SERVER-57810 Enable setting mock filenames for devnull KVEngine backup cursor

2 files changed, 11 insertions, 4 deletions

diff --git a/src/mongo/db/storage/devnull/devnull_kv_engine.cpp b/src/mongo/db/storage/devnull/devnull_kv_engine.cpp
index f56087b7a95..144b289e27e 100644
--- a/src/mongo/db/storage/devnull/devnull_kv_engine.cpp
+++ b/src/mongo/db/storage/devnull/devnull_kv_engine.cpp
@@ -261,9 +261,9 @@ namespace {
 class StreamingCursorImpl : public StorageEngine::StreamingCursor {
 public:
     StreamingCursorImpl() = delete;
-    StreamingCursorImpl(StorageEngine::BackupOptions options)
-        : StorageEngine::StreamingCursor(options) {
-        _backupBlocks = {{"filename.wt"}};
+    StreamingCursorImpl(StorageEngine::BackupOptions options,
+                        std::vector<StorageEngine::BackupBlock> backupBlocks)
+        : StorageEngine::StreamingCursor(options), _backupBlocks(std::move(backupBlocks)) {
         _exhaustCursor = false;
     };
 
@@ -291,7 +291,7 @@ private:
 
 StatusWith<std::unique_ptr<StorageEngine::StreamingCursor>> DevNullKVEngine::beginNonBlockingBackup(
     OperationContext* opCtx, const StorageEngine::BackupOptions& options) {
-    return std::make_unique<StreamingCursorImpl>(options);
+    return std::make_unique<StreamingCursorImpl>(options, _mockBackupBlocks);
 }
 
 StatusWith<std::vector<std::string>> DevNullKVEngine::extendBackupCursor(OperationContext* opCtx) {
diff --git a/src/mongo/db/storage/devnull/devnull_kv_engine.h b/src/mongo/db/storage/devnull/devnull_kv_engine.h
index 97e414852ea..e3f3f2ae3f3 100644
--- a/src/mongo/db/storage/devnull/devnull_kv_engine.h
+++ b/src/mongo/db/storage/devnull/devnull_kv_engine.h
@@ -160,9 +160,16 @@ public:
 
     virtual void setPinnedOplogTimestamp(const Timestamp& pinnedTimestamp) {}
 
+    // This sets the results of the backup cursor for unit tests.
+    void setBackupBlocks_forTest(std::vector<StorageEngine::BackupBlock> newBackupBlocks) {
+        _mockBackupBlocks = newBackupBlocks;
+    }
+
 private:
     std::shared_ptr<void> _catalogInfo;
 
     int _cachePressureForTest;
+
+    std::vector<StorageEngine::BackupBlock> _mockBackupBlocks = {{"filename.wt"}};
 };
 }  // namespace mongo