chore: clean up codebase (#19)

Reviewed-on: #19

crates/workspace/src/views/tree.rs

@@ -0,0 +1,153 @@
+use std::collections::HashMap;
+use std::path::PathBuf;
+
+use gpui_component::tree::TreeItem;
+
+pub(crate) struct TreeItemSeed {
+    /// Path of the node, relative to the worktree root.
+    pub(crate) id: String,
+    pub(crate) label: String,
+    pub(crate) children: Vec<TreeItemSeed>,
+}
+
+pub(crate) fn tree_items(seeds: Vec<TreeItemSeed>, expand_folders: bool) -> Vec<TreeItem> {
+    fn convert(seed: TreeItemSeed, expand_folders: bool) -> TreeItem {
+        let mut item = TreeItem::new(seed.id, seed.label);
+        if expand_folders && !seed.children.is_empty() {
+            item = item.expanded(true);
+        }
+        item.children = seed
+            .children
+            .into_iter()
+            .map(|seed| convert(seed, expand_folders))
+            .collect();
+        item
+    }
+
+    seeds
+        .into_iter()
+        .map(|seed| convert(seed, expand_folders))
+        .collect()
+}
+
+/// Build nested tree items from a flat entry list sorted dirs-first.
+pub(crate) fn build_tree_items(entries: &[PathBuf]) -> Vec<TreeItemSeed> {
+    // Node indices by full path, so parents resolve in constant time while inserting.
+    let mut index: HashMap<String, usize> = HashMap::new();
+    let mut nodes: Vec<(String, String, Vec<usize>)> = Vec::new();
+    let mut roots: Vec<usize> = Vec::new();
+
+    for entry in entries {
+        let mut parent: Option<usize> = None;
+        let mut path = String::new();
+        for part in entry.components() {
+            let label = part.as_os_str().to_string_lossy().into_owned();
+            path = if path.is_empty() {
+                label.clone()
+            } else {
+                format!("{path}/{label}")
+            };
+            let ix = *index.entry(path.clone()).or_insert_with(|| {
+                let ix = nodes.len();
+                nodes.push((path.clone(), label.clone(), Vec::new()));
+                match parent {
+                    Some(parent) => nodes[parent].2.push(ix),
+                    None => roots.push(ix),
+                }
+                ix
+            });
+            parent = Some(ix);
+        }
+    }
+
+    fn assemble(ix: usize, nodes: &[(String, String, Vec<usize>)]) -> TreeItemSeed {
+        let (id, label, children) = &nodes[ix];
+        TreeItemSeed {
+            id: id.clone(),
+            label: label.clone(),
+            children: children
+                .iter()
+                .map(|child| assemble(*child, nodes))
+                .collect(),
+        }
+    }
+
+    roots.iter().map(|root| assemble(*root, &nodes)).collect()
+}
+
+/// Sorted relative paths of a worktree snapshot.
+///
+/// Compared against the `worktree_paths` of a repository panel to skip
+/// rebuilding the explorer when a refresh left the worktree unchanged.
+pub(crate) fn sorted_worktree_paths(entries: &[PathBuf]) -> Vec<String> {
+    let mut paths: Vec<String> = entries
+        .iter()
+        .map(|path| path.to_string_lossy().into_owned())
+        .collect();
+    paths.sort();
+    paths
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn builds_nested_tree_from_flat_entries() {
+        let entries = vec![
+            PathBuf::from("src"),
+            PathBuf::from("src/lib.rs"),
+            PathBuf::from("README.md"),
+            PathBuf::from("docs/guide.md"),
+        ];
+
+        let items = build_tree_items(&entries);
+
+        // Input order is preserved, dirs-first as produced by worktree_entries.
+        assert_eq!(items.len(), 3);
+        assert_eq!(items[0].label, "src");
+        assert_eq!(items[0].id, "src");
+        assert_eq!(items[0].children.len(), 1);
+        assert_eq!(items[0].children[0].label, "lib.rs");
+        assert_eq!(items[0].children[0].id, "src/lib.rs");
+
+        assert_eq!(items[1].label, "README.md");
+        assert_eq!(items[1].id, "README.md");
+
+        assert_eq!(items[2].label, "docs");
+        assert_eq!(items[2].children[0].label, "guide.md");
+        assert_eq!(items[2].children[0].id, "docs/guide.md");
+    }
+
+    #[test]
+    fn tree_builder_handles_deep_nesting() {
+        let entries = vec![
+            PathBuf::from("a"),
+            PathBuf::from("a/b"),
+            PathBuf::from("a/b/c.txt"),
+        ];
+
+        let items = build_tree_items(&entries);
+        assert_eq!(items.len(), 1);
+        assert_eq!(items[0].children[0].id, "a/b");
+        assert_eq!(items[0].children[0].children[0].id, "a/b/c.txt");
+    }
+
+    #[test]
+    fn tree_builder_merges_shared_prefixes() {
+        // File children of a directory arrive after other directories' entries.
+        // The worktree list is dirs-first globally.
+        // The shared prefix must still resolve to one node.
+        let entries = vec![
+            PathBuf::from("a/x.txt"),
+            PathBuf::from("b/y.txt"),
+            PathBuf::from("a/z.txt"),
+        ];
+
+        let items = build_tree_items(&entries);
+        assert_eq!(items.len(), 2);
+        assert_eq!(items[0].label, "a");
+        assert_eq!(items[0].children.len(), 2);
+        assert_eq!(items[1].label, "b");
+    }
+}