From 2fd388da08a152003a14745395fc0bbdc5472e9e Mon Sep 17 00:00:00 2001
From: Multica Eve <eve@devv.ai>
Date: Thu, 30 Apr 2026 14:32:51 +0800
Subject: [PATCH] fix: stabilize mobile issue detail layout (#1912)

Co-authored-by: Devv <devv@Devvs-Mac-mini.local>
---
 .../issues/components/issue-detail.test.tsx   | 21 ++++++
 .../views/issues/components/issue-detail.tsx  | 68 +++++++++++--------
 2 files changed, 61 insertions(+), 28 deletions(-)

diff --git a/packages/views/issues/components/issue-detail.test.tsx b/packages/views/issues/components/issue-detail.test.tsx
index a5652e9dd..691356326 100644
--- a/packages/views/issues/components/issue-detail.test.tsx
+++ b/packages/views/issues/components/issue-detail.test.tsx
@@ -3,6 +3,13 @@ import { describe, it, expect, vi, beforeEach } from "vitest";
 import { fireEvent, render, screen, waitFor } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import type { Issue, TimelineEntry } from "@multica/core/types";
+
+const mockViewport = vi.hoisted(() => ({ isMobile: false }));
+
+vi.mock("@multica/ui/hooks/use-mobile", () => ({
+  useIsMobile: () => mockViewport.isMobile,
+}));
+
 // useWorkspaceId() derives from useCurrentWorkspace (relative import inside
 // @multica/core/hooks.tsx). vi.mock("@multica/core/paths") only intercepts
 // the bare-specifier, not the internal relative import. Mock the hooks module
@@ -364,6 +371,7 @@ function renderIssueDetail(issueId = "issue-1") {
 describe("IssueDetail (shared)", () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    mockViewport.isMobile = false;
     // Default: issue loads successfully
     mockApiObj.getIssue.mockResolvedValue(mockIssue);
     mockApiObj.listTimeline.mockResolvedValue(mockTimeline);
@@ -425,6 +433,19 @@ describe("IssueDetail (shared)", () => {
     expect(screen.getByText("Due date")).toBeInTheDocument();
   });
 
+  it("uses a non-resizable layout with the sidebar sheet closed by default on mobile", async () => {
+    mockViewport.isMobile = true;
+
+    renderIssueDetail();
+
+    await waitFor(() => {
+      expect(screen.getByDisplayValue("Implement authentication")).toBeInTheDocument();
+    });
+
+    expect(screen.queryByTestId("panel-group")).not.toBeInTheDocument();
+    expect(screen.queryByText("Properties")).not.toBeInTheDocument();
+  });
+
   it("renders Details section with Created by and dates", async () => {
     renderIssueDetail();
 
diff --git a/packages/views/issues/components/issue-detail.tsx b/packages/views/issues/components/issue-detail.tsx
index cfc013721..da8f97380 100644
--- a/packages/views/issues/components/issue-detail.tsx
+++ b/packages/views/issues/components/issue-detail.tsx
@@ -177,14 +177,15 @@ export function IssueDetail({ issueId, onDelete, onDone, defaultSidebarOpen = tr
   });
   const sidebarRef = usePanelRef();
   const isMobile = useIsMobile();
-  const [sidebarOpen, setSidebarOpen] = useState(defaultSidebarOpen);
+  const [desktopSidebarOpen, setDesktopSidebarOpen] = useState(defaultSidebarOpen);
+  const [mobileSidebarOpen, setMobileSidebarOpen] = useState(false);
 
   useEffect(() => {
     if (isMobile) {
-      setSidebarOpen(false);
-      sidebarRef.current?.collapse();
+      setMobileSidebarOpen(false);
     }
   }, [isMobile]);
+  const sidebarOpen = isMobile ? mobileSidebarOpen : desktopSidebarOpen;
   const [propertiesOpen, setPropertiesOpen] = useState(true);
   const [detailsOpen, setDetailsOpen] = useState(true);
   const [parentIssueOpen, setParentIssueOpen] = useState(true);
@@ -307,6 +308,18 @@ export function IssueDetail({ issueId, onDelete, onDone, defaultSidebarOpen = tr
   const actions = useIssueActions(issue);
   const handleUpdateField = actions.updateField;
 
+  const handleToggleSidebar = useCallback(() => {
+    if (isMobile) {
+      setMobileSidebarOpen((open) => !open);
+      return;
+    }
+
+    const panel = sidebarRef.current;
+    if (!panel) return;
+    if (panel.isCollapsed()) panel.expand();
+    else panel.collapse();
+  }, [isMobile, sidebarRef]);
+
   if (loading) {
     return (
       <div className="flex flex-1 min-h-0 flex-col">
@@ -488,10 +501,8 @@ export function IssueDetail({ issueId, onDelete, onDone, defaultSidebarOpen = tr
     </div>
   );
 
-  return (
-    <ResizablePanelGroup orientation="horizontal" className="flex-1 min-h-0" defaultLayout={defaultLayout} onLayoutChanged={onLayoutChanged}>
-      <ResizablePanel id="content" minSize="50%">
-      <div className="flex h-full flex-col">
+  const detailContent = (
+    <div className="flex h-full min-w-0 flex-1 flex-col">
         <PageHeader className="gap-2 bg-background text-sm">
           <div className="flex flex-1 items-center gap-1.5 min-w-0">
             {workspace && (
@@ -572,16 +583,7 @@ export function IssueDetail({ issueId, onDelete, onDone, defaultSidebarOpen = tr
                     variant={sidebarOpen ? "secondary" : "ghost"}
                     size="icon-sm"
                     className={sidebarOpen ? "" : "text-muted-foreground"}
-                    onClick={() => {
-                      if (isMobile) {
-                        setSidebarOpen(!sidebarOpen);
-                      } else {
-                        const panel = sidebarRef.current;
-                        if (!panel) return;
-                        if (panel.isCollapsed()) panel.expand();
-                        else panel.collapse();
-                      }
-                    }}
+                    onClick={handleToggleSidebar}
                   >
                     <PanelRight />
                   </Button>
@@ -1000,9 +1002,27 @@ export function IssueDetail({ issueId, onDelete, onDone, defaultSidebarOpen = tr
         </div>
         </div>
       </div>
+  );
+
+  if (isMobile) {
+    return (
+      <div className="flex flex-1 min-h-0">
+        {detailContent}
+        <Sheet open={mobileSidebarOpen} onOpenChange={setMobileSidebarOpen}>
+          <SheetContent side="right" showCloseButton={false} className="w-[320px] overflow-y-auto p-4">
+            {sidebarContent}
+          </SheetContent>
+        </Sheet>
+      </div>
+    );
+  }
+
+  return (
+    <ResizablePanelGroup orientation="horizontal" className="flex-1 min-h-0" defaultLayout={defaultLayout} onLayoutChanged={onLayoutChanged}>
+      <ResizablePanel id="content" minSize="50%">
+        {detailContent}
       </ResizablePanel>
-      {!isMobile && <ResizableHandle />}
-      {!isMobile && (
+      <ResizableHandle />
       <ResizablePanel
         id="sidebar"
         defaultSize={defaultSidebarOpen ? 320 : 0}
@@ -1011,7 +1031,7 @@ export function IssueDetail({ issueId, onDelete, onDone, defaultSidebarOpen = tr
         collapsible
         groupResizeBehavior="preserve-pixel-size"
         panelRef={sidebarRef}
-        onResize={(size) => setSidebarOpen(size.inPixels > 0)}
+        onResize={(size) => setDesktopSidebarOpen(size.inPixels > 0)}
       >
       <div className="overflow-y-auto border-l h-full">
         <div className="p-4">
@@ -1019,14 +1039,6 @@ export function IssueDetail({ issueId, onDelete, onDone, defaultSidebarOpen = tr
         </div>
       </div>
       </ResizablePanel>
-      )}
-      {isMobile && (
-        <Sheet open={sidebarOpen} onOpenChange={setSidebarOpen}>
-          <SheetContent side="right" showCloseButton={false} className="w-[320px] overflow-y-auto p-4">
-            {sidebarContent}
-          </SheetContent>
-        </Sheet>
-      )}
     </ResizablePanelGroup>
   );
 }