pingdotgg · juliusmarminge · Apr 10, 2026 · Apr 10, 2026 · Apr 10, 2026 · Apr 10, 2026
diff --git a/apps/web/src/components/ChatView.browser.tsx b/apps/web/src/components/ChatView.browser.tsx
@@ -717,17 +717,30 @@ function createSnapshotWithPendingUserInput(): OrchestrationReadModel {
   };
 }
 
-function createSnapshotWithPlanFollowUpPrompt(): OrchestrationReadModel {
+function createSnapshotWithPlanFollowUpPrompt(options?: {
+  modelSelection?: { provider: "codex"; model: string };
+  planMarkdown?: string;
+}): OrchestrationReadModel {
   const snapshot = createSnapshotForTargetUser({
     targetMessageId: "msg-user-plan-follow-up-target" as MessageId,
     targetText: "plan follow-up thread",
   });
+  const modelSelection = options?.modelSelection ?? {
+    provider: "codex" as const,
+    model: "gpt-5",
+  };
+  const planMarkdown =
+    options?.planMarkdown ?? "# Follow-up plan\n\n- Keep the composer footer stable on resize.";
 
   return {
     ...snapshot,
+    projects: snapshot.projects.map((project) =>
+      project.id === PROJECT_ID ? { ...project, defaultModelSelection: modelSelection } : project,
+    ),
     threads: snapshot.threads.map((thread) =>
       thread.id === THREAD_ID
         ? Object.assign({}, thread, {
+            modelSelection,
             interactionMode: "plan",
             latestTurn: {
               turnId: "turn-plan-follow-up" as TurnId,
@@ -741,7 +754,7 @@ function createSnapshotWithPlanFollowUpPrompt(): OrchestrationReadModel {
               {
                 id: "plan-follow-up-browser-test",
                 turnId: "turn-plan-follow-up" as TurnId,
-                planMarkdown: "# Follow-up plan\n\n- Keep the composer footer stable on resize.",
+                planMarkdown,
                 implementedAt: null,
                 implementationThreadId: null,
                 createdAt: isoAt(1_002),
@@ -3720,8 +3733,9 @@ describe("ChatView timeline estimator parity (full app)", () => {
       );
       const initialModelPickerOffset =
         initialModelPicker.getBoundingClientRect().left - footer.getBoundingClientRect().left;
+      const initialImplementButton = await waitForButtonByText("Implement");
+      const initialImplementWidth = initialImplementButton.getBoundingClientRect().width;
 
-      await waitForButtonByText("Implement");
       await waitForElement(
         () =>
           document.querySelector<HTMLButtonElement>('button[aria-label="Implementation actions"]'),
@@ -3753,6 +3767,7 @@ describe("ChatView timeline estimator parity (full app)", () => {
 
           expect(Math.abs(implementRect.right - implementActionsRect.left)).toBeLessThanOrEqual(1);
           expect(Math.abs(implementRect.top - implementActionsRect.top)).toBeLessThanOrEqual(1);
+          expect(Math.abs(implementRect.width - initialImplementWidth)).toBeLessThanOrEqual(1);
           expect(Math.abs(compactModelPickerOffset - initialModelPickerOffset)).toBeLessThanOrEqual(
             1,
           );
@@ -3764,6 +3779,73 @@ describe("ChatView timeline estimator parity (full app)", () => {
     }
   });
 
+  it("keeps the wide desktop follow-up layout expanded when the footer still fits", async () => {
+    const mounted = await mountChatView({
+      viewport: WIDE_FOOTER_VIEWPORT,
+      snapshot: createSnapshotWithPlanFollowUpPrompt({
+        modelSelection: { provider: "codex", model: "gpt-5.3-codex-spark" },
+        planMarkdown:
+          "# Imaginary Long-Range Plan: T3 Code Adaptive Orchestration and Safe-Delay Execution Initiative",
+      }),
+    });
+
+    try {
+      await waitForButtonByText("Implement");
+
+      await vi.waitFor(
+        () => {
+          const footer = document.querySelector<HTMLElement>('[data-chat-composer-footer="true"]');
+          const actions = document.querySelector<HTMLElement>(
+            '[data-chat-composer-actions="right"]',
+          );
+
+          expect(footer?.dataset.chatComposerFooterCompact).toBe("false");
+          expect(actions?.dataset.chatComposerPrimaryActionsCompact).toBe("false");
+        },
+        { timeout: 8_000, interval: 16 },
+      );
+    } finally {
+      await mounted.cleanup();
+    }
+  });
+
+  it("compacts the footer when a wide desktop follow-up layout starts overflowing", async () => {
+    const mounted = await mountChatView({
+      viewport: WIDE_FOOTER_VIEWPORT,
+      snapshot: createSnapshotWithPlanFollowUpPrompt({
+        modelSelection: { provider: "codex", model: "gpt-5.3-codex-spark" },
+        planMarkdown:
+          "# Imaginary Long-Range Plan: T3 Code Adaptive Orchestration and Safe-Delay Execution Initiative",
+      }),
+    });
+
+    try {
+      await waitForButtonByText("Implement");
+
+      await mounted.setContainerSize({
+        width: 804,
+        height: WIDE_FOOTER_VIEWPORT.height,
+      });
+
+      await expectComposerActionsContained();
+
+      await vi.waitFor(
+        () => {
+          const footer = document.querySelector<HTMLElement>('[data-chat-composer-footer="true"]');
+          const actions = document.querySelector<HTMLElement>(
+            '[data-chat-composer-actions="right"]',
+          );
+
+          expect(footer?.dataset.chatComposerFooterCompact).toBe("true");
+          expect(actions?.dataset.chatComposerPrimaryActionsCompact).toBe("true");
+        },
+        { timeout: 8_000, interval: 16 },
+      );
+    } finally {
+      await mounted.cleanup();
+    }
+  });
+
   it("keeps the slash-command menu visible above the composer", async () => {
     const mounted = await mountChatView({
       viewport: DEFAULT_VIEWPORT,

diff --git a/apps/web/src/components/chat/ChatComposer.tsx b/apps/web/src/components/chat/ChatComposer.tsx
@@ -55,8 +55,6 @@ import {
   removeInlineTerminalContextPlaceholder,
 } from "../../lib/terminalContext";
 import {
-  resolveComposerFooterContentWidth,
-  shouldForceCompactComposerFooterForFit,
   shouldUseCompactComposerPrimaryActions,
   shouldUseCompactComposerFooter,
 } from "../composerFooterLayout";
@@ -646,9 +644,6 @@ export const ChatComposer = memo(
     const composerEditorRef = useRef<ComposerPromptEditorHandle>(null);
     const composerFormRef = useRef<HTMLFormElement>(null);
     const composerFormHeightRef = useRef(0);
-    const composerFooterRef = useRef<HTMLDivElement>(null);
-    const composerFooterLeadingRef = useRef<HTMLDivElement>(null);
-    const composerFooterActionsRef = useRef<HTMLDivElement>(null);
     const composerSelectLockRef = useRef(false);
     const composerMenuOpenRef = useRef(false);
     const composerMenuItemsRef = useRef<ComposerCommandItem[]>([]);
@@ -1017,31 +1012,17 @@ export const ChatComposer = memo(
       const measureComposerFormWidth = () => composerForm.clientWidth;
       const measureFooterCompactness = () => {
         const composerFormWidth = measureComposerFormWidth();
-        const heuristicFooterCompact = shouldUseCompactComposerFooter(composerFormWidth, {
+        const footerCompact = shouldUseCompactComposerFooter(composerFormWidth, {
           hasWideActions: composerFooterHasWideActions,
         });
-        const footer = composerFooterRef.current;
-        const footerStyle = footer ? window.getComputedStyle(footer) : null;
-        const footerContentWidth = resolveComposerFooterContentWidth({
-          footerWidth: footer?.clientWidth ?? null,
-          paddingLeft: footerStyle ? Number.parseFloat(footerStyle.paddingLeft) : null,
-          paddingRight: footerStyle ? Number.parseFloat(footerStyle.paddingRight) : null,
-        });
-        const fitInput = {
-          footerContentWidth,
-          leadingContentWidth: composerFooterLeadingRef.current?.scrollWidth ?? null,
-          actionsWidth: composerFooterActionsRef.current?.scrollWidth ?? null,
-        };
-        const nextFooterCompact =
-          heuristicFooterCompact || shouldForceCompactComposerFooterForFit(fitInput);
-        const nextPrimaryActionsCompact =
-          nextFooterCompact &&
+        const primaryActionsCompact =
+          footerCompact &&
           shouldUseCompactComposerPrimaryActions(composerFormWidth, {
             hasWideActions: composerFooterHasWideActions,
           });
         return {
-          primaryActionsCompact: nextPrimaryActionsCompact,
-          footerCompact: nextFooterCompact,
+          primaryActionsCompact,
+          footerCompact,
         };
       };
 
@@ -1795,23 +1776,14 @@ export const ChatComposer = memo(
               </div>
             ) : (
               <div
-                ref={composerFooterRef}
                 data-chat-composer-footer="true"
                 data-chat-composer-footer-compact={isComposerFooterCompact ? "true" : "false"}
                 className={cn(
                   "flex min-w-0 flex-nowrap items-center justify-between gap-2 overflow-visible px-2.5 pb-2.5 sm:px-3 sm:pb-3",
                   isComposerFooterCompact ? "gap-1.5" : "gap-2 sm:gap-0",
                 )}
               >
-                <div
-                  ref={composerFooterLeadingRef}
-                  className={cn(
-                    "flex min-w-0 flex-1 items-center",
-                    isComposerFooterCompact
-                      ? "gap-1 overflow-x-auto [scrollbar-width:none] [&::-webkit-scrollbar]:hidden"
-                      : "gap-1 overflow-x-auto [scrollbar-width:none] [&::-webkit-scrollbar]:hidden sm:min-w-max sm:overflow-visible",
-                  )}
-                >
+                <div className="flex min-w-0 flex-1 items-center gap-1 overflow-x-auto [scrollbar-width:none] [&::-webkit-scrollbar]:hidden">
                   <ProviderModelPicker
                     compact={isComposerFooterCompact}
                     provider={selectedProvider}
@@ -1865,7 +1837,6 @@ export const ChatComposer = memo(
 
                 {/* Right side: send / stop button */}
                 <div
-                  ref={composerFooterActionsRef}
                   data-chat-composer-actions="right"
                   data-chat-composer-primary-actions-compact={
                     isComposerPrimaryActionsCompact ? "true" : "false"

diff --git a/apps/web/src/components/chat/ComposerPrimaryActions.tsx b/apps/web/src/components/chat/ComposerPrimaryActions.tsx
@@ -140,7 +140,7 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
         <Button
           type="submit"
           size="sm"
-          className={cn("h-9 rounded-l-full rounded-r-none sm:h-8", compact ? "px-3" : "px-4")}
+          className="h-9 rounded-l-full rounded-r-none px-4 sm:h-8"
           disabled={isSendBusy || isConnecting}
         >
           {isConnecting || isSendBusy ? "Sending..." : "Implement"}

diff --git a/apps/web/src/components/composerFooterLayout.test.ts b/apps/web/src/components/composerFooterLayout.test.ts
@@ -4,9 +4,6 @@ import {
   COMPOSER_FOOTER_COMPACT_BREAKPOINT_PX,
   COMPOSER_FOOTER_WIDE_ACTIONS_COMPACT_BREAKPOINT_PX,
   COMPOSER_PRIMARY_ACTIONS_COMPACT_BREAKPOINT_PX,
-  measureComposerFooterOverflowPx,
-  resolveComposerFooterContentWidth,
-  shouldForceCompactComposerFooterForFit,
   shouldUseCompactComposerPrimaryActions,
   shouldUseCompactComposerFooter,
 } from "./composerFooterLayout";
@@ -56,99 +53,3 @@ describe("shouldUseCompactComposerPrimaryActions", () => {
     ).toBe(false);
   });
 });
-
-describe("measureComposerFooterOverflowPx", () => {
-  it("returns the overflow amount when content exceeds the footer width", () => {
-    expect(
-      measureComposerFooterOverflowPx({
-        footerContentWidth: 500,
-        leadingContentWidth: 340,
-        actionsWidth: 180,
-      }),
-    ).toBe(28);
-  });
-
-  it("returns zero when content fits", () => {
-    expect(
-      measureComposerFooterOverflowPx({
-        footerContentWidth: 500,
-        leadingContentWidth: 320,
-        actionsWidth: 160,
-      }),
-    ).toBe(0);
-  });
-});
-
-describe("shouldForceCompactComposerFooterForFit", () => {
-  it("stays expanded when content widths fit within the footer", () => {
-    expect(
-      shouldForceCompactComposerFooterForFit({
-        footerContentWidth: 500,
-        leadingContentWidth: 320,
-        actionsWidth: 160,
-      }),
-    ).toBe(false);
-  });
-
-  it("stays expanded when minor overflow can be recovered by compacting primary actions", () => {
-    expect(
-      shouldForceCompactComposerFooterForFit({
-        footerContentWidth: 500,
-        leadingContentWidth: 340,
-        actionsWidth: 180,
-      }),
-    ).toBe(false);
-  });
-
-  it("forces footer compact mode when action compaction would not recover enough space", () => {
-    expect(
-      shouldForceCompactComposerFooterForFit({
-        footerContentWidth: 500,
-        leadingContentWidth: 420,
-        actionsWidth: 220,
-      }),
-    ).toBe(true);
-  });
-
-  it("ignores incomplete measurements", () => {
-    expect(
-      shouldForceCompactComposerFooterForFit({
-        footerContentWidth: null,
-        leadingContentWidth: 340,
-        actionsWidth: 180,
-      }),
-    ).toBe(false);
-  });
-});
-
-describe("resolveComposerFooterContentWidth", () => {
-  it("subtracts horizontal padding from the measured footer width", () => {
-    expect(
-      resolveComposerFooterContentWidth({
-        footerWidth: 500,
-        paddingLeft: 10,
-        paddingRight: 10,
-      }),
-    ).toBe(480);
-  });
-
-  it("clamps negative widths to zero", () => {
-    expect(
-      resolveComposerFooterContentWidth({
-        footerWidth: 10,
-        paddingLeft: 8,
-        paddingRight: 8,
-      }),
-    ).toBe(0);
-  });
-
-  it("returns null when measurements are incomplete", () => {
-    expect(
-      resolveComposerFooterContentWidth({
-        footerWidth: null,
-        paddingLeft: 8,
-        paddingRight: 8,
-      }),
-    ).toBeNull();
-  });
-});
diff --git a/apps/web/src/components/composerFooterLayout.ts b/apps/web/src/components/composerFooterLayout.ts
@@ -2,8 +2,6 @@ export const COMPOSER_FOOTER_COMPACT_BREAKPOINT_PX = 620;
 export const COMPOSER_FOOTER_WIDE_ACTIONS_COMPACT_BREAKPOINT_PX = 780;
 export const COMPOSER_PRIMARY_ACTIONS_COMPACT_BREAKPOINT_PX =
   COMPOSER_FOOTER_WIDE_ACTIONS_COMPACT_BREAKPOINT_PX;
-const COMPOSER_FOOTER_CONTENT_GAP_PX = 8;
-const COMPOSER_PRIMARY_ACTIONS_COMPACT_RECOVERY_PX = 120;
 
 export function shouldUseCompactComposerFooter(
   width: number | null,
@@ -24,46 +22,3 @@ export function shouldUseCompactComposerPrimaryActions(
   }
   return width !== null && width < COMPOSER_PRIMARY_ACTIONS_COMPACT_BREAKPOINT_PX;
 }
-
-export function measureComposerFooterOverflowPx(input: {
-  footerContentWidth: number | null;
-  leadingContentWidth: number | null;
-  actionsWidth: number | null;
-}): number | null {
-  const footerContentWidth = input.footerContentWidth;
-  const leadingContentWidth = input.leadingContentWidth;
-  const actionsWidth = input.actionsWidth;
-  if (footerContentWidth === null || leadingContentWidth === null || actionsWidth === null) {
-    return null;
-  }
-  return Math.max(
-    0,
-    leadingContentWidth + actionsWidth + COMPOSER_FOOTER_CONTENT_GAP_PX - footerContentWidth,
-  );
-}
-
-export function shouldForceCompactComposerFooterForFit(input: {
-  footerContentWidth: number | null;
-  leadingContentWidth: number | null;
-  actionsWidth: number | null;
-}): boolean {
-  const overflowPx = measureComposerFooterOverflowPx(input);
-  if (overflowPx === null) {
-    return false;
-  }
-  return overflowPx > COMPOSER_PRIMARY_ACTIONS_COMPACT_RECOVERY_PX;
-}
-
-export function resolveComposerFooterContentWidth(input: {
-  footerWidth: number | null;
-  paddingLeft: number | null;
-  paddingRight: number | null;
-}): number | null {
-  const footerWidth = input.footerWidth;
-  const paddingLeft = input.paddingLeft;
-  const paddingRight = input.paddingRight;
-  if (footerWidth === null || paddingLeft === null || paddingRight === null) {
-    return null;
-  }
-  return Math.max(0, footerWidth - paddingLeft - paddingRight);
-}