cmux NEXT transcript: no caret at the end of a streaming reply

webviews/src/agent-session/acpmux/conversation/Markdown.tsx

@@ -726,11 +726,8 @@ export type FreshTail = { steps: Reveal[]; text: string; now: number };
 /// and a negative animation delay, so a re-render never restarts its fade. Only plain trailing
 /// text fades by step; a suffix with Markdown syntax or a line break draws as usual.
 function renderFresh(text: string, tail: FreshTail, opts: InlineOptions): ReactNode[] {
-  // The live edge: a soft bar after the newest character, out of the text's layout (no reflow
-  // when it leaves); it pulses only while the reveal waits for more (`.cv-md.is-waiting`).
-  const caret = <span key="caret" className="cv-caret" aria-hidden="true" />;
   const fresh = tail.text.trimEnd();
-  if (!fresh || !text.endsWith(fresh) || /[*`_~[\]()$\\\n]/.test(fresh)) return [...renderInline(text, opts), caret];
+  if (!fresh || !text.endsWith(fresh) || /[*`_~[\]()$\\\n]/.test(fresh)) return renderInline(text, opts);
   const out = renderInline(text.slice(0, text.length - fresh.length), opts);
   let end = fresh.length;
   const spans: ReactNode[] = [];
@@ -745,7 +742,7 @@ function renderFresh(text: string, tail: FreshTail, opts: InlineOptions): ReactN
     end = start;
   }
   if (end > 0) out.push(fresh.slice(0, end));
-  return [...out, ...spans, caret];
+  return [...out, ...spans];
 }
 
 /// A top-level block that renders again only when its parsed block changes: a streaming reply's
@@ -761,8 +758,6 @@ export type MarkdownProps = InlineOptions & {
   /** The newest revealed steps (RevealedMarkdown), which fade in at the end of the last block. */
   fresh?: Reveal[];
   now?: number;
-  /** The reveal has shown everything so far and waits for more: the live edge pulses. */
-  waiting?: boolean;
   /** Fences draw as plain lines, never a highlighted diff card (review comments inside a diff). */
   plainCode?: boolean;
 };
@@ -779,7 +774,6 @@ export function Markdown({
   streaming = false,
   fresh,
   now = 0,
-  waiting = false,
   githubRepository,
   plainCode = false,
 }: MarkdownProps) {
@@ -816,7 +810,7 @@ export function Markdown({
   // Fences this reply drew open: they hand over to the highlighted card once, when they close.
   const streamedFences = useRef(new Set<string>());
   const freshChars = fresh?.reduce((sum, step) => sum + step.count, 0) ?? 0;
-  // Only a revealed reply (RevealedMarkdown passes `fresh`) draws the live edge.
+  // Only a revealed reply (RevealedMarkdown passes `fresh`) fades its newest text in.
   const freshTail: FreshTail | undefined =
     streaming && fresh
       ? { steps: fresh, text: freshChars ? children.slice(children.length - freshChars) : "", now }
@@ -852,7 +846,7 @@ export function Markdown({
     .filter(({ entry }) => entry.block.type === "footnote")
     .sort((a, b) => noteRank(a.entry.block, opts) - noteRank(b.entry.block, opts));
   return (
-    <div className={`cv-md selectable ${className}${streaming && waiting ? " is-waiting" : ""}`}>
+    <div className={`cv-md selectable ${className}`}>
       {blocks.map((entry, index) => (entry.block.type === "footnote" ? null : draw(entry, index)))}
       {notes.length > 0 && (
         <section className="cv-footnotes" role="doc-endnotes">

webviews/src/agent-session/acpmux/conversation/RevealedMarkdown.tsx

@@ -21,31 +21,25 @@ export type Reveal = { id: number; count: number; born: number };
 /// How long newly revealed text fades in (acp-streaming.md "Reveal animation").
 export const FADE_MS = 160;
 
-type Shown = { length: number; fresh: Reveal[]; now: number; settled: boolean };
+type Shown = { length: number; fresh: Reveal[]; now: number };
 /// React commits at most this often while revealing; fades run every display frame on the
 /// compositor, so 60 commits a second read the same as 120 at half the main-thread cost.
 const COMMIT_MS = 1000 / 60;
 
 /// The part of `text` to show this frame, and the steps still fading in.
-export function useStreamReveal(
-  text: string,
-  streaming: boolean,
-): { visible: string; fresh: Reveal[]; now: number; settled: boolean } {
+export function useStreamReveal(text: string, streaming: boolean): { visible: string; fresh: Reveal[]; now: number } {
   const reveal = useRef<StreamReveal | null>(null);
   const reduce = useRef<boolean | null>(null);
   reduce.current ??= reducedMotion();
   // Text there when the row mounts shows at once; only what arrives after it flows in.
   reveal.current ??= new StreamReveal({ initial: text, reduceMotion: reduce.current });
-  const [shown, setShown] = useState<Shown>(() => ({ length: text.length, fresh: [], now: 0, settled: true }));
+  const [shown, setShown] = useState<Shown>(() => ({ length: text.length, fresh: [], now: 0 }));
   const latest = useRef({ text, streaming, shown });
   latest.current = { text, streaming, shown };
   const nextId = useRef(0);
   useLayoutEffect(() => {
     const current = reveal.current!;
-    if (current.settled && shown.length >= text.length && !shown.fresh.length) {
-      if (!shown.settled) setShown({ ...shown, settled: true });
-      return;
-    }
+    if (current.settled && shown.length >= text.length && !shown.fresh.length) return;
     let handle = 0;
     let lastCommit: number | undefined;
     const tick = (now: number) => {
@@ -70,7 +64,7 @@ export function useStreamReveal(
       const fresh = away ? [] : before.fresh.filter((step) => now - step.born < FADE_MS);
       if (length > before.length && !reduce.current && !away)
         fresh.push({ id: (nextId.current += 1), count: length - before.length, born: now });
-      const next = { length, fresh, now, settled: current.settled };
+      const next = { length, fresh, now };
       latest.current.shown = next;
       setShown(next);
       if (!current.settled || fresh.length) handle = revealFrames.request(tick);
@@ -84,7 +78,6 @@ export function useStreamReveal(
     visible: text.slice(0, Math.min(shown.length, text.length)),
     fresh: shown.fresh,
     now: shown.now,
-    settled: shown.settled && shown.length >= text.length,
   };
 }
 
@@ -115,9 +108,9 @@ function Revealed({
   streaming: boolean;
   githubRepository?: string;
 }) {
-  const { visible, fresh, now, settled } = useStreamReveal(text, streaming);
+  const { visible, fresh, now } = useStreamReveal(text, streaming);
   return (
-    <Markdown streaming={streaming} fresh={fresh} now={now} waiting={settled} githubRepository={githubRepository}>
+    <Markdown streaming={streaming} fresh={fresh} now={now} githubRepository={githubRepository}>
       {visible}
     </Markdown>
   );

webviews/src/agent-session/acpmux/conversation/StreamingEdge.test.tsx

@@ -0,0 +1,21 @@
+// l10n-allow-file: test fixture reply text, not shipped UI.
+// A streaming reply ends at its newest character: no caret or bar after it, while the reveal
+// writes or while it waits for more (Leo 2026-10-20: the blinking caret goes).
+import { expect, test } from "bun:test";
+import { renderToStaticMarkup } from "react-dom/server";
+import { Markdown } from "./Markdown";
+
+const fresh = [{ id: 1, count: 5, born: 0 }];
+
+test("a streaming reply draws no caret after its text", () => {
+  // Mid-reveal (the newest step fading in) and caught up (nothing fading, waiting for more).
+  for (const steps of [fresh, []]) {
+    const html = renderToStaticMarkup(
+      <Markdown streaming fresh={steps} now={100}>
+        {"Hello there world"}
+      </Markdown>,
+    );
+    expect(html).toContain("world");
+    expect(html).not.toContain("cv-caret");
+  }
+});

webviews/src/agent-session/acpmux/conversation/conversation.css

@@ -1861,40 +1861,6 @@ pre.cv-math-source {
   animation: cv-enter-fade var(--agent-motion-in, 180ms) var(--agent-ease-out, ease-out) both;
 }
 
-/* R104: the live edge, a soft bar after the newest character while a reply streams. It takes no
- * width (the bar is absolutely placed), so the text never reflows when it leaves. It pulses only
- * while the reveal has caught up and waits for more. */
-.cv-caret {
-  position: relative;
-  display: inline-block;
-  width: 0;
-  height: 1em;
-  vertical-align: -0.12em;
-}
-.cv-caret::after {
-  content: "";
-  position: absolute;
-  left: 2px;
-  top: 0.05em;
-  width: 0.5em;
-  height: 0.9em;
-  border-radius: 2px;
-  background: color-mix(in srgb, var(--cv-text) 55%, transparent);
-}
-@keyframes cv-caret-wait {
-  50% {
-    opacity: 0.35;
-  }
-}
-@media (prefers-reduced-motion: no-preference) {
-  .cv-md.is-waiting .cv-caret::after {
-    animation: cv-caret-wait 1s ease-in-out infinite;
-  }
-}
-:root[data-status-indicators="static"] .cv-md.is-waiting .cv-caret::after {
-  animation: none;
-}
-
 /* Footnotes (Markdown.tsx): a superscript number that scrolls to its note, and the notes
    under a rule at the end of the reply, in a smaller, quieter type. */
 .cv-fnref {

webviews/test/static-status-loops.test.ts

@@ -4,9 +4,9 @@
 // payload (`statusIndicators`), which this test runs as the app does, and under it, or under Reduce
 // Motion, no web loop may run: the mic's wait pulse, the model picker and harness spinners, the
 // floating chat's breathing dot, the Thinking sweep, the running line's working dots, the todo
-// list's spinner, the activity line's dots, the reply caret's wait pulse, the Jump to
-// Latest dots and Home's "writing" pulse. The diff viewer does not get the pane's theme, so its
-// spinners stop under Reduce Motion alone. Static also gives the color-only marks a shape each.
+// list's spinner, the activity line's dots, the Jump to Latest dots and Home's "writing" pulse.
+// The diff viewer does not get the pane's theme, so its spinners stop under Reduce Motion alone.
+// Static also gives the color-only marks a shape each.
 // This loads the real stylesheets in Chromium and lists the animations that never end.
 import { readFileSync } from "node:fs";
 import { afterAll, beforeAll, describe, expect, setDefaultTimeout, test } from "bun:test";
@@ -48,7 +48,6 @@ await requireBrowserLane("static-status-loops.test.ts", async () => {
     `<span class="acpmux-floating-status" data-status="streaming"></span>` +
     `<div class="cv-md"><span class="cv-thinking">Thinking</span></div>` +
     `<div class="cv-worked"><span class="cv-working-mark"><span></span><span></span><span></span></span></div>` +
-    `<div class="cv-md is-waiting"><span class="cv-caret"></span></div>` +
     `<button class="acpmux-jump-latest" data-shown data-working><span class="acpmux-jump-latest__dots"><i></i><i></i><i></i></span></button>` +
     `<ul class="cv-plan"><li class="cv-plan__item" data-status="in_progress"><span class="cv-plan__mark"></span></li></ul>` +
     `<div class="cv-activity"><span class="cv-activity__dots"><span></span><span></span><span></span></span></div>` +