fix: server-side 20s blocking in get_test_result to prevent agent poll spam

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/http/mcp/shell_tools.rs

@@ -471,11 +471,15 @@ pub(super) async fn tool_run_tests(args: &Value, ctx: &AppContext) -> Result<Str
     .map_err(|e| format!("Serialization error: {e}"))
 }
 
+/// How long `get_test_result` blocks server-side before returning "running".
+/// This prevents agents from burning turns polling every 2 seconds.
+const TEST_POLL_BLOCK_SECS: u64 = 20;
+
 /// Check on a running test job and return results if complete.
 ///
-/// Returns `{"status": "running", "elapsed_secs": N}` if still in progress,
+/// Blocks for up to 15 seconds, checking every second. Returns immediately
-/// or the full test result if finished. If no job exists for the worktree,
+/// when the test finishes, or after 15s with `{"status": "running"}`.
-/// returns an error.
+/// This server-side blocking prevents agents from wasting turns polling.
 pub(super) async fn tool_get_test_result(
     args: &Value,
     ctx: &AppContext,
@@ -489,6 +493,42 @@ pub(super) async fn tool_get_test_result(
             .map_err(|e| format!("Cannot canonicalize project root: {e}"))?,
     };
 
+    // Block for up to TEST_POLL_BLOCK_SECS, checking once per second.
+    let test_jobs = ctx.test_jobs.clone();
+    let wd = working_dir.clone();
+    for _ in 0..TEST_POLL_BLOCK_SECS {
+        {
+            let mut jobs = test_jobs.lock().map_err(|e| e.to_string())?;
+            if let Some(job) = jobs.get_mut(&wd) {
+                if let Some(child) = job.child.as_mut() {
+                    match child.try_wait() {
+                        Ok(Some(status)) => {
+                            let result = collect_child_result(child, status);
+                            job.child = None;
+                            job.result = Some(result.clone());
+                            jobs.remove(&wd);
+                            return format_test_result(&result);
+                        }
+                        Ok(None) => {} // still running, keep waiting
+                        Err(e) => {
+                            jobs.remove(&wd);
+                            return Err(format!("Failed to check child status: {e}"));
+                        }
+                    }
+                } else if let Some(result) = job.result.clone() {
+                    jobs.remove(&wd);
+                    return format_test_result(&result);
+                }
+            } else {
+                return Err(
+                    "No test job running for this worktree. Call run_tests first.".to_string(),
+                );
+            }
+        }
+        tokio::time::sleep(std::time::Duration::from_secs(1)).await;
+    }
+
+    // Still running after blocking period — return status.
     let mut jobs = ctx.test_jobs.lock().map_err(|e| e.to_string())?;
 
     let job = jobs.get_mut(&working_dir).ok_or_else(|| {