From 52f8ead0f246464c4d4ff096dc4f357710fcc82d Mon Sep 17 00:00:00 2001
From: leeguooooo <guoli@zhihu.com>
Date: Sat, 9 May 2026 02:45:21 +0900
Subject: [PATCH] fix(click): wait for paint to settle so SPA renders complete
 before next command
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Closes a real-world race that broke X multi-tweet thread composition
(and similar SPA flows): clicking "Add post" returned immediately,
inserttext fired before React had committed the new textarea, the
keystroke landed on the dialog wrapper, and X interpreted the stray
input as a request to dismiss the modal.

After mouseReleased we now wait for two requestAnimationFrame ticks
plus a microtask boundary (~33ms at 60fps, bounded). That's enough
for React/Vue/Svelte to commit any state update scheduled by the
click handler. Errors during the wait are swallowed — a click never
fails because of post-processing.

Opt out for perf-sensitive scripts that don't drive SPA UIs:
  AGENT_BROWSER_CLICK_WAIT_STABLE=0
---
 cli/src/native/interaction.rs | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/cli/src/native/interaction.rs b/cli/src/native/interaction.rs
index 0c51ec7..3375ace 100644
--- a/cli/src/native/interaction.rs
+++ b/cli/src/native/interaction.rs
@@ -884,6 +884,38 @@ pub async fn tap_touch(
     Ok(())
 }
 
+/// After a click is dispatched, give the page two animation frames + a
+/// microtask boundary to let React/Vue/Svelte commit any state update
+/// scheduled by the click handler. Without this wait, follow-up commands
+/// (e.g. `inserttext` against the textbox the click was supposed to mount)
+/// race the renderer and can land on stale or wrong elements.
+///
+/// The wait is bounded to ~33ms in the common case (two RAFs at 60fps) and
+/// returns immediately on any error — never an exception path.
+///
+/// Set `AGENT_BROWSER_CLICK_WAIT_STABLE=0` to disable for perf-sensitive
+/// scripts that don't drive SPA UIs.
+async fn wait_for_paint_settled(client: &CdpClient, session_id: &str) {
+    if std::env::var("AGENT_BROWSER_CLICK_WAIT_STABLE").as_deref() == Ok("0") {
+        return;
+    }
+    let script = "new Promise(resolve => \
+        requestAnimationFrame(() => \
+            requestAnimationFrame(() => \
+                queueMicrotask(() => resolve(true)))))";
+    let _ = client
+        .send_command_typed::<_, Value>(
+            "Runtime.evaluate",
+            &EvaluateParams {
+                expression: script.to_string(),
+                return_by_value: Some(true),
+                await_promise: Some(true),
+            },
+            Some(session_id),
+        )
+        .await;
+}
+
 async fn dispatch_click(
     client: &CdpClient,
     session_id: &str,
@@ -955,6 +987,7 @@ async fn dispatch_click(
         )
         .await?;
 
+    wait_for_paint_settled(client, session_id).await;
     Ok(())
 }