Files
cloudflare__vinext/tests/app-page-request.test.ts
T
Nathan Nguyen 301418a3f1 perf(app-router): defer layout, template and boundary modules to first request (#2145)
* perf(app-router): defer layout, template and boundary modules to first request

The generated RSC entry statically imported every route's layout, template,
loading/error/not-found/forbidden/unauthorized boundary and parallel-slot
module at the top level. On a cold isolate — and on the dev server's first
request — that eagerly evaluated the whole app's segment tree, including
routes never visited in that lifetime. Page and route-handler modules were
already lazy; the surrounding segment modules were not.

Emit those modules as lazy `() => import()` loaders paired with `null`
placeholders in the manifest, and hydrate them onto the route's synchronous
fields in `ensureAppRouteModulesLoaded` before any read (extended from
page/handler to layouts, templates, boundaries and parallel-slot modules).
Intercept layouts hydrate via the dedicated `loadAppInterceptLayouts` because
they live on the match object, not the route. Every reader already runs behind
`ensureAppRouteModulesLoaded` (handler dispatch and `buildPageElements`) or the
intercept resolvers, so no synchronous module field is read before hydration.

The shared intercept `interceptLayouts` arrays keep their `readonly` public
types; the loader is their sole writer and fills slots through one
boundary-local cast, so route metadata stays immutable to callers.

Dev cold start is unchanged on page-heavy apps — pages were already lazy — but
on a boundary-heavy app (80 independent sections, each with
layout+template+error+loading+not-found) first-request module compile drops
704ms -> 534ms (~24%) and time-to-first-200 1917ms -> 1665ms. The saving scales
with the number of unrelated segments deferred.

* test(app-router): localize react max header font fixture

* fix(app-router): dedupe lazy intercept module loads

* fix(app-router): share intercept load state across matches

* docs(app-router): explain root layout loader reuse

---------

Co-authored-by: James <james@eli.cx>
2026-06-19 14:49:29 +01:00

675 lines
22 KiB
TypeScript

import { describe, expect, it, vi } from "vite-plus/test";
import { resolveAppPageSpecialError } from "../packages/vinext/src/server/app-page-execution.js";
import {
buildAppPageElement,
resolveAppPageActionRerenderTarget,
resolveAppPageIntercept,
resolveAppPageInterceptMatch,
resolveAppPageGenerateStaticParamsSources,
validateAppPageDynamicParams,
} from "../packages/vinext/src/server/app-page-request.js";
describe("app page request helpers", () => {
it("returns 404 when dynamicParams=false receives unknown params", async () => {
const clearRequestContext = vi.fn();
const response = await validateAppPageDynamicParams({
clearRequestContext,
enforceStaticParamsOnly: true,
async generateStaticParams() {
return [{ slug: "known-post" }];
},
isDynamicRoute: true,
params: { slug: "missing-post" },
});
expect(response?.status).toBe(404);
await expect(response?.text()).resolves.toBe("This page could not be found");
expect(clearRequestContext).toHaveBeenCalledTimes(1);
});
it("returns 404 when dynamicParams=false has no static params sources", async () => {
const clearRequestContext = vi.fn();
const response = await validateAppPageDynamicParams({
clearRequestContext,
enforceStaticParamsOnly: true,
generateStaticParams: undefined,
isDynamicRoute: true,
params: { slug: "anything" },
});
expect(response?.status).toBe(404);
await expect(response?.text()).resolves.toBe("This page could not be found");
expect(clearRequestContext).toHaveBeenCalledTimes(1);
});
it("allows matching static params, including nested parent params", async () => {
const clearRequestContext = vi.fn();
const response = await validateAppPageDynamicParams({
clearRequestContext,
enforceStaticParamsOnly: true,
async generateStaticParams() {
return [{ item: "shoe" }];
},
isDynamicRoute: true,
params: { category: "fashion", item: "shoe" },
});
expect(response).toBeNull();
expect(clearRequestContext).not.toHaveBeenCalled();
});
it("requires every segment generateStaticParams source to allow the params", async () => {
const clearRequestContext = vi.fn();
const layoutGenerateStaticParams = async () => [{ category: "docs" }];
const pageGenerateStaticParams = async () => [{ slug: "intro" }];
const response = await validateAppPageDynamicParams({
clearRequestContext,
enforceStaticParamsOnly: true,
generateStaticParams: [layoutGenerateStaticParams, pageGenerateStaticParams],
isDynamicRoute: true,
params: { category: "docs", slug: "missing" },
});
expect(response?.status).toBe(404);
expect(clearRequestContext).toHaveBeenCalledTimes(1);
});
it("passes parent-only params to each generateStaticParams source", async () => {
const clearRequestContext = vi.fn();
const categoryGenerateStaticParams = vi.fn(() => [{ category: "docs" }]);
const itemGenerateStaticParams = vi.fn(
({ params }: { params: Record<string, string | string[]> }) => {
if (params.category !== "docs" || params.slug !== undefined) {
return [];
}
return [{ slug: "intro" }];
},
);
const response = await validateAppPageDynamicParams({
clearRequestContext,
enforceStaticParamsOnly: true,
generateStaticParams: resolveAppPageGenerateStaticParamsSources({
layouts: [null, { generateStaticParams: categoryGenerateStaticParams }],
layoutTreePositions: [0, 1],
page: { generateStaticParams: itemGenerateStaticParams },
routeSegments: ["[category]", "[slug]"],
}),
isDynamicRoute: true,
params: { category: "docs", slug: "intro" },
});
expect(response).toBeNull();
expect(clearRequestContext).not.toHaveBeenCalled();
expect(categoryGenerateStaticParams).toHaveBeenCalledWith({ params: {} });
expect(itemGenerateStaticParams).toHaveBeenCalledWith({ params: { category: "docs" } });
});
// Ported from Next.js: packages/next/src/build/static-paths/app.test.ts
// https://github.com/vercel/next.js/blob/canary/packages/next/src/build/static-paths/app.test.ts
it("throws when generateStaticParams throws", async () => {
const error = new Error("boom");
await expect(
validateAppPageDynamicParams({
clearRequestContext() {},
enforceStaticParamsOnly: true,
async generateStaticParams() {
throw error;
},
isDynamicRoute: true,
params: { slug: "post" },
}),
).rejects.toThrow(error);
});
// Ported from Next.js: packages/next/src/build/static-paths/app.test.ts
// https://github.com/vercel/next.js/blob/canary/packages/next/src/build/static-paths/app.test.ts
it("throws when generateStaticParams rejects", async () => {
const error = new Error("async boom");
await expect(
validateAppPageDynamicParams({
clearRequestContext() {},
enforceStaticParamsOnly: true,
async generateStaticParams() {
return Promise.reject(error);
},
isDynamicRoute: true,
params: { slug: "post" },
}),
).rejects.toThrow(error);
});
// Ported from Next.js: packages/next/src/build/static-paths/app.test.ts
// https://github.com/vercel/next.js/blob/canary/packages/next/src/build/static-paths/app.test.ts
it("does not check remaining sources when an earlier generateStaticParams source throws", async () => {
const clearRequestContext = vi.fn();
const throwsSource = vi.fn(() => {
throw new Error("source 1 failed");
});
const rejectsSource = vi.fn(async () => [{ slug: "other" }]);
await expect(
validateAppPageDynamicParams({
clearRequestContext,
enforceStaticParamsOnly: true,
generateStaticParams: [throwsSource, rejectsSource],
isDynamicRoute: true,
params: { slug: "target" },
}),
).rejects.toThrow("source 1 failed");
expect(clearRequestContext).not.toHaveBeenCalled();
expect(throwsSource).toHaveBeenCalledTimes(1);
expect(rejectsSource).not.toHaveBeenCalled();
});
it("returns 404 when generateStaticParams excludes the requested params", async () => {
const clearRequestContext = vi.fn();
const response = await validateAppPageDynamicParams({
clearRequestContext,
enforceStaticParamsOnly: true,
generateStaticParams: async () => [{ slug: "other" }],
isDynamicRoute: true,
params: { slug: "target" },
});
expect(response?.status).toBe(404);
expect(clearRequestContext).toHaveBeenCalledTimes(1);
});
it("renders intercepted source routes on RSC navigations", async () => {
const setNavigationContext = vi.fn();
const buildPageElementMock = vi.fn(async () => ({ type: "intercept-element" }));
const renderInterceptResponse = vi.fn(async () => new Response("intercepted"));
const currentRoute = { params: ["id"], pattern: "/photos/[id]" };
const sourceRoute = { params: [], pattern: "/feed" };
const result = await resolveAppPageIntercept({
buildPageElement: buildPageElementMock,
cleanPathname: "/photos/123",
currentRoute,
findIntercept() {
return {
matchedParams: { id: "123" },
page: { default: "modal-page" },
slotKey: "modal@app/feed/@modal",
sourceRouteIndex: 0,
};
},
getRouteParamNames(route) {
return route.params;
},
getSourceRoute() {
return sourceRoute;
},
isRscRequest: true,
resolveNavigationParams(_route, params) {
return { ...params, catchAll: ["photos", "123"] };
},
renderInterceptResponse,
searchParams: new URLSearchParams("from=feed"),
setNavigationContext,
toInterceptOpts(intercept) {
return {
interceptPage: intercept.page,
interceptParams: intercept.matchedParams,
interceptSlotKey: intercept.slotKey,
};
},
});
expect(result.interceptOpts).toBeUndefined();
expect(result.response).toBeInstanceOf(Response);
expect(setNavigationContext).toHaveBeenCalledWith({
params: { id: "123", catchAll: ["photos", "123"] },
pathname: "/photos/123",
searchParams: new URLSearchParams("from=feed"),
});
expect(buildPageElementMock).toHaveBeenCalledWith(
sourceRoute,
{},
{
interceptPage: { default: "modal-page" },
interceptParams: { id: "123" },
interceptSlotKey: "modal@app/feed/@modal",
},
new URLSearchParams("from=feed"),
undefined,
);
expect(renderInterceptResponse).toHaveBeenCalledTimes(1);
});
it("returns intercept opts when the source route is the current route", async () => {
const currentRoute = { params: ["id"], pattern: "/photos/[id]" };
const result = await resolveAppPageIntercept({
async buildPageElement() {
throw new Error("should not build a separate intercept element");
},
cleanPathname: "/photos/123",
currentRoute,
findIntercept() {
return {
matchedParams: { id: "123" },
page: { default: "modal-page" },
slotKey: "modal@app/feed/@modal",
sourceRouteIndex: 0,
};
},
getRouteParamNames(route) {
return route.params;
},
getSourceRoute() {
return currentRoute;
},
isRscRequest: true,
resolveNavigationParams(_route, params) {
return params;
},
async renderInterceptResponse() {
throw new Error("should not render a separate intercept response");
},
searchParams: new URLSearchParams(),
setNavigationContext() {},
toInterceptOpts(intercept) {
return {
interceptPage: intercept.page,
interceptParams: intercept.matchedParams,
interceptSlotKey: intercept.slotKey,
};
},
});
expect(result.response).toBeNull();
expect(result.interceptOpts).toEqual({
interceptPage: { default: "modal-page" },
interceptParams: { id: "123" },
interceptSlotKey: "modal@app/feed/@modal",
});
});
it("returns special-error responses from page builds", async () => {
const result = await buildAppPageElement({
async buildPageElement() {
throw { digest: "NEXT_REDIRECT;replace;%2Ftarget;308" };
},
async renderErrorBoundaryPage() {
throw new Error("should not render boundary for special errors");
},
async renderSpecialError(specialError) {
return new Response(`${specialError.kind}:${specialError.statusCode}`);
},
resolveSpecialError: resolveAppPageSpecialError,
});
expect(result.element).toBeNull();
await expect(result.response?.text()).resolves.toBe("redirect:308");
});
it("falls back to error boundaries for non-special build failures", async () => {
const boundaryResponse = new Response("boundary", { status: 200 });
const result = await buildAppPageElement({
async buildPageElement() {
throw new Error("boom");
},
async renderErrorBoundaryPage(error) {
expect(error).toBeInstanceOf(Error);
return boundaryResponse;
},
async renderSpecialError() {
throw new Error("should not handle as a special error");
},
resolveSpecialError: resolveAppPageSpecialError,
});
expect(result.element).toBeNull();
expect(result.response).toBe(boundaryResponse);
});
it("prefers an already-thrown page notFound over a later metadata notFound", async () => {
// Ported from Next.js: test/e2e/app-dir/metadata-thrown/metadata-thrown.test.ts
// https://github.com/vercel/next.js/blob/canary/test/e2e/app-dir/metadata-thrown/metadata-thrown.test.ts
const pageError = { digest: "NEXT_HTTP_ERROR_FALLBACK;404" };
const metadataError = { digest: "NEXT_HTTP_ERROR_FALLBACK;404", fromMetadata: true };
const result = await buildAppPageElement({
async buildPageElement() {
await new Promise((resolve) => setTimeout(resolve, 0));
throw metadataError;
},
async probePageSpecialError() {
return resolveAppPageSpecialError(pageError);
},
async renderErrorBoundaryPage() {
throw new Error("should not render boundary for special errors");
},
async renderSpecialError(specialError) {
return new Response(specialError.fromMetadata ? "metadata" : "page", {
status: specialError.statusCode,
});
},
resolveSpecialError(error) {
const specialError = resolveAppPageSpecialError(error);
if (specialError && error === metadataError) {
specialError.fromMetadata = true;
}
return specialError;
},
});
expect(result.element).toBeNull();
expect(result.response?.status).toBe(404);
await expect(result.response?.text()).resolves.toBe("page");
});
});
describe("resolveAppPageInterceptMatch", () => {
const sourceRoute = { params: [], pattern: "/feed" };
const currentRoute = { params: ["id"], pattern: "/photos/[id]" };
const toInterceptOpts = (intercept: {
matchedParams: Record<string, string | string[]>;
page: unknown;
slotKey: string;
}) => ({
interceptPage: intercept.page,
interceptParams: intercept.matchedParams,
interceptSlotKey: intercept.slotKey,
});
it("returns null on non-RSC requests", async () => {
const result = await resolveAppPageInterceptMatch({
cleanPathname: "/photos/123",
currentRoute,
findIntercept() {
throw new Error("should not look up intercepts on non-RSC requests");
},
getRouteParamNames: (route) => route.params,
getSourceRoute: () => sourceRoute,
isRscRequest: false,
toInterceptOpts,
});
expect(result).toBeNull();
});
it("returns null when findIntercept returns nothing", async () => {
const result = await resolveAppPageInterceptMatch({
cleanPathname: "/photos/123",
currentRoute,
findIntercept: () => null,
getRouteParamNames: (route) => route.params,
getSourceRoute: () => sourceRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result).toBeNull();
});
it("returns null when the source route is the current route", async () => {
const result = await resolveAppPageInterceptMatch({
cleanPathname: "/photos/123",
currentRoute,
findIntercept: () => ({
matchedParams: { id: "123" },
page: { default: "modal-page" },
slotKey: "modal@app/photos/@modal",
sourceRouteIndex: 0,
}),
getRouteParamNames: (route) => route.params,
getSourceRoute: () => currentRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result).toBeNull();
});
it("returns sourceRoute, sourceParams, matchedParams, and interceptOpts when an intercept applies", async () => {
const matchedParams = { id: "123" };
const intercept = {
matchedParams,
page: { default: "modal-page" },
slotKey: "modal@app/feed/@modal",
sourceRouteIndex: 0,
};
const result = await resolveAppPageInterceptMatch({
cleanPathname: "/photos/123",
currentRoute,
findIntercept: () => intercept,
getRouteParamNames: (route) => route.params,
getSourceRoute: () => sourceRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result).not.toBeNull();
expect(result?.sourceRoute).toBe(sourceRoute);
expect(result?.matchedParams).toBe(matchedParams);
// sourceParams keeps only the params declared by the source route.
// /feed has no dynamic params, so the slice is empty.
expect(result?.sourceParams).toEqual({});
expect(result?.interceptOpts).toEqual(toInterceptOpts(intercept));
});
it("deduplicates concurrent intercept page and layout loads", async () => {
const interceptPage = { default: "modal-page" };
const interceptLayout = { default: "modal-layout" };
const __pageLoader = vi.fn(async () => interceptPage);
const __loadInterceptLayout = vi.fn(async () => interceptLayout);
const sharedLoadState = {
page: null as unknown,
pageLoading: null as Promise<unknown> | null,
interceptLayoutsLoading: null as Promise<readonly unknown[]> | null,
};
const intercept = {
interceptLayouts: [null],
__loadInterceptLayouts: [__loadInterceptLayout],
matchedParams: { id: "123" },
page: null,
__pageLoader,
__loadState: sharedLoadState,
slotKey: "modal@app/feed/@modal",
sourceRouteIndex: 0,
};
const options = {
cleanPathname: "/photos/123",
currentRoute,
findIntercept: () => ({ ...intercept, page: sharedLoadState.page }),
getRouteParamNames: (route: { params: string[] }) => route.params,
getSourceRoute: () => sourceRoute,
isRscRequest: true,
toInterceptOpts,
};
await Promise.all([
resolveAppPageInterceptMatch(options),
resolveAppPageInterceptMatch(options),
]);
expect(__pageLoader).toHaveBeenCalledTimes(1);
expect(__loadInterceptLayout).toHaveBeenCalledTimes(1);
expect(sharedLoadState.page).toBe(interceptPage);
expect(intercept.interceptLayouts).toEqual([interceptLayout]);
});
it("slices source params down to the source route's declared params", async () => {
const categorySourceRoute = { params: ["category"], pattern: "/feed/[category]" };
const matchedParams = { category: "nature", id: "123" };
const result = await resolveAppPageInterceptMatch({
cleanPathname: "/photos/123",
currentRoute,
findIntercept: () => ({
matchedParams,
page: { default: "modal-page" },
slotKey: "modal@app/feed/[category]/@modal",
sourceRouteIndex: 0,
}),
getRouteParamNames: (route) => route.params,
getSourceRoute: () => categorySourceRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result?.sourceParams).toEqual({ category: "nature" });
expect(result?.matchedParams).toEqual({ category: "nature", id: "123" });
});
});
describe("resolveAppPageActionRerenderTarget", () => {
const sourceRoute = { params: [], pattern: "/feed" };
const currentRoute = { params: ["id"], pattern: "/photos/[id]" };
const toInterceptOpts = (intercept: {
matchedParams: Record<string, string | string[]>;
page: unknown;
slotKey: string;
}) => ({
interceptPage: intercept.page,
interceptParams: intercept.matchedParams,
interceptSlotKey: intercept.slotKey,
});
it("falls through to the current route on non-RSC requests", async () => {
const result = await resolveAppPageActionRerenderTarget({
cleanPathname: "/photos/123",
currentParams: { id: "123" },
currentRoute,
findIntercept() {
throw new Error("should not look up intercepts on non-RSC requests");
},
getRouteParamNames: (route) => route.params,
getSourceRoute: () => sourceRoute,
isRscRequest: false,
toInterceptOpts,
});
expect(result).toEqual({
interceptOpts: undefined,
navigationParams: { id: "123" },
params: { id: "123" },
route: currentRoute,
});
});
it("falls through to the current route when no intercept matches", async () => {
const result = await resolveAppPageActionRerenderTarget({
cleanPathname: "/photos/123",
currentParams: { id: "123" },
currentRoute,
findIntercept: () => null,
getRouteParamNames: (route) => route.params,
getSourceRoute: () => sourceRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result).toEqual({
interceptOpts: undefined,
navigationParams: { id: "123" },
params: { id: "123" },
route: currentRoute,
});
});
it("looks up the intercept once when the source route is the current route", async () => {
const findIntercept = vi.fn(() => ({
matchedParams: { id: "123" },
page: { default: "modal-page" },
slotKey: "modal@app/feed/@modal",
sourceRouteIndex: 0,
}));
const result = await resolveAppPageActionRerenderTarget({
cleanPathname: "/photos/123",
currentParams: { id: "123" },
currentRoute,
findIntercept,
getRouteParamNames: (route) => route.params,
getSourceRoute: () => currentRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result).toEqual({
interceptOpts: {
interceptPage: { default: "modal-page" },
interceptParams: { id: "123" },
interceptSlotKey: "modal@app/feed/@modal",
},
navigationParams: { id: "123" },
params: { id: "123" },
route: currentRoute,
});
expect(findIntercept).toHaveBeenCalledTimes(1);
});
it("preserves current-route intercept opts when action rerender stays on the direct route", async () => {
const result = await resolveAppPageActionRerenderTarget({
cleanPathname: "/photos/123",
currentParams: { id: "123" },
currentRoute,
findIntercept: () => ({
matchedParams: { id: "123" },
page: { default: "modal-page" },
slotKey: "modal@app/feed/@modal",
sourceRouteIndex: 0,
}),
getRouteParamNames: (route) => route.params,
getSourceRoute: () => currentRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result).toEqual({
interceptOpts: {
interceptPage: { default: "modal-page" },
interceptParams: { id: "123" },
interceptSlotKey: "modal@app/feed/@modal",
},
navigationParams: { id: "123" },
params: { id: "123" },
route: currentRoute,
});
});
it("rerenders the intercepted source route when an intercept match applies", async () => {
const result = await resolveAppPageActionRerenderTarget({
cleanPathname: "/photos/123",
currentParams: { id: "123" },
currentRoute,
findIntercept: () => ({
matchedParams: { id: "123" },
page: { default: "modal-page" },
slotKey: "modal@app/feed/@modal",
sourceRouteIndex: 0,
}),
getRouteParamNames: (route) => route.params,
getSourceRoute: () => sourceRoute,
isRscRequest: true,
toInterceptOpts,
});
expect(result).toEqual({
interceptOpts: {
interceptPage: { default: "modal-page" },
interceptParams: { id: "123" },
interceptSlotKey: "modal@app/feed/@modal",
},
navigationParams: { id: "123" },
params: {},
route: sourceRoute,
});
});
});