Route mode-specific Search/Find tabs to the universal search (/?mode=…)

src/lib/mode-secondary-navigation.ts

@@ -1,4 +1,4 @@
-import { appModeHomeHref, type AppModeId } from "@/lib/app-modes";
+import { appModeHomeHref, appModeSelectionHref, type AppModeId } from "@/lib/app-modes";
 
 export type ModeSecondaryNavigationEntry = {
   id: string;
@@ -34,23 +34,23 @@ export const modeSecondaryNavigationRegistry = {
   forms: [],
   favourites: [],
   differentials: [
-    { id: "search", label: "Search", href: appModeHomeHref("differentials", { focus: true }) },
+    { id: "search", label: "Search", href: appModeSelectionHref("differentials", { focus: true }) },
     { id: "diagnoses", label: "Diagnoses", href: "/differentials/diagnoses" },
     { id: "presentations", label: "Presentations", href: "/differentials/presentations" },
     { id: "compare", label: "Compare", href: "/differentials/compare" },
   ],
   dsm: [
-    { id: "search", label: "Search", href: appModeHomeHref("dsm", { focus: true }) },
+    { id: "search", label: "Search", href: appModeSelectionHref("dsm", { focus: true }) },
     { id: "compare", label: "Compare", href: "/dsm/compare" },
   ],
   specifiers: [
-    { id: "search", label: "Find", href: appModeHomeHref("specifiers", { focus: true }) },
+    { id: "search", label: "Find", href: appModeSelectionHref("specifiers", { focus: true }) },
     { id: "builder", label: "Build", href: "/specifiers/builder" },
     { id: "compare", label: "Compare", href: "/specifiers/compare" },
     { id: "map", label: "Map", href: "/specifiers/map" },
   ],
   formulation: [
-    { id: "search", label: "Find", href: appModeHomeHref("formulation", { focus: true }) },
+    { id: "search", label: "Find", href: appModeSelectionHref("formulation", { focus: true }) },
     { id: "builder", label: "Build", href: "/formulation/builder" },
     { id: "compare", label: "Compare", href: "/formulation/compare" },
     { id: "map", label: "Map", href: "/formulation/map" },
@@ -252,10 +252,9 @@ export function modeSecondaryNavigationHref(params: {
 
   if (modeId === "differentials") {
     const entries: Array<readonly [string, string]> = query ? [["q", query]] : [];
-    // Returning to Search with a carried query must reopen the results view
-    // (`run=1`), not the empty mode home — even when the previous tab lacked run.
-    if (itemId === "search" && query) entries.push(["run", "1"]);
-    else if (itemId === "search" && currentSearchParams.get("run") === "1") entries.push(["run", "1"]);
+    // Search now returns to the shared universal composer. Keep a prior query as
+    // an editable draft, but deliberately drop `run=1`: that flag would submit
+    // immediately and the legacy redirect would send the user back here.
     // Compare (and other in-mode tabs) reuse URL-backed selection so ticks on
     // search survive ModeNav handoff without a second client store.
     if (currentSearchParams.get("ids")) {
@@ -267,7 +266,7 @@ export function modeSecondaryNavigationHref(params: {
   if (modeId === "dsm") {
     if (itemId === "search" && query) {
       return navigationHrefWithParams(
-        appModeHomeHref("dsm", { query, focus: true, run: currentSearchParams.get("run") === "1" }),
+        appModeSelectionHref("dsm", { query, focus: true }),
         currentSearchParams.get("ids") ? [["ids", currentSearchParams.get("ids") ?? ""]] : [],
       );
     }

tests/mode-secondary-navigation.test.ts

@@ -28,6 +28,17 @@ const expectedLabels: Record<AppModeId, string[]> = {
   factsheets: ["Topics", "Search"],
 };
 
+describe("shared search destinations", () => {
+  it.each([
+    ["differentials", "/?mode=differentials&focus=1"],
+    ["dsm", "/?mode=dsm&focus=1"],
+    ["specifiers", "/?mode=specifiers&focus=1"],
+    ["formulation", "/?mode=formulation&focus=1"],
+  ] as const)("routes the %s search tab to universal search with its mode selected", (modeId, href) => {
+    expect(modeSecondaryNavigationRegistry[modeId][0]).toMatchObject({ id: "search", href });
+  });
+});
+
 const cleanLandingPath: Record<AppModeId, string> = {
   answer: "/",
   documents: "/",
@@ -145,6 +156,15 @@ describe("mode secondary navigation registry", () => {
   });
 
   it("translates compatible workflow selection state into each destination URL", () => {
+    expect(
+      modeSecondaryNavigationHref({
+        modeId: "dsm",
+        itemId: "search",
+        href: "/?mode=dsm&focus=1",
+        currentSearchParams: new URLSearchParams("q=bipolar&run=1&ids=one%2Ctwo"),
+      }),
+    ).toBe("/?mode=dsm&q=bipolar&focus=1&ids=one%2Ctwo");
+
     expect(
       modeSecondaryNavigationHref({
         modeId: "specifiers",
@@ -181,16 +201,17 @@ describe("mode secondary navigation registry", () => {
       }),
     ).toBe("/differentials/presentations?q=confusion&ids=delirium%2Cdementia");
 
-    // Search restores the last query and re-opens results even when the prior
-    // tab URL did not carry run=1 (e.g. Diagnoses / Presentations browse).
+    // Search returns to the universal composer with the mode selected and the
+    // prior query as a draft. It must not carry run=1, which would re-open the
+    // old mode-owned results route through the legacy redirect.
     expect(
       modeSecondaryNavigationHref({
         modeId: "differentials",
         itemId: "search",
-        href: "/differentials?focus=1",
-        currentSearchParams: new URLSearchParams("q=confusion&ids=delirium"),
+        href: "/?mode=differentials&focus=1",
+        currentSearchParams: new URLSearchParams("q=confusion&run=1&ids=delirium"),
       }),
-    ).toBe("/differentials?focus=1&q=confusion&run=1&ids=delirium");
+    ).toBe("/?mode=differentials&focus=1&q=confusion&ids=delirium");
 
     // Search is the CURRENT tab on /factsheets/search, so its own link must not
     // reset what you are looking at. `run` is carried with the query because

tests/page-secondary-navigation.dom.test.tsx

@@ -95,6 +95,7 @@ describe("PageSecondaryNavigation", () => {
     expect(bar).toHaveAttribute("aria-label", "Specifiers pages");
     expect(screen.getByRole("link", { name: "Compare" })).toHaveAttribute("aria-current", "page");
     expect(screen.getByRole("link", { name: "Build" })).toHaveAttribute("href", "/specifiers/builder");
+    expect(screen.getByRole("link", { name: "Find" })).toHaveAttribute("href", "/?mode=specifiers&focus=1");
     // Registry order is load-bearing: only the first two slots survive the
     // narrowest band, so Find and Build must be the ones that stay.
     expect([...bar.querySelectorAll("li a")].map((link) => link.textContent)).toEqual([