Fix autocomplete popover flicker

packages/app/e2e/composer-autocomplete.spec.ts

@@ -0,0 +1,458 @@
+import { buildHostWorkspaceRoute } from "@/utils/host-routes";
+import { expect, test, type Page } from "./fixtures";
+import { composerLocator, expectComposerVisible } from "./helpers/composer";
+import { connectTerminalClient, type TerminalPerfDaemonClient } from "./helpers/terminal-perf";
+import { createTempGitRepo } from "./helpers/workspace";
+import { expectWorkspaceTabVisible } from "./helpers/archive-tab";
+
+const TEST_COMMANDS = [
+  {
+    name: "tdd",
+    description: "Write a red test, verify it fails for the right reason, implement to green",
+    argumentHint: "",
+  },
+  {
+    name: "help",
+    description: "Show help for the current agent session and available slash commands",
+    argumentHint: "",
+  },
+  {
+    name: "hello",
+    description: "Insert a friendly greeting prompt into the current composer",
+    argumentHint: "",
+  },
+  {
+    name: "heapdump",
+    description: "Dump the JavaScript heap for local desktop debugging",
+    argumentHint: "",
+  },
+  {
+    name: "health",
+    description: "Show runtime health checks and connection diagnostics",
+    argumentHint: "",
+  },
+  {
+    name: "history",
+    description: "Summarize recent session history",
+    argumentHint: "",
+  },
+  {
+    name: "handoff",
+    description: "Prepare a complete handoff note for another agent",
+    argumentHint: "[agent]",
+  },
+  {
+    name: "hover",
+    description: "Audit hover behavior in desktop web surfaces",
+    argumentHint: "",
+  },
+  {
+    name: "harness",
+    description: "Inspect the local test harness configuration",
+    argumentHint: "",
+  },
+  {
+    name: "hydrate",
+    description: "Refresh persisted state used by the current workspace",
+    argumentHint: "",
+  },
+  {
+    name: "highlight",
+    description: "Highlight important changes in the active diff",
+    argumentHint: "",
+  },
+  {
+    name: "home",
+    description: "Navigate back to the workspace home surface",
+    argumentHint: "",
+  },
+  {
+    name: "host",
+    description: "Inspect host connection metadata",
+    argumentHint: "",
+  },
+] as const;
+
+interface PopoverFrame {
+  exists: boolean;
+  top: number;
+  bottom: number;
+  height: number;
+  opacity: number;
+  display: string;
+  visibility: string;
+  timestamp: number;
+}
+
+interface PopoverFrameRecorderWindow extends Window {
+  __composerAutocompleteFrames?: PopoverFrame[];
+  __stopComposerAutocompleteFrameRecorder?: () => void;
+}
+
+function getServerId(): string {
+  const serverId = process.env.E2E_SERVER_ID;
+  if (!serverId) {
+    throw new Error("E2E_SERVER_ID is not set.");
+  }
+  return serverId;
+}
+
+function getDaemonPort(): string {
+  const daemonPort = process.env.E2E_DAEMON_PORT;
+  if (!daemonPort || daemonPort === "6767") {
+    throw new Error("E2E_DAEMON_PORT must point at the isolated e2e daemon.");
+  }
+  return daemonPort;
+}
+
+function escapeRegex(value: string): string {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
+async function installListCommandsStub(page: Page): Promise<void> {
+  await page.routeWebSocket(new RegExp(`:${escapeRegex(getDaemonPort())}\\b`), (ws) => {
+    const server = ws.connectToServer();
+
+    ws.onMessage((message) => {
+      server.send(message);
+    });
+
+    server.onMessage((message) => {
+      if (typeof message !== "string") {
+        ws.send(message);
+        return;
+      }
+
+      try {
+        const parsed = JSON.parse(message) as {
+          type?: string;
+          message?: {
+            type?: string;
+            payload?: {
+              commands?: unknown;
+              error?: string | null;
+            };
+          };
+        };
+        if (
+          parsed.type === "session" &&
+          parsed.message?.type === "list_commands_response" &&
+          parsed.message.payload
+        ) {
+          parsed.message.payload.commands = TEST_COMMANDS;
+          parsed.message.payload.error = null;
+          ws.send(JSON.stringify(parsed));
+          return;
+        }
+      } catch {
+        // Forward non-JSON frames unchanged.
+      }
+
+      ws.send(message);
+    });
+  });
+}
+
+async function openProject(client: TerminalPerfDaemonClient, cwd: string): Promise<void> {
+  const opened = await client.openProject(cwd);
+  if (!opened.workspace) {
+    throw new Error(opened.error ?? `Failed to open project ${cwd}`);
+  }
+}
+
+async function cleanupWithin(timeoutMs: number, cleanup: () => Promise<void>): Promise<void> {
+  const operation = cleanup().catch(() => undefined);
+  await Promise.race([operation, new Promise<void>((resolve) => setTimeout(resolve, timeoutMs))]);
+}
+
+async function openReadyMockAgent(page: Page): Promise<{
+  cleanup: () => Promise<void>;
+}> {
+  const repo = await createTempGitRepo("autocomplete-popover-");
+  const client = await connectTerminalClient();
+
+  try {
+    await openProject(client, repo.path);
+    const agent = await client.createAgent({
+      provider: "mock",
+      cwd: repo.path,
+      title: "Autocomplete popover regression",
+      modeId: "load-test",
+      model: "ten-second-stream",
+    });
+    const route = `${buildHostWorkspaceRoute(
+      getServerId(),
+      repo.path,
+    )}?open=${encodeURIComponent(`agent:${agent.id}`)}`;
+    await page.goto(route);
+    await page.waitForURL(
+      (url) => url.pathname.includes("/workspace/") && !url.searchParams.has("open"),
+      { timeout: 60_000 },
+    );
+    await expectWorkspaceTabVisible(page, agent.id);
+    await expectComposerVisible(page);
+    return {
+      cleanup: async () => {
+        await cleanupWithin(2_000, () => client.close());
+        await cleanupWithin(2_000, () => repo.cleanup());
+      },
+    };
+  } catch (error) {
+    await cleanupWithin(2_000, () => client.close());
+    await cleanupWithin(2_000, () => repo.cleanup());
+    throw error;
+  }
+}
+
+async function visiblePopoverBox(
+  page: Page,
+): Promise<{ top: number; bottom: number; height: number }> {
+  const popover = page.getByTestId("composer-autocomplete-popover");
+  await expect(popover).toBeVisible({ timeout: 30_000 });
+  await expect
+    .poll(
+      async () =>
+        popover.evaluate((element) => {
+          const style = window.getComputedStyle(element);
+          return Number(style.opacity);
+        }),
+      { timeout: 30_000 },
+    )
+    .toBeGreaterThan(0.95);
+  const box = await popover.boundingBox();
+  if (!box) {
+    throw new Error("Autocomplete popover did not produce a bounding box.");
+  }
+  return {
+    top: box.y,
+    bottom: box.y + box.height,
+    height: box.height,
+  };
+}
+
+async function startPopoverFrameRecorder(page: Page): Promise<void> {
+  await page.evaluate(() => {
+    const win = window as PopoverFrameRecorderWindow;
+    win.__composerAutocompleteFrames = [];
+    let active = true;
+
+    const record = () => {
+      if (!active) return;
+
+      const element = document.querySelector('[data-testid="composer-autocomplete-popover"]');
+      if (element instanceof HTMLElement) {
+        const rect = element.getBoundingClientRect();
+        const style = window.getComputedStyle(element);
+        win.__composerAutocompleteFrames?.push({
+          exists: true,
+          top: rect.top,
+          bottom: rect.bottom,
+          height: rect.height,
+          opacity: Number(style.opacity),
+          display: style.display,
+          visibility: style.visibility,
+          timestamp: performance.now(),
+        });
+      } else {
+        win.__composerAutocompleteFrames?.push({
+          exists: false,
+          top: 0,
+          bottom: 0,
+          height: 0,
+          opacity: 0,
+          display: "none",
+          visibility: "hidden",
+          timestamp: performance.now(),
+        });
+      }
+
+      window.requestAnimationFrame(record);
+    };
+
+    win.__stopComposerAutocompleteFrameRecorder = () => {
+      active = false;
+    };
+    window.requestAnimationFrame(record);
+  });
+}
+
+async function stopPopoverFrameRecorder(page: Page): Promise<PopoverFrame[]> {
+  return page.evaluate(() => {
+    const win = window as PopoverFrameRecorderWindow;
+    win.__stopComposerAutocompleteFrameRecorder?.();
+    return win.__composerAutocompleteFrames ?? [];
+  });
+}
+
+function visiblePopoverFrames(frames: PopoverFrame[]): PopoverFrame[] {
+  return frames.filter(
+    (frame) =>
+      frame.exists &&
+      frame.height > 0 &&
+      frame.opacity > 0.95 &&
+      frame.display !== "none" &&
+      frame.visibility !== "hidden",
+  );
+}
+
+function formatFrame(frame: PopoverFrame | undefined): string {
+  if (!frame) return "none";
+  return JSON.stringify({
+    top: Math.round(frame.top),
+    bottom: Math.round(frame.bottom),
+    height: Math.round(frame.height),
+    opacity: frame.opacity,
+  });
+}
+
+function expectPopoverFramesStable(frames: PopoverFrame[]): void {
+  const visibleFrames = visiblePopoverFrames(frames);
+  expect(visibleFrames.length).toBeGreaterThan(0);
+
+  const finalFrame = visibleFrames[visibleFrames.length - 1];
+  const jumpingFrame = visibleFrames.find(
+    (frame) =>
+      Math.abs(frame.top - finalFrame.top) > 4 ||
+      Math.abs(frame.bottom - finalFrame.bottom) > 4 ||
+      Math.abs(frame.height - finalFrame.height) > 4,
+  );
+
+  expect(
+    jumpingFrame,
+    `expected first visible popover paint to be stable; first=${formatFrame(
+      visibleFrames[0],
+    )} jumping=${formatFrame(jumpingFrame)} final=${formatFrame(finalFrame)}`,
+  ).toBeUndefined();
+}
+
+function expectPopoverDoesNotDisappearAfterFirstVisible(frames: PopoverFrame[]): void {
+  const firstVisibleIndex = frames.findIndex(
+    (frame) =>
+      frame.exists &&
+      frame.height > 0 &&
+      frame.opacity > 0.95 &&
+      frame.display !== "none" &&
+      frame.visibility !== "hidden",
+  );
+  expect(firstVisibleIndex).toBeGreaterThanOrEqual(0);
+
+  const hiddenFrame = frames
+    .slice(firstVisibleIndex)
+    .find((frame) => !frame.exists || frame.opacity < 0.95);
+  expect(
+    hiddenFrame,
+    `expected mounted popover to stay visible while filtering; hidden=${formatFrame(hiddenFrame)}`,
+  ).toBeUndefined();
+}
+
+test.describe("Composer autocomplete", () => {
+  test("does not flash at the wrong position on the first slash command paint", async ({
+    page,
+  }) => {
+    await installListCommandsStub(page);
+    const agent = await openReadyMockAgent(page);
+
+    try {
+      const input = composerLocator(page);
+      await expect(input).toBeEditable({ timeout: 30_000 });
+      await input.click();
+
+      await startPopoverFrameRecorder(page);
+      await page.keyboard.type("/");
+      await expect(page.getByText("/help", { exact: true })).toBeVisible({ timeout: 30_000 });
+      await page.waitForTimeout(250);
+      const frames = await stopPopoverFrameRecorder(page);
+
+      expectPopoverFramesStable(frames);
+    } finally {
+      await agent.cleanup();
+    }
+  });
+
+  test("does not jump when deleting a slash command search", async ({ page }) => {
+    await installListCommandsStub(page);
+    const agent = await openReadyMockAgent(page);
+
+    try {
+      const input = composerLocator(page);
+      await expect(input).toBeEditable({ timeout: 30_000 });
+
+      await input.fill("/he");
+      const popover = page.getByTestId("composer-autocomplete-popover");
+      await expect(popover.getByText("/help", { exact: true }).first()).toBeVisible({
+        timeout: 30_000,
+      });
+      const beforeDelete = await visiblePopoverBox(page);
+
+      await input.press("Backspace");
+      await expect(input).toHaveValue("/h");
+      await expect(popover.getByText("/history", { exact: true }).first()).toBeVisible({
+        timeout: 30_000,
+      });
+      const afterDelete = await visiblePopoverBox(page);
+
+      expect(Math.abs(afterDelete.bottom - beforeDelete.bottom)).toBeLessThanOrEqual(4);
+      expect(afterDelete.height).toBeGreaterThan(beforeDelete.height);
+    } finally {
+      await agent.cleanup();
+    }
+  });
+
+  test("shrinks to filtered slash command results without moving the bottom edge", async ({
+    page,
+  }) => {
+    await installListCommandsStub(page);
+    const agent = await openReadyMockAgent(page);
+
+    try {
+      const input = composerLocator(page);
+      await expect(input).toBeEditable({ timeout: 30_000 });
+
+      await input.fill("/");
+      const popover = page.getByTestId("composer-autocomplete-popover");
+      await expect(popover.getByText("/help", { exact: true }).first()).toBeVisible({
+        timeout: 30_000,
+      });
+      const allCommands = await visiblePopoverBox(page);
+
+      await input.fill("/tdd");
+      await expect(popover.getByText("/tdd", { exact: true }).first()).toBeVisible({
+        timeout: 30_000,
+      });
+      const oneCommand = await visiblePopoverBox(page);
+
+      expect(Math.abs(oneCommand.bottom - allCommands.bottom)).toBeLessThanOrEqual(4);
+      expect(oneCommand.height).toBeLessThan(allCommands.height - 40);
+    } finally {
+      await agent.cleanup();
+    }
+  });
+
+  test("stays visible while filtering slash command results", async ({ page }) => {
+    await installListCommandsStub(page);
+    const agent = await openReadyMockAgent(page);
+
+    try {
+      const input = composerLocator(page);
+      await expect(input).toBeEditable({ timeout: 30_000 });
+
+      await input.fill("/");
+      const popover = page.getByTestId("composer-autocomplete-popover");
+      await expect(popover.getByText("/help", { exact: true }).first()).toBeVisible({
+        timeout: 30_000,
+      });
+
+      await startPopoverFrameRecorder(page);
+      await page.keyboard.type("tdd", { delay: 40 });
+      await expect(popover.getByText("/tdd", { exact: true }).first()).toBeVisible({
+        timeout: 30_000,
+      });
+      await page.waitForTimeout(250);
+      const frames = await stopPopoverFrameRecorder(page);
+
+      expectPopoverDoesNotDisappearAfterFirstVisible(frames);
+    } finally {
+      await agent.cleanup();
+    }
+  });
+});

packages/app/src/components/ui/autocomplete-popover.tsx

@@ -1,5 +1,5 @@
-import { useCallback, useEffect, useMemo, useState, type ReactElement } from "react";
+import { useEffect, useMemo, useState, type ReactElement } from "react";
-import { Keyboard, Platform, StatusBar, View, type LayoutChangeEvent } from "react-native";
+import { Keyboard, Platform, StatusBar, View, useWindowDimensions } from "react-native";
 import { Portal } from "@gorhom/portal";
 import Animated, {
   useAnimatedStyle,
@@ -54,7 +54,7 @@ export function AutocompletePopover({
   emptyText,
 }: AutocompletePopoverProps): ReactElement | null {
   const [anchorRect, setAnchorRect] = useState<Rect | null>(null);
-  const [contentSize, setContentSize] = useState<{ width: number; height: number } | null>(null);
+  const { height: windowHeight } = useWindowDimensions();
   const insets = useSafeAreaInsets();
 
   const { height: rawKeyboardHeight } = useReanimatedKeyboardAnimation();
@@ -76,7 +76,6 @@ export function AutocompletePopover({
   useEffect(() => {
     if (!visible) {
       setAnchorRect(null);
-      setContentSize(null);
       return;
     }
     let cancelled = false;
@@ -106,34 +105,15 @@ export function AutocompletePopover({
     };
   }, [visible, anchorRef, openShift, shift]);
 
-  const handleLayout = useCallback((event: LayoutChangeEvent) => {
-    const { width, height } = event.nativeEvent.layout;
-    setContentSize({ width, height });
-  }, []);
-
   const baseStyle = useMemo(() => {
     if (!anchorRect) return null;
-    if (!contentSize) {
-      // Have the anchor, waiting on the popover's own height. Render with the
-      // final width so the inner Autocomplete lays out at its final size, but
-      // stay invisible — the first visible paint will already be at the correct
-      // top. Mirrors combobox.tsx `shouldHideDesktopContent`. See
-      // docs/floating-panels.md "the two-measurement flash".
-      return inlineUnistylesStyle({
-        position: "absolute" as const,
-        top: 0,
-        left: anchorRect.x,
-        width: anchorRect.width,
-        opacity: 0,
-      });
-    }
     return inlineUnistylesStyle({
       position: "absolute" as const,
-      top: anchorRect.y - contentSize.height - OFFSET_FROM_ANCHOR,
+      bottom: windowHeight - anchorRect.y + OFFSET_FROM_ANCHOR,
       left: anchorRect.x,
       width: anchorRect.width,
     });
-  }, [anchorRect, contentSize]);
+  }, [anchorRect, windowHeight]);
 
   const animatedTransformStyle = useAnimatedStyle(() => ({
     transform: [{ translateY: openShift.value - shift.value }],
@@ -149,7 +129,7 @@ export function AutocompletePopover({
   return (
     <Portal>
       <View style={styles.overlay} pointerEvents="box-none">
-        <Animated.View style={composedStyle} onLayout={handleLayout}>
+        <Animated.View testID="composer-autocomplete-popover" style={composedStyle}>
           <Autocomplete
             options={options}
             selectedIndex={selectedIndex}

packages/app/src/components/ui/autocomplete.tsx

@@ -206,6 +206,7 @@ export function Autocomplete({
     [ensureActiveItemVisible],
   );
 
+  const selectedOption = options[selectedIndex];
   const containerStyle = useMemo(() => [styles.container, { maxHeight }], [maxHeight]);
 
   if (isLoading) {
@@ -238,8 +239,6 @@ export function Autocomplete({
     );
   }
 
-  const selectedOption = options[selectedIndex];
-
   return (
     <View style={styles.outerWrapper}>
       {selectedOption?.kind === "command" && selectedOption.description ? (

packages/app/src/hooks/use-agent-autocomplete.ts

@@ -168,7 +168,7 @@ function resolveAutocompleteIsLoading(args: {
   optionsLength: number;
 }): boolean {
   if (args.mode === "command") {
-    return args.isCommandsLoading;
+    return args.isCommandsLoading && args.optionsLength === 0;
   }
   if (args.mode === "file") {
     return (
@@ -251,7 +251,7 @@ export function useAgentAutocomplete(input: UseAgentAutocompleteInput): AgentAut
   const isConnected = useHostRuntimeIsConnected(serverId);
 
   const mode = resolveAutocompleteMode({ showFileAutocomplete, showCommandAutocomplete });
-  const isVisible = resolveAutocompleteIsVisible({
+  const canShowAutocomplete = resolveAutocompleteIsVisible({
     mode,
     canLoadCommands,
     serverId,
@@ -270,6 +270,8 @@ export function useAgentAutocomplete(input: UseAgentAutocompleteInput): AgentAut
     draftConfig: queryDraftConfig,
   });
 
+  const isVisible = canShowAutocomplete && !(mode === "command" && isCommandsLoading);
+
   const fileSuggestionsQuery = useQuery({
     queryKey: [
       "directorySuggestions",