feat(tvix/store): add rstest-based PathInfoService tests r/7788

This introduces rstest-based tests. We also add fixtures for creating
some BlobService / DirectoryService out of thin air.
To test a PathInfoService, we don't really care too much about its
internal storage - ensuring they work is up to the castore tests.

Change-Id: Ia62af076ef9c9fbfcf8b020a781454ad299d972e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11272
Tested-by: BuildkiteCI
Reviewed-by: Connor Brewster <cbrewster@hey.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/tvix/store/src/pathinfoservice/tests/utils.rs b/tvix/store/src/pathinfoservice/tests/utils.rs
new file mode 100644
index 0000000000..31ec57aade
--- /dev/null
+++ b/tvix/store/src/pathinfoservice/tests/utils.rs
@@ -0,0 +1,60 @@
+use std::sync::Arc;
+
+use tonic::transport::{Endpoint, Server, Uri};
+
+use crate::{
+    pathinfoservice::{GRPCPathInfoService, MemoryPathInfoService, PathInfoService},
+    proto::{
+        path_info_service_client::PathInfoServiceClient,
+        path_info_service_server::PathInfoServiceServer, GRPCPathInfoServiceWrapper,
+    },
+    tests::fixtures::{blob_service, directory_service},
+};
+
+/// Constructs and returns a gRPC PathInfoService.
+/// We also return memory-based {Blob,Directory}Service,
+/// as the consumer of this function accepts a 3-tuple.
+pub async fn make_grpc_path_info_service_client() -> super::BSDSPS {
+    let (left, right) = tokio::io::duplex(64);
+
+    let blob_service = blob_service();
+    let directory_service = directory_service();
+
+    // spin up a server, which will only connect once, to the left side.
+    tokio::spawn({
+        let blob_service = blob_service.clone();
+        let directory_service = directory_service.clone();
+        async move {
+            let path_info_service: Arc<dyn PathInfoService> =
+                Arc::from(MemoryPathInfoService::new(blob_service, directory_service));
+
+            // spin up a new DirectoryService
+            let mut server = Server::builder();
+            let router = server.add_service(PathInfoServiceServer::new(
+                GRPCPathInfoServiceWrapper::new(path_info_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);
+
+    let path_info_service = Box::new(GRPCPathInfoService::from_client(
+        PathInfoServiceClient::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(),
+        ),
+    ));
+
+    (blob_service, directory_service, path_info_service)
+}