fix: Get the file stem rather than file name for the UUID (#6284)

Oops. Stupid mistake, behavior that should have had a test but didn't.

Fixes #6270.

wal/src/lib.rs

@@ -233,8 +233,12 @@ impl Wal {
                 .context(UnableToReadFileMetadataSnafu)?;
             if metadata.is_file() {
                 let child_path = child.path();
-                let filename = child_path.file_name().unwrap();
-                let filename = filename.to_str().unwrap();
+                let filename = child_path
+                    .file_stem()
+                    .expect("WAL files created by IOx should have a file stem");
+                let filename = filename
+                    .to_str()
+                    .expect("WAL files created by IOx should be named with valid UTF-8");
                 let id = Uuid::parse_str(filename)
                     .context(InvalidUuidSnafu { filename })?
                     .into();

wal/tests/end_to_end.rs

@@ -77,6 +77,37 @@ async fn crud() {
     );
 }
 
+#[tokio::test]
+async fn replay() {
+    let dir = test_helpers::tmp_dir().unwrap();
+
+    // Create a WAL with an entry then drop the WAL
+    {
+        let wal = wal::Wal::new(dir.path()).await.unwrap();
+        let open = wal.write_handle().await;
+        let op = arbitrary_sequenced_wal_op(42);
+        open.write_op(op).await.unwrap();
+        let wal_rotator = wal.rotation_handle().await;
+        wal_rotator.rotate().await.unwrap();
+    }
+
+    // Create a new WAL instance with the same directory to replay from the files
+    let wal = wal::Wal::new(dir.path()).await.unwrap();
+    let wal_reader = wal.read_handle();
+
+    // There's one closed segment
+    let closed = wal_reader.closed_segments().await;
+    let closed_segment_ids: Vec<_> = closed.iter().map(|c| c.id()).collect();
+
+    // Can read the written entries from the closed segment
+    let mut reader = wal_reader
+        .reader_for_segment(closed_segment_ids[0])
+        .await
+        .unwrap();
+    let op = reader.next_ops().await.unwrap().unwrap();
+    assert_eq!(op.sequence_number.get(), 42);
+}
+
 fn arbitrary_sequenced_wal_op(sequence_number: u64) -> SequencedWalOp {
     let w = test_data("m1,t=foo v=1i 1");
     SequencedWalOp {