Avoid unwrapping when computing tab description

A bug caused the assumptions of this method to be violated. We will fix that in the next commit, but we want to be more conservative in our assumptions here going forward.

Co-Authored-By: Antonio Scandurra <me@as-cii.com>

crates/editor/src/items.rs

@@ -819,11 +819,20 @@ impl StatusItemView for CursorPosition {
 
 fn path_for_buffer<'a>(
     buffer: &ModelHandle<MultiBuffer>,
-    mut height: usize,
+    height: usize,
     include_filename: bool,
     cx: &'a AppContext,
 ) -> Option<Cow<'a, Path>> {
     let file = buffer.read(cx).as_singleton()?.read(cx).file()?;
+    path_for_file(file, height, include_filename, cx)
+}
+
+fn path_for_file<'a>(
+    file: &'a dyn language::File,
+    mut height: usize,
+    include_filename: bool,
+    cx: &'a AppContext,
+) -> Option<Cow<'a, Path>> {
     // Ensure we always render at least the filename.
     height += 1;
 
@@ -845,13 +854,82 @@ fn path_for_buffer<'a>(
         if include_filename {
             Some(full_path.into())
         } else {
-            Some(full_path.parent().unwrap().to_path_buf().into())
+            Some(full_path.parent()?.to_path_buf().into())
         }
     } else {
-        let mut path = file.path().strip_prefix(prefix).unwrap();
+        let mut path = file.path().strip_prefix(prefix).ok()?;
         if !include_filename {
-            path = path.parent().unwrap();
+            path = path.parent()?;
         }
         Some(path.into())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use gpui::MutableAppContext;
+    use std::{
+        path::{Path, PathBuf},
+        sync::Arc,
+    };
+
+    #[gpui::test]
+    fn test_path_for_file(cx: &mut MutableAppContext) {
+        let file = TestFile {
+            path: Path::new("").into(),
+            full_path: PathBuf::from(""),
+        };
+        assert_eq!(path_for_file(&file, 0, false, cx), None);
+    }
+
+    struct TestFile {
+        path: Arc<Path>,
+        full_path: PathBuf,
+    }
+
+    impl language::File for TestFile {
+        fn path(&self) -> &Arc<Path> {
+            &self.path
+        }
+
+        fn full_path(&self, _: &gpui::AppContext) -> PathBuf {
+            self.full_path.clone()
+        }
+
+        fn as_local(&self) -> Option<&dyn language::LocalFile> {
+            todo!()
+        }
+
+        fn mtime(&self) -> std::time::SystemTime {
+            todo!()
+        }
+
+        fn file_name<'a>(&'a self, _: &'a gpui::AppContext) -> &'a std::ffi::OsStr {
+            todo!()
+        }
+
+        fn is_deleted(&self) -> bool {
+            todo!()
+        }
+
+        fn save(
+            &self,
+            _: u64,
+            _: language::Rope,
+            _: clock::Global,
+            _: project::LineEnding,
+            _: &mut MutableAppContext,
+        ) -> gpui::Task<anyhow::Result<(clock::Global, String, std::time::SystemTime)>> {
+            todo!()
+        }
+
+        fn as_any(&self) -> &dyn std::any::Any {
+            todo!()
+        }
+
+        fn to_proto(&self) -> rpc::proto::File {
+            todo!()
+        }
+    }
+}