dont overwrite memfies

1 files changed, 12 insertions, 0 deletions

diff --git a/crates/ra_vfs/tests/vfs.rs b/crates/ra_vfs/tests/vfs.rs
index 357e1c775..545e1dbdd 100644
--- a/crates/ra_vfs/tests/vfs.rs
+++ b/crates/ra_vfs/tests/vfs.rs
@@ -165,6 +165,18 @@ fn test_vfs_works() -> std::io::Result<()> {
         assert_eq!(path, "sub1/sub2/new1.rs")
     );
 
+    {
+        vfs.add_file_overlay(&dir.path().join("a/memfile.rs"), "memfile".to_string());
+        assert_match!(
+            vfs.commit_changes().as_slice(),
+            [VfsChange::AddFile { text, .. }],
+            assert_eq!(text.as_str(), "memfile")
+        );
+        fs::write(&dir.path().join("a/memfile.rs"), "ignore me").unwrap();
+        process_tasks(&mut vfs, 1);
+        assert_match!(vfs.commit_changes().as_slice(), []);
+    }
+
     // should be ignored
     fs::create_dir_all(dir.path().join("a/target")).unwrap();
     fs::write(&dir.path().join("a/target/new.rs"), "ignore me").unwrap();