sled;
+#[cfg(test)]
+mod tests;
 mod traverse;
 mod utils;
 
diff --git a/tvix/castore/src/directoryservice/tests/mod.rs b/tvix/castore/src/directoryservice/tests/mod.rs
new file mode 100644
index 000000000000..5eb2d1919e80
--- /dev/null
+++ b/tvix/castore/src/directoryservice/tests/mod.rs
@@ -0,0 +1,221 @@
+//! This contains test scenarios that a given [DirectoryService] needs to pass.
+//! We use [rstest] and [rstest_reuse] to provide all services we want to test
+//! against, and then apply this template to all test functions.
+
+use futures::StreamExt;
+use rstest::*;
+use rstest_reuse::{self, *};
+
+use super::DirectoryService;
+use crate::directoryservice;
+use crate::{
+    fixtures::{DIRECTORY_A, DIRECTORY_B, DIRECTORY_C},
+    proto::{self, Directory},
+};
+
+mod utils;
+use self::utils::make_grpc_directory_service_client;
+
+/// This produces a template, which will be applied to all individual test functions.
+/// See https://github.com/la10736/rstest/issues/130#issuecomment-968864832
+#[template]
+#[rstest]
+#[case::memory(directoryservice::from_addr("memory://").await.unwrap())]
+#[case::grpc(make_grpc_directory_service_client().await)]
+#[case::sled(directoryservice::from_addr("sled://").await.unwrap())]
+pub fn directory_services(#[case] directory_service: impl DirectoryService) {}
+
+/// Ensures asking for a directory that doesn't exist returns a Ok(None).
+#[apply(directory_services)]
+#[tokio::test]
+async fn test_non_exist(directory_service: impl DirectoryService) {
+    let resp = directory_service.get(&DIRECTORY_A.digest()).await;
+    assert!(resp.unwrap().is_none())
+}
+
+/// Putting a single directory into the store, and then getting it out both via
+/// `.get[_recursive]` should work.
+#[apply(directory_services)]
+#[tokio::test]
+async fn put_get(directory_service: impl DirectoryService) {
+    // Insert a Directory.
+    let digest = directory_service.put(DIRECTORY_A.clone()).await.unwrap();
+    assert_eq!(DIRECTORY_A.digest(), digest, "returned digest must match");
+
+    // single get
+    assert_eq!(
+        Some(DIRECTORY_A.clone()),
+        directory_service.get(&DIRECTORY_A.digest()).await.unwrap()
+    );
+
+    // recursive get
+    assert_eq!(
+        vec![Ok(DIRECTORY_A.clone())],
+        directory_service
+            .get_recursive(&DIRECTORY_A.digest())
+            .collect::<Vec<_>>()
+            .await
+    );
+}
+
+/// Putting a directory closure should work, and it should be possible to get
+/// back the root node both via .get[_recursive]. We don't check `.get` for the
+/// leaf node is possible, as it's Ok for stores to not support that.
+#[apply(directory_services)]
+#[tokio::test]
+async fn put_get_multiple_success(directory_service: impl DirectoryService) {
+    // Insert a Directory closure.
+    let mut handle = directory_service.put_multiple_start();
+    handle.put(DIRECTORY_A.clone()).await.unwrap();
+    handle.put(DIRECTORY_C.clone()).await.unwrap();
+    let root_digest = handle.close().await.unwrap();
+    assert_eq!(
+        DIRECTORY_C.digest(),
+        root_digest,
+        "root digest should match"
+    );
+
+    // Get the root node.
+    assert_eq!(
+        Some(DIRECTORY_C.clone()),
+        directory_service.get(&DIRECTORY_C.digest()).await.unwrap()
+    );
+
+    // Get the closure. Ensure it's sent from the root to the leaves.
+    assert_eq!(
+        vec![Ok(DIRECTORY_C.clone()), Ok(DIRECTORY_A.clone())],
+        directory_service
+            .get_recursive(&DIRECTORY_C.digest())
+            .collect::<Vec<_>>()
+            .await
+    )
+}
+
+/// Puts a directory closure, but simulates a dumb client not deduplicating
+/// its list. Ensure we still only get back a deduplicated list.
+#[apply(directory_services)]
+#[tokio::test]
+async fn put_get_multiple_dedup(directory_service: impl DirectoryService) {
+    // Insert a Directory closure.
+    let mut handle = directory_service.put_multiple_start();
+    handle.put(DIRECTORY_A.clone()).await.unwrap();
+    handle.put(DIRECTORY_A.clone()).await.unwrap();
+    handle.put(DIRECTORY_C.clone()).await.unwrap();
+    let root_digest = handle.close().await.unwrap();
+    assert_eq!(
+        DIRECTORY_C.digest(),
+        root_digest,
+        "root digest should match"
+    );
+
+    // Ensure the returned closure only contains `DIRECTORY_A` once.
+    assert_eq!(
+        vec![Ok(DIRECTORY_C.clone()), Ok(DIRECTORY_A.clone())],
+        directory_service
+            .get_recursive(&DIRECTORY_C.digest())
+            .collect::<Vec<_>>()
+            .await
+    )
+}
+
+/// Uploading A, then C (referring to A twice), then B (itself referring to A) should fail during close,
+/// as B itself would be left unconnected.
+#[apply(directory_services)]
+#[tokio::test]
+async fn upload_reject_unconnected(directory_service: impl DirectoryService) {
+    let mut handle = directory_service.put_multiple_start();
+
+    handle.put(DIRECTORY_A.clone()).await.unwrap();
+    handle.put(DIRECTORY_C.clone()).await.unwrap();
+    handle.put(DIRECTORY_B.clone()).await.unwrap();
+
+    assert!(
+        handle.close().await.is_err(),
+        "closing handle should fail, as B would be left unconnected"
+    );
+}
+
+/// Uploading a directory that refers to another directory not yet uploaded
+/// should fail.
+#[apply(directory_services)]
+#[tokio::test]
+async fn upload_reject_dangling_pointer(directory_service: impl DirectoryService) {
+    let mut handle = directory_service.put_multiple_start();
+
+    // We insert DIRECTORY_A on its own, to ensure the check runs for the
+    // individual put_multiple session, not across the global DirectoryService
+    // contents.
+    directory_service.put(DIRECTORY_A.clone()).await.unwrap();
+
+    // DIRECTORY_B refers to DIRECTORY_A, which is not uploaded with this handle.
+    if handle.put(DIRECTORY_B.clone()).await.is_ok() {
+        assert!(
+            handle.close().await.is_err(),
+            "when succeeding put, close must fail"
+        )
+    }
+}
+
+/// Try uploading a Directory failing its internal validation, ensure it gets
+/// rejected.
+#[apply(directory_services)]
+#[tokio::test]
+async fn upload_reject_failing_validation(directory_service: impl DirectoryService) {
+    let broken_directory = Directory {
+        symlinks: vec![proto::SymlinkNode {
+            name: "".into(), // wrong!
+            target: "doesntmatter".into(),
+        }],
+        ..Default::default()
+    };
+    assert!(broken_directory.validate().is_err());
+
+    // Try to upload via single upload.
+    assert!(
+        directory_service
+            .put(broken_directory.clone())
+            .await
+            .is_err(),
+        "single upload must fail"
+    );
+
+    // Try to upload via put_multiple. We're a bit more permissive here, the
+    // intermediate .put() might succeed, but then the close MUST fail.
+    let mut handle = directory_service.put_multiple_start();
+    if handle.put(broken_directory).await.is_ok() {
+        assert!(
+            handle.close().await.is_err(),
+            "when succeeding put, close must fail"
+        )
+    }
+}
+
+/// Try uploading a Directory that refers to a previously-uploaded directory.
+/// Both pass their isolated validation, but the size field in the parent is wrong.
+/// This should be rejected.
+#[apply(directory_services)]
+#[tokio::test]
+async fn upload_reject_wrong_size(directory_service: impl DirectoryService) {
+    let wrong_parent_directory = Directory {
+        directories: vec![proto::DirectoryNode {
+            name: "foo".into(),
+            digest: DIRECTORY_A.digest().into(),
+            size: DIRECTORY_A.size() + 42, // wrong!
+        }],
+        ..Default::default()
+    };
+
+    // Make sure isolated validation itself is ok
+    assert!(wrong_parent_directory.validate().is_ok());
+
+    // Now upload both. Ensure it either fails during the second put, or during
+    // the close.
+    let mut handle = directory_service.put_multiple_start();
+    handle.put(DIRECTORY_A.clone()).await.unwrap();
+    if handle.put(wrong_parent_directory).await.is_ok() {
+        assert!(
+            handle.close().await.is_err(),
+            "when second put succeeds, close must fail"
+        )
+    }
+}
diff --git a/tvix/castore/src/directoryservice/tests/utils.rs b/tvix/castore/src/directoryservice/tests/utils.rs
new file mode 100644
index 000000000000..72a3ff754d19
--- /dev/null
+++ b/tvix/castore/src/directoryservice/tests/utils.rs
@@ -0,0 +1,45 @@
+use crate::directoryservice::{DirectoryService, GRPCDirectoryService};
+use crate::proto::directory_service_client::DirectoryServiceClient;
+use crate::proto::GRPCDirectoryServiceWrapper;
+use crate::{
+    directoryservice::MemoryDirectoryService,
+    proto::directory_service_server::DirectoryServiceServer,
+};
+use tonic::transport::{Endpoint, Server, Uri};
+
+/// Constructs and returns a gRPC DirectoryService.
+/// The server part is a [MemoryDirectoryService], exposed via the
+/// [GRPCDirectoryServiceWrapper], and connected through a DuplexStream.
+pub async fn make_grpc_directory_service_client() -> Box<dyn DirectoryService> {
+    let (left, right) = tokio::io::duplex(64);
+
+    // spin up a server, which will only connect once, to the left side.
+    tokio::spawn(async {
+        let directory_service =
+            Box::<MemoryDirectoryService>::default() as Box<dyn DirectoryService>;
+
+        let mut server = Server::builder();
+        let router = server.add_service(DirectoryServiceServer::new(
+            GRPCDirectoryServiceWrapper::new(directory_service),
+        ));
+
+        router
+            .serve_with_incoming(tokio_stream::once(Ok::<_, std::io::Error>(left)))
+            .await
+    });
+
+    // Create a client, connecting to the right side. The URI is unused.
+    let mut maybe_right = Some(right);
+    Box::new(GRPCDirectoryService::from_client(
+        DirectoryServiceClient::new(
+            Endpoint::try_from("http://[::]:50051")
+                .unwrap()
+                .connect_with_connector(tower::service_fn(move |_: Uri| {
+                    let right = maybe_right.take().unwrap();
+                    async move { Ok::<_, std::io::Error>(right) }
+                }))
+                .await
+                .unwrap(),
+        ),
+    ))
+}
diff --git a/tvix/castore/src/errors.rs b/tvix/castore/src/errors.rs
index 1b3ae4d1c862..e807a19b9e61 100644
--- a/tvix/castore/src/errors.rs
+++ b/tvix/castore/src/errors.rs
@@ -4,7 +4,7 @@ use tokio::task::JoinError;
 use tonic::Status;
 
 /// Errors related to communication with the store.
-#[derive(Debug, Error)]
+#[derive(Debug, Error, PartialEq)]
 pub enum Error {
     #[error("invalid request: {0}")]
     InvalidRequest(String),
diff --git a/tvix/castore/src/lib.rs b/tvix/castore/src/lib.rs
index dec7684b4c57..1ce092135b83 100644
--- a/tvix/castore/src/lib.rs
+++ b/tvix/castore/src/lib.rs
@@ -20,3 +20,9 @@ pub use hashing_reader::{B3HashingReader, HashingReader};
 
 #[cfg(test)]
 mod tests;
+
+// That's what the rstest_reuse README asks us do, and fails about being unable
+// to find rstest_reuse in crate root.
+#[cfg(test)]
+#[allow(clippy::single_component_path_imports)]
+use rstest_reuse;