refactor: use slide confirmation for role changes

frontend/src/components/manage/ManageHousehold.jsx

@@ -69,6 +69,7 @@ export default function ManageHousehold() {
   const [singleUseMode, setSingleUseMode] = useState("UNLIMITED");
   const [pendingDecisionId, setPendingDecisionId] = useState(null);
   const [isLeaveModalOpen, setIsLeaveModalOpen] = useState(false);
+  const [pendingRoleChange, setPendingRoleChange] = useState(null);
 
   const isManager = ["owner", "admin"].includes(activeHousehold?.role);
   const isOwner = activeHousehold?.role === "owner";
@@ -277,15 +278,10 @@ export default function ManageHousehold() {
     }
   };
 
-  const handleUpdateRole = async (memberId, nextRole, memberName) => {
-    if (!nextRole) return;
+  const handleConfirmRoleChange = async () => {
+    if (!pendingRoleChange) return;
 
-    if (
-      nextRole === "owner" &&
-      !window.confirm(`Make ${memberName} the household owner? You will become an admin.`)
-    ) {
-      return;
-    }
+    const { memberId, nextRole, memberName } = pendingRoleChange;
 
     try {
       await updateMemberRole(activeHousehold.id, memberId, nextRole);
@@ -298,12 +294,19 @@ export default function ManageHousehold() {
       } else {
         toast.success("Updated member role", `Updated role for ${memberName} to ${nextRole}`);
       }
+      setPendingRoleChange(null);
     } catch (error) {
       const message = getApiErrorMessage(error, "Failed to update member role");
       toast.error("Update member role failed", `Update member role failed: ${message}`);
     }
   };
 
+  const handleUpdateRole = (memberId, nextRole, memberName) => {
+    if (!nextRole) return;
+
+    setPendingRoleChange({ memberId, nextRole, memberName });
+  };
+
   const handleRemoveMember = async (memberId, username) => {
     if (!confirm(`Remove ${username} from this household?`)) return;
 
@@ -640,6 +643,27 @@ export default function ManageHousehold() {
         onClose={() => setIsLeaveModalOpen(false)}
         onConfirm={handleLeaveHousehold}
       />
+
+      <ConfirmSlideModal
+        isOpen={Boolean(pendingRoleChange)}
+        title={
+          pendingRoleChange?.nextRole === "owner"
+            ? `Transfer ownership to ${pendingRoleChange?.memberName || "this member"}?`
+            : `Change ${pendingRoleChange?.memberName || "this member"} to ${pendingRoleChange?.nextRole || "member"}?`
+        }
+        description={
+          pendingRoleChange?.nextRole === "owner"
+            ? "Slide to confirm. They will become the household owner and you will become an admin."
+            : "Slide to confirm this household role change."
+        }
+        confirmLabel={
+          pendingRoleChange?.nextRole === "owner"
+            ? "Transfer Ownership"
+            : `Make ${pendingRoleChange?.nextRole === "admin" ? "Admin" : "Member"}`
+        }
+        onClose={() => setPendingRoleChange(null)}
+        onConfirm={handleConfirmRoleChange}
+      />
     </div>
   );
 }

frontend/tests/invite-link-management.spec.ts

@@ -23,6 +23,25 @@ async function mockConfig(page: import("@playwright/test").Page) {
   });
 }
 
+async function confirmSlide(page: import("@playwright/test").Page) {
+  const confirmModal = page.locator(".confirm-slide-modal");
+  await expect(confirmModal).toBeVisible();
+
+  const slider = confirmModal.locator(".confirm-slide-handle");
+  const track = confirmModal.locator(".confirm-slide-track");
+  const sliderBox = await slider.boundingBox();
+  const trackBox = await track.boundingBox();
+
+  if (!sliderBox || !trackBox) {
+    throw new Error("Confirm slide control was not measurable");
+  }
+
+  await page.mouse.move(sliderBox.x + sliderBox.width / 2, sliderBox.y + sliderBox.height / 2);
+  await page.mouse.down();
+  await page.mouse.move(trackBox.x + trackBox.width - 4, sliderBox.y + sliderBox.height / 2, { steps: 8 });
+  await page.mouse.up();
+}
+
 test("join household modal accepts invite links but rejects legacy invite codes", async ({ page }) => {
   await seedAuthStorage(page);
   await mockConfig(page);
@@ -285,15 +304,13 @@ test("household owner can transfer ownership from household settings", async ({
     });
   });
 
-  page.on("dialog", async (dialog) => {
-    await dialog.accept();
-  });
-
   await page.goto("/manage?tab=household");
 
   await expect(page.getByRole("button", { name: "Make Owner" })).toBeVisible();
 
   await page.getByRole("button", { name: "Make Owner" }).click();
+  await expect(page.getByText("Transfer ownership to nico-admin?")).toBeVisible();
+  await confirmSlide(page);
 
   await expect(page.locator(".action-toast.action-toast-success")).toContainText("Transferred household ownership");
   await expect(page.locator(".action-toast.action-toast-success")).toContainText("nico-admin");