Cache components manual

jest.setup.js

@@ -12,4 +12,5 @@ jest.mock("react", () => {
 // Override untable_cache method to avoid caching in tests
 jest.mock("next/cache", () => ({
     unstable_cache: (fn) => fn,
+    cacheLife: jest.fn(),
 }));

next.config.ts

@@ -4,6 +4,7 @@ const nextConfig: NextConfig = {
     reactStrictMode: true,
     reactCompiler: true,
     serverExternalPackages: ["libnpmdiff", "npm-package-arg", "pacote"],
+    cacheComponents: true,
 };
 
 export default nextConfig;

src/app/[...parts]/_page/BundlephobiaDiff.tsx

@@ -1,3 +1,4 @@
+import { cacheLife } from "next/cache";
 import bundlephobia from "^/lib/api/bundlephobia";
 import { Bundlephobia } from "^/lib/Services";
 import type SimplePackageSpec from "^/lib/SimplePackageSpec";
@@ -21,6 +22,11 @@ const BundlephobiaDiffInner = async ({
     a,
     b,
 }: BundlephobiaDiffProps) => {
+    "use cache";
+
+    // The shortest cacheLife that `bundlephobia` uses is hours, so we can use that here too.
+    cacheLife("hours");
+
     const { result, time } = await measuredPromise(bundlephobia(specs));
 
     if (result == null) {

src/app/[...parts]/_page/NpmDiff/NpmDiff.tsx

@@ -1,4 +1,5 @@
 import type { Options } from "libnpmdiff";
+import { cacheLife } from "next/cache";
 import { Suspense } from "react";
 import type { FileData } from "react-diff-view";
 import Stack from "^/components/ui/Stack";
@@ -18,6 +19,10 @@ export interface NpmDiffProps {
 }
 
 const NpmDiff = async ({ a, b, specs, options }: NpmDiffProps) => {
+    "use cache";
+
+    cacheLife("max");
+
     const diff = await npmDiff(specs, options);
 
     const files: FileData[] = gitDiffParse(diff);

src/app/[...parts]/_page/PackagephobiaDiff.tsx

@@ -1,3 +1,4 @@
+import { cacheLife } from "next/cache";
 import packagephobia from "^/lib/api/packagephobia";
 import { Packagephobia } from "^/lib/Services";
 import type SimplePackageSpec from "^/lib/SimplePackageSpec";
@@ -18,6 +19,11 @@ const PackagephobiaDiffInner = async ({
     a,
     b,
 }: PackagephobiaDiffProps) => {
+    "use cache";
+
+    // Cache for the shortest window that packagephobia is cached
+    cacheLife("hours");
+
     const { result, time } = await measuredPromise(packagephobia(specs));
 
     if (result == null) {

src/app/[...parts]/page.tsx

@@ -1,6 +1,6 @@
 import { type Metadata } from "next";
 import { redirect } from "next/navigation";
-import { type JSX } from "react";
+import { type JSX, Suspense } from "react";
 import { type ViewType } from "react-diff-view";
 import { createSimplePackageSpec } from "^/lib/createSimplePackageSpec";
 import { DEFAULT_DIFF_FILES_GLOB } from "^/lib/default-diff-files";
@@ -35,7 +35,7 @@ export async function generateMetadata({
     };
 }
 
-const DiffPage = async ({
+const DiffPageInner = async ({
     params,
     searchParams,
 }: DiffPageProps): Promise<JSX.Element> => {
@@ -108,4 +108,12 @@ const DiffPage = async ({
     }
 };
 
+const DiffPage = (props: DiffPageProps) => {
+    return (
+        <Suspense>
+            <DiffPageInner {...props} />
+        </Suspense>
+    );
+};
+
 export default DiffPage;

src/app/_layout/Header/Header.tsx

@@ -1,10 +1,10 @@
 import Link from "next/link";
-import { forwardRef, type HTMLAttributes } from "react";
+import { forwardRef, type HTMLAttributes, Suspense } from "react";
 import Heading from "^/components/ui/Heading";
 import { cx } from "^/lib/cva";
 import ColorModeToggle from "./ColorModeToggle";
 import GithubLink from "./GithubLink";
-import NavLink from "./NavLink";
+import NavLink, { NavLinkFallback } from "./NavLink";
 
 export interface HeaderProps extends HTMLAttributes<HTMLElement> {}
 
@@ -34,9 +34,23 @@ const Header = forwardRef<HTMLElement, HeaderProps>(
                 </Heading>
             </Link>
             <div className="flex items-center justify-end">
-                <NavLink href="/about">about</NavLink>
-                <span>/</span>
-                <NavLink href="/about/api">api</NavLink>
+                <Suspense
+                    fallback={
+                        <>
+                            <NavLinkFallback href="/about">
+                                about
+                            </NavLinkFallback>
+                            <span>/</span>
+                            <NavLinkFallback href="/about/api">
+                                api
+                            </NavLinkFallback>
+                        </>
+                    }
+                >
+                    <NavLink href="/about">about</NavLink>
+                    <span>/</span>
+                    <NavLink href="/about/api">api</NavLink>
+                </Suspense>
             </div>
         </nav>
     ),

src/app/_layout/Header/NavLink.tsx

@@ -52,4 +52,17 @@ const NavLink = forwardRef<HTMLAnchorElement, NavLinkProps>(function NavLink(
     );
 });
 
+export const NavLinkFallback = forwardRef<HTMLAnchorElement, NavLinkProps>(
+    function NavLinkFallback({ href = "", className, ...props }, ref) {
+        return (
+            <Link
+                href={href}
+                className={navLinkVariants({ className })}
+                {...props}
+                ref={ref}
+            />
+        );
+    },
+);
+
 export default NavLink;

src/app/about/api/page.tsx

@@ -1,4 +1,5 @@
 import type { Metadata } from "next";
+import { cacheLife } from "next/cache";
 import ExternalLink from "^/components/ExternalLink";
 import Code from "^/components/ui/Code";
 import Heading from "^/components/ui/Heading";
@@ -23,9 +24,11 @@ export const metadata: Metadata = {
     description: "API documentation for npm-diff.app",
 };
 
-// We need nodejs since we use Npm libs https://beta.nextjs.org/docs/api-reference/segment-config#runtime
-export const runtime = "nodejs";
 const AboutApiPage = async () => {
+    "use cache";
+
+    cacheLife("max");
+
     const specsOrVersions = splitParts(EXAMPLE_QUERY);
     const { canonicalSpecs: specs } = await destination(specsOrVersions);
 

src/app/api/-/versions/route.ts

@@ -2,8 +2,6 @@ import { NextResponse } from "next/server";
 import getVersionData from "^/lib/api/npm/getVersionData";
 import { type Version, VERSIONS_PARAMETER_PACKAGE } from "./types";
 
-export const runtime = "edge";
-
 export async function GET(request: Request) {
     const start = Date.now();
 

src/app/page.tsx

@@ -1,10 +1,15 @@
+import { cacheLife } from "next/cache";
 import fallback from "^/lib/autocomplete/fallback";
 import Intro from "./_page/Intro";
 import IndexPageClient from "./page.client";
 
 export interface IndexProps {}
 
 const IndexPage = async ({}: IndexProps) => {
+    "use cache";
+
+    cacheLife("max");
+
     const fallbackSuggestions = await fallback();
 
     return (

src/lib/api/bundlephobia/bundlephobia.ts

@@ -1,11 +1,16 @@
+import { cacheLife } from "next/cache";
 import npa from "npm-package-arg";
+import { USER_AGENT } from "../user-agent";
 import type BundlephobiaResponse from "./BundlephobiaResponse";
 import type BundlephobiaResults from "./BundlephobiaResults";
 
 async function getPackage(spec: string): Promise<BundlephobiaResponse | null> {
+    "use cache";
+
     const { scope } = npa(spec);
 
     if (scope === "@types") {
+        cacheLife("max");
         return null;
     }
 
@@ -14,18 +19,74 @@ async function getPackage(spec: string): Promise<BundlephobiaResponse | null> {
             `https://bundlephobia.com/api/size?package=${spec}`,
             {
                 signal: AbortSignal.timeout(7_500),
+                headers: {
+                    "User-Agent": USER_AGENT,
+                },
+                // Opt out of fetch-level caching, we have caching in function
+                cache: "no-store",
             },
         );
 
-        if (response.status !== 200) {
-            throw new Error(`${response.status} ${response.statusText}`);
-        }
+        if (response.status === 200) {
+            // If we succeed, cache as long as we're allowed
+            cacheLife("max");
+
+            const json: BundlephobiaResponse = await response.json();
+
+            return json;
+        } else if (response.status === 403) {
+            // Bundlephobia returns 403 forbidden for packages that are not supposed to be bundled.
+            // This is a stable, permanent behaviour, so we cache forever.
+            // For a list of packages; https://github.com/pastelsky/bundlephobia/blob/bundlephobia/server/config.js
+            cacheLife("max");
+
+            console.warn(`[${spec}] Bundlephobia returned 403 Forbidden`);
+
+            return null;
+        } else if (response.status === 404) {
+            // Package not found, cache for a while
+            cacheLife("hours");
+
+            console.warn(`[${spec}] Bundlephobia returned 404 Not Found`);
+
+            return null;
+        } else if (response.status === 500) {
+            // Server error, this is most likely because the package is too large or complex for Bundlephobia to handle.
+            // We don't want to retry too often, but we also don't want to cache forever in case the issue is resolved.
+            cacheLife("days");
 
-        const json: BundlephobiaResponse = await response.json();
+            console.error(
+                `[${spec}] Bundlephobia returned 500 Internal Server Error`,
+            );
 
-        return json;
+            return null;
+        } else {
+            // For other, unexpected statuses, we cache briefly and log the error.
+            cacheLife("hours");
+
+            console.error(
+                `[${spec}] Bundlephobia returned unexpected status: ${response.status} ${response.statusText}`,
+            );
+
+            return null;
+        }
     } catch (e) {
-        console.error(`[${spec}] Bundlephobia error:`, e);
+        if (e instanceof Error && e.name === "TimeoutError") {
+            // Timing out is typical for large or complex packages.
+            // We don't want to retry too often, but we also don't want to cache forever in case the issue is resolved.
+            cacheLife("days");
+
+            console.error(`[${spec}] Bundlephobia request timed out`);
+
+            return null;
+        } else {
+            // For other, unexpected errors, we cache briefly and log the error.
+            cacheLife("hours");
+
+            console.error(`[${spec}] Bundlephobia error:`, e);
+
+            return null;
+        }
     }
 
     return null;

src/lib/api/npm/getVersionData.ts

@@ -1,5 +1,4 @@
-import { unstable_cache } from "next/cache";
-import { cache } from "react";
+import { cacheLife } from "next/cache";
 import type SimplePackageSpec from "^/lib/SimplePackageSpec";
 import { simplePackageSpecToString } from "^/lib/SimplePackageSpec";
 import packument from "./packument";
@@ -17,9 +16,13 @@ export type VersionMap = {
     [version: string]: VersionData;
 };
 
-async function getVersionDataInner(
+async function getVersionData(
     spec: string | SimplePackageSpec,
 ): Promise<VersionMap> {
+    "use cache";
+
+    cacheLife("hours");
+
     const specString =
         typeof spec === "string" ? spec : simplePackageSpecToString(spec);
 
@@ -52,13 +55,4 @@ async function getVersionDataInner(
     return versionData;
 }
 
-const getVersionData =
-    // Cache for request de-dupe
-    cache(
-        // unstable cache to cache between requests (5 minute TTL)
-        unstable_cache(getVersionDataInner, ["versionData"], {
-            revalidate: 300,
-        }),
-    );
-
 export default getVersionData;