bun test: nest results under describe scopes instead of repeating the scope path

docs/guides/test/coverage-threshold.mdx

@@ -12,8 +12,9 @@ bun test --coverage
 
 ```txt
 test.test.ts:
-✓ math > add [0.71ms]
-✓ math > multiply [0.03ms]
+math
+  ✓ add [0.71ms]
+  ✓ multiply [0.03ms]
 ✓ random [0.13ms]
 -------------|---------|---------|-------------------
 File         | % Funcs | % Lines | Uncovered Line #s

docs/guides/test/coverage.mdx

@@ -19,8 +19,9 @@ bun test --coverage
 ```txt
 
 test.test.ts:
-✓ math > add [0.71ms]
-✓ math > multiply [0.03ms]
+math
+  ✓ add [0.71ms]
+  ✓ multiply [0.03ms]
 ✓ random [0.13ms]
 -------------|---------|---------|-------------------
 File         | % Funcs | % Lines | Uncovered Line #s

docs/test/reporters.mdx

@@ -41,6 +41,22 @@ test/package-json-lint.test.ts:
 Ran 4 tests across 1 files. [0.66ms]
 ```
 
+Tests inside a `describe` block are nested beneath their scope, which is printed once:
+
+```sh terminal icon="terminal"
+test/math.test.ts:
+math
+  arithmetic
+    ✓ add [0.12ms]
+    ✓ subtract [0.04ms]
+  ✓ is a module [0.03ms]
+✓ top-level test [0.02ms]
+
+ 4 pass
+ 0 fail
+Ran 4 tests across 1 files. [0.31ms]
+```
+
 ### Dots Reporter
 
 The dots reporter shows `.` for passing tests and prints full error details for failures, useful for large test suites.

src/runtime/cli/test/parallel/Coordinator.rs

@@ -50,6 +50,9 @@ pub struct Coordinator<'a> {
     /// from concurrent workers interleave; whenever the source file changes the
     /// header is re-emitted so every line has visible context. None at start.
     pub last_header_idx: Option<u32>,
+    /// Describe-scope path whose headers have already been printed under the
+    /// current `last_header_idx`. Cleared whenever the file header is re-emitted.
+    pub printed_scope_path: Vec<u8>,
     pub frame: Frame,
     pub parallel_limit: u32,
     pub scale_up_after_ms: i64,
@@ -307,6 +310,7 @@ impl<'a> Coordinator<'a> {
             return;
         }
         self.last_header_idx = Some(file_idx);
+        self.printed_scope_path.clear();
         let _ = write!(
             Output::error_writer(),
             "\n{}:\n",
@@ -344,6 +348,7 @@ impl<'a> Coordinator<'a> {
             }
             frame::Kind::TestDone => {
                 let idx = rd.u32_();
+                let scope_path = rd.str();
                 let formatted = rd.str();
                 if w.inflight != Some(idx) {
                     return;
@@ -358,6 +363,11 @@ impl<'a> Coordinator<'a> {
                 if !is_dot {
                     self.break_dots();
                     self.ensure_header(idx);
+                    CommandLineReporter::emit_scope_headers(
+                        &mut self.printed_scope_path,
+                        scope_path,
+                        Output::error_writer(),
+                    );
                 }
                 let _ = Output::error_writer().write_all(formatted);
                 self.last_printed_dot = is_dot;

src/runtime/cli/test/parallel/Frame.rs

@@ -10,7 +10,8 @@ pub enum Kind {
     Ready,
     /// u32 file_idx
     FileStart,
-    /// u32 file_idx, str formatted_line (ANSI included; printed verbatim)
+    /// u32 file_idx, str scope_path (`\x1f`-separated describe names, outermost
+    /// first), str formatted_line (ANSI included; printed verbatim)
     TestDone,
     /// 9 × u32: file_idx, pass, fail, skip, todo, expectations, skipped_label, files, unhandled
     FileDone,

src/runtime/cli/test/parallel/runner.rs

@@ -225,6 +225,7 @@ pub fn run_as_coordinator(
         junit_fragments: Vec::new(),
         coverage_fragments: Vec::new(),
         last_header_idx: None,
+        printed_scope_path: Vec::new(),
         frame: Frame::default(),
         files_done: 0,
         spawned_count: 0,
@@ -803,9 +804,10 @@ static WORKER_CMDS: bun_core::RacyCell<Option<*mut WorkerCommands>> = bun_core::
 // pointee outlives all callers (process exits before it's dropped).
 
 /// Called from `CommandLineReporter.handleTestCompleted` in the worker with the
-/// fully-formatted status line (✓/✗ + scopes + name + duration, including ANSI
-/// codes). The coordinator prints these bytes verbatim so output matches serial.
-pub fn worker_emit_test_done(file_idx: u32, formatted_line: &[u8]) {
+/// describe-scope path plus the fully-formatted status line (✓/✗ + indent + name
+/// + duration, including ANSI codes). The coordinator prints the scope headers it
+/// hasn't printed yet, then these bytes verbatim, so output matches serial.
+pub fn worker_emit_test_done(file_idx: u32, scope_path: &[u8], formatted_line: &[u8]) {
     // SAFETY: single-threaded worker; WORKER_CMDS only written/read on this thread.
     let Some(cmds_ptr) = (unsafe { WORKER_CMDS.read() }) else {
         return;
@@ -817,6 +819,7 @@ pub fn worker_emit_test_done(file_idx: u32, formatted_line: &[u8]) {
     let wf = unsafe { &mut *WORKER_FRAME.get() };
     wf.begin(frame::Kind::TestDone);
     wf.u32_(file_idx);
+    wf.str(scope_path);
     wf.str(formatted_line);
     cmds.send(wf.finish());
 }