refactor: implement Index<LeafExecutionPath> for ExecutionGraph

Add Index<&LeafExecutionPath> for ExecutionGraph with Output = LeafExecutionKind,
providing direct indexing into nested execution graphs to retrieve leaf execution kinds.

- Extract shared graph traversal into LeafExecutionPath::resolve_item()
- Remove Option from display fields in labeled reporter (was unreachable dead code)
- Add explicit Index<NodeIndex<Ix>> on AcyclicGraph to prevent shadowing through Deref

Author: branchseer

crates/vite_task/src/session/reporter/labeled.rs

@@ -17,8 +17,8 @@ use vite_task_plan::{ExecutionGraph, ExecutionItemDisplay, ExecutionItemKind, Le
 use super::{
     CACHE_MISS_STYLE, COMMAND_STYLE, ColorizeExt, ExitStatus, GraphExecutionReporter,
     GraphExecutionReporterBuilder, LeafExecutionPath, LeafExecutionReporter, StdioConfig,
-    StdioSuggestion, format_cache_hit_message, format_command_display,
-    format_command_with_cache_status, format_error_message,
+    StdioSuggestion, format_command_display, format_command_with_cache_status,
+    format_error_message,
 };
 use crate::session::{
     cache::format_cache_status_summary,
@@ -28,9 +28,7 @@ use crate::session::{
 /// Information tracked for each leaf execution, used in the final summary.
 #[derive(Debug)]
 struct ExecutionInfo {
-    /// Display info for this execution. `None` for displayless executions
-    /// (e.g., synthetics reached via nested expansion).
-    display: Option<ExecutionItemDisplay>,
+    display: ExecutionItemDisplay,
     /// Cache status, determined at `start()`.
     cache_status: CacheStatus,
     /// Exit status from the process. `None` means no process was spawned (cache hit or in-process).
@@ -146,8 +144,7 @@ pub struct LabeledGraphReporter {
 )]
 impl GraphExecutionReporter for LabeledGraphReporter {
     fn new_leaf_execution(&mut self, path: &LeafExecutionPath) -> Box<dyn LeafExecutionReporter> {
-        // Look up display info from the graph using the path
-        let display = path.resolve_display(&self.graph).cloned();
+        let display = path.resolve_item(&self.graph).execution_item_display.clone();
         Box::new(LabeledLeafReporter {
             shared: Rc::clone(&self.shared),
             writer: Rc::clone(&self.writer),
@@ -164,16 +161,8 @@ impl GraphExecutionReporter for LabeledGraphReporter {
         let (summary_buf, result) = {
             let shared = self.shared.borrow();
 
-            // Print summary.
-            // Special case: single execution without display info (e.g., synthetic via
-            // nested expansion) → skip summary since there's nothing meaningful to show.
-            let is_single_displayless =
-                shared.executions.len() == 1 && shared.executions[0].display.is_none();
-            let summary_buf = if is_single_displayless {
-                None
-            } else {
-                Some(format_summary(&shared.executions, &shared.stats, &self.workspace_path))
-            };
+            let summary_buf =
+                Some(format_summary(&shared.executions, &shared.stats, &self.workspace_path));
 
             // Determine exit code based on failed tasks and infrastructure errors:
             // - Infrastructure errors (cache lookup, spawn failure) have error_message set
@@ -231,7 +220,7 @@ struct LabeledLeafReporter {
     shared: Rc<RefCell<SharedReporterState>>,
     writer: Rc<RefCell<Box<dyn AsyncWrite + Unpin>>>,
     /// Display info for this execution, looked up from the graph via the path.
-    display: Option<ExecutionItemDisplay>,
+    display: ExecutionItemDisplay,
     workspace_path: Arc<AbsolutePath>,
     /// Whether `start()` has been called. Used to determine if stats should be updated
     /// in `finish()` and whether to push an `ExecutionInfo` entry.
@@ -281,16 +270,14 @@ impl LeafExecutionReporter for LabeledLeafReporter {
 
         // Format command line with cache status (sync), then write asynchronously.
         // The shared borrow to read cache_status is brief and dropped before the await.
-        if let Some(ref display) = self.display {
-            let line = {
-                let shared = self.shared.borrow();
-                let cache_status = &shared.executions.last().unwrap().cache_status;
-                format_command_with_cache_status(display, &self.workspace_path, cache_status)
-            };
-            let mut writer = self.writer.borrow_mut();
-            let _ = writer.write_all(line.as_bytes()).await;
-            let _ = writer.flush().await;
-        }
+        let line = {
+            let shared = self.shared.borrow();
+            let cache_status = &shared.executions.last().unwrap().cache_status;
+            format_command_with_cache_status(&self.display, &self.workspace_path, cache_status)
+        };
+        let mut writer = self.writer.borrow_mut();
+        let _ = writer.write_all(line.as_bytes()).await;
+        let _ = writer.flush().await;
 
         StdioConfig {
             suggestion,
@@ -352,12 +339,6 @@ impl LeafExecutionReporter for LabeledLeafReporter {
             buf.extend_from_slice(format_error_message(message).as_bytes());
         }
 
-        // For executions without display info (synthetics via nested expansion) that are
-        // cache hits, print the cache hit message
-        if self.started && self.display.is_none() && self.is_cache_hit {
-            buf.extend_from_slice(format_cache_hit_message().as_bytes());
-        }
-
         // Add a trailing newline after each task's output for readability.
         // Skip if start() was never called (e.g. cache lookup failure) — there's
         // no task output to separate.
@@ -516,10 +497,7 @@ fn format_summary(
     );
 
     for (idx, exec) in executions.iter().enumerate() {
-        // Skip executions without display info (they have nothing to show in the summary)
-        let Some(ref display) = exec.display else {
-            continue;
-        };
+        let display = &exec.display;
 
         let task_display = &display.task_display;
 
@@ -677,13 +655,16 @@ mod tests {
     /// Build a `LabeledGraphReporter` for the given graph and return a leaf reporter
     /// for the first node's first item.
     fn build_labeled_leaf(graph: ExecutionGraph) -> Box<dyn LeafExecutionReporter> {
+        use vite_task_plan::execution_graph::ExecutionNodeIndex;
+
         let graph_arc = Arc::new(graph);
         let builder =
             Box::new(LabeledReporterBuilder::new(test_path(), Box::new(tokio::io::sink())));
         let mut reporter = builder.build(&graph_arc);
 
-        // Create a leaf reporter for the first node
-        let path = LeafExecutionPath::default();
+        // Create a leaf reporter for the first node's first item
+        let mut path = LeafExecutionPath::default();
+        path.push(ExecutionNodeIndex::new(0), 0);
         reporter.new_leaf_execution(&path)
     }
 

crates/vite_task/src/session/reporter/mod.rs

@@ -37,7 +37,9 @@ use smallvec::SmallVec;
 use tokio::io::AsyncWrite;
 use vite_path::AbsolutePath;
 use vite_str::Str;
-use vite_task_plan::{ExecutionGraph, ExecutionItem, ExecutionItemDisplay, ExecutionItemKind};
+use vite_task_plan::{
+    ExecutionGraph, ExecutionItem, ExecutionItemDisplay, ExecutionItemKind, LeafExecutionKind,
+};
 
 use super::{
     cache::format_cache_status_inline,
@@ -144,44 +146,52 @@ impl LeafExecutionPath {
         self.0.push(ExecutionPathItem { graph_node_ix, task_execution_item_index });
     }
 
-    /// Look up the [`ExecutionItemDisplay`] for the leaf identified by this path,
-    /// traversing through nested `Expanded` graphs as needed.
+    /// Resolve this path against a root execution graph, returning the final
+    /// [`ExecutionItem`] the path points to.
     ///
-    /// Returns `None` if the path is empty.
+    /// This is the shared traversal logic that walks through nested `Expanded`
+    /// graphs. Used by:
+    /// - `Index<&LeafExecutionPath> for ExecutionGraph` — extracts `&LeafExecutionKind`
+    /// - `new_leaf_execution` in `labeled.rs` — extracts `ExecutionItemDisplay`
     ///
     /// # Panics
     ///
-    /// Panics if an intermediate path element does not point to an `Expanded` item,
-    /// which indicates a bug in path construction.
-    fn resolve_display<'a>(
-        &self,
-        root_graph: &'a ExecutionGraph,
-    ) -> Option<&'a ExecutionItemDisplay> {
+    /// - If the path is empty (indicates a bug in path construction).
+    /// - If an intermediate path element points to a `Leaf` item instead of
+    ///   `Expanded` (only `Expanded` items contain nested graphs to descend into).
+    fn resolve_item<'a>(&self, root_graph: &'a ExecutionGraph) -> &'a ExecutionItem {
         let mut current_graph = root_graph;
+        let last_depth = self.0.len() - 1;
         for (depth, path_item) in self.0.iter().enumerate() {
             let item = path_item.resolve(current_graph);
-            let is_last = depth == self.0.len() - 1;
-            if is_last {
-                // Last element — return the display info regardless of Leaf/Expanded
-                return Some(&item.execution_item_display);
+            if depth == last_depth {
+                return item;
             }
-            // Intermediate element — must be Expanded so we can descend into it
             match &item.kind {
                 ExecutionItemKind::Expanded(nested_graph) => {
                     current_graph = nested_graph;
                 }
                 ExecutionItemKind::Leaf(_) => {
-                    // A Leaf in the middle of the path means the execution engine
-                    // pushed a Leaf node as an intermediate step, which is a bug —
-                    // only Expanded items can contain nested graphs to descend into.
                     unreachable!(
                         "LeafExecutionPath: intermediate element at depth {depth} is a Leaf, expected Expanded"
                     )
                 }
             }
         }
-        // Empty path
-        None
+        unreachable!("LeafExecutionPath: empty path")
+    }
+}
+
+impl std::ops::Index<&LeafExecutionPath> for ExecutionGraph {
+    type Output = LeafExecutionKind;
+
+    fn index(&self, path: &LeafExecutionPath) -> &Self::Output {
+        match &path.resolve_item(self).kind {
+            ExecutionItemKind::Leaf(kind) => kind,
+            ExecutionItemKind::Expanded(_) => {
+                unreachable!("LeafExecutionPath: final element is Expanded, expected Leaf")
+            }
+        }
     }
 }
 

crates/vite_task_plan/src/execution_graph.rs

@@ -1,4 +1,4 @@
-use std::ops::Deref;
+use std::ops::{Deref, Index};
 
 use petgraph::{
     graph::{DefaultIx, DiGraph, EdgeIndex, IndexType, NodeIndex},
@@ -134,7 +134,7 @@ impl<N, Ix: IndexType> Default for AcyclicGraph<N, Ix> {
 }
 
 /// Deref to the inner `DiGraph` so that read-only graph operations
-/// (`node_count()`, `node_weights()`, `node_indices()`, indexing by `NodeIndex`, etc.)
+/// (`node_count()`, `node_weights()`, `node_indices()`, etc.)
 /// work transparently on `AcyclicGraph`.
 impl<N, Ix: IndexType> Deref for AcyclicGraph<N, Ix> {
     type Target = DiGraph<N, (), Ix>;
@@ -144,6 +144,17 @@ impl<N, Ix: IndexType> Deref for AcyclicGraph<N, Ix> {
     }
 }
 
+/// Explicit `NodeIndex` indexing so that `graph[node_ix]` continues to work
+/// even when downstream crates add their own `Index` impls on `AcyclicGraph`
+/// (a direct `Index` impl shadows any `Index` that would be found through `Deref`).
+impl<N, Ix: IndexType> Index<NodeIndex<Ix>> for AcyclicGraph<N, Ix> {
+    type Output = N;
+
+    fn index(&self, index: NodeIndex<Ix>) -> &Self::Output {
+        &self.graph[index]
+    }
+}
+
 /// The execution graph type alias, specialized for task execution.
 pub type ExecutionGraph = AcyclicGraph<TaskExecution, ExecutionIx>;