refactor!: overhaul externals support

examples/shiki/nitro.config.ts

@@ -2,7 +2,4 @@ import { defineConfig } from "nitro";
 
 export default defineConfig({
   serverDir: "./",
-  externals: {
-    inline: ["shiki/core"],
-  },
 });

examples/vite-ssr-solid/vite.config.mjs

@@ -7,7 +7,6 @@ export default defineConfig({
   esbuild: { jsx: "preserve", jsxImportSource: "solid-js" },
   environments: {
     ssr: {
-      resolve: { noExternal: true /* fixes tests */ },
       build: { rollupOptions: { input: "./src/entry-server.tsx" } },
     },
     client: {

examples/vite-ssr-vue-router/vite.config.mjs

@@ -5,9 +5,6 @@ import { nitro } from "nitro/vite";
 
 export default defineConfig((_env) => ({
   plugins: [patchVueExclude(vue(), /\?assets/), devtoolsJson(), nitro()],
-  nitro: {
-    noExternals: true,
-  },
   environments: {
     client: { build: { rollupOptions: { input: "./app/entry-client.ts" } } },
     ssr: { build: { rollupOptions: { input: "./app/entry-server.ts" } } },

package.json

@@ -49,8 +49,8 @@
     "release": "pnpm test && pnpm build && changelogen --release --prerelease --push",
     "stub": "obuild --stub",
     "test": "pnpm lint && pnpm test:types && pnpm test:rollup && pnpm test:rolldown",
-    "test:rollup": "NITRO_BUILDER=rollup pnpm vitest",
     "test:rolldown": "NITRO_BUILDER=rolldown pnpm vitest",
+    "test:rollup": "NITRO_BUILDER=rollup pnpm vitest",
     "test:types": "tsc --noEmit"
   },
   "resolutions": {
@@ -63,7 +63,6 @@
     "db0": "^0.3.4",
     "h3": "2.0.1-rc.5",
     "jiti": "^2.6.1",
-    "nf3": "^0.1.12",
     "ofetch": "^2.0.0-alpha.3",
     "ohash": "^2.0.11",
     "oxc-minify": "^0.101.0",
@@ -129,6 +128,7 @@
     "mime": "^4.1.0",
     "miniflare": "^4.20251128.0",
     "mlly": "^1.8.0",
+    "nf3": "^0.1.12",
     "nypm": "^0.6.2",
     "obuild": "^0.4.4",
     "pathe": "^2.0.3",
@@ -156,20 +156,24 @@
     "unctx": "^2.4.1",
     "unimport": "^5.5.0",
     "untyped": "^2.0.0",
-    "unwasm": "^0.5.1",
+    "unwasm": "^0.5.2",
     "vitest": "^4.0.15",
     "wrangler": "^4.51.0",
     "xml2js": "^0.6.2",
     "youch": "4.1.0-beta.13",
     "youch-core": "^0.3.3"
   },
   "peerDependencies": {
+    "nf3": ">=0.2",
     "rolldown": "*",
     "rollup": "^4",
     "vite": "^7",
     "xml2js": "^0.6.2"
   },
   "peerDependenciesMeta": {
+    "nf3": {
+      "optional": true
+    },
     "rolldown": {
       "optional": true
     },

src/build/config.ts

@@ -1,7 +1,7 @@
 import type { Nitro, NitroImportMeta } from "nitro/types";
-import { dirname } from "pathe";
 import { defineEnv } from "unenv";
-import { pkgDir, runtimeDependencies, presetsDir } from "nitro/meta";
+import { pkgDir } from "nitro/meta";
+import { pathRegExp, toPathRegExp } from "../utils/regex.ts";
 
 export type BaseBuildConfig = ReturnType<typeof baseBuildConfig>;
 
@@ -33,29 +33,6 @@ export function baseBuildConfig(nitro: Nitro) {
     ...nitro.options.replace,
   };
 
-  const noExternal: (string | RegExp | ((id: string) => boolean))[] = [
-    "#",
-    "~",
-    "@/",
-    "~~",
-    "@@/",
-    "virtual:",
-    "nitro",
-    pkgDir,
-    nitro.options.serverDir,
-    nitro.options.buildDir,
-    dirname(nitro.options.entry),
-    ...(nitro.options.wasm === false
-      ? []
-      : [(id: string) => id.endsWith(".wasm")]),
-    ...nitro.options.handlers
-      .map((m) => m.handler)
-      .filter((i) => typeof i === "string"),
-    ...(nitro.options.dev || nitro.options.preset === "nitro-prerender"
-      ? []
-      : runtimeDependencies),
-  ].filter(Boolean) as string[];
-
   const { env } = defineEnv({
     nodeCompat: isNodeless,
     resolve: true,
@@ -67,8 +44,9 @@ export function baseBuildConfig(nitro: Nitro) {
 
   const aliases = resolveAliases({ ...env.alias });
 
+  const noExternal: RegExp[] = getNoExternals(nitro);
+
   return {
-    presetsDir,
     extensions,
     isNodeless,
     replacements,
@@ -78,6 +56,35 @@ export function baseBuildConfig(nitro: Nitro) {
   };
 }
 
+function getNoExternals(nitro: Nitro): RegExp[] {
+  const noExternal: RegExp[] = [
+    /\.[mc]?tsx?$/,
+    /^(?:[\0#~.]|virtual:)/,
+    new RegExp("^" + pathRegExp(pkgDir) + "(?!.*node_modules)"),
+    ...[
+      nitro.options.rootDir,
+      ...nitro.options.scanDirs.filter(
+        (dir) =>
+          dir.includes("node_modules") || !dir.startsWith(nitro.options.rootDir)
+      ),
+    ].map((dir) => new RegExp("^" + pathRegExp(dir) + "(?!.*node_modules)")),
+  ];
+
+  if (nitro.options.wasm !== false) {
+    noExternal.push(/\.wasm$/);
+  }
+
+  if (Array.isArray(nitro.options.noExternals)) {
+    noExternal.push(
+      ...nitro.options.noExternals
+        .filter(Boolean)
+        .map((item) => toPathRegExp(item as string | RegExp))
+    );
+  }
+
+  return noExternal.sort((a, b) => a.source.length - b.source.length);
+}
+
 export function resolveAliases(_aliases: Record<string, string>) {
   // Sort aliases from specific to general (ie. fs/promises before fs)
   const aliases = Object.fromEntries(

src/build/plugins.ts

@@ -1,19 +1,18 @@
-import type { Nitro, NodeExternalsOptions } from "nitro/types";
+import type { Nitro } from "nitro/types";
 import type { Plugin } from "rollup";
 import type { BaseBuildConfig } from "./config.ts";
-import { defu } from "defu";
+
+import { virtualTemplates } from "./virtual/_all.ts";
 import unimportPlugin from "unimport/unplugin";
-import { unwasm } from "unwasm/plugin";
 import replace from "@rollup/plugin-replace";
+import { unwasm } from "unwasm/plugin";
 import { routeMeta } from "./plugins/route-meta.ts";
 import { serverMain } from "./plugins/server-main.ts";
 import { virtual } from "./plugins/virtual.ts";
-import { rollupNodeFileTrace } from "nf3";
 import { nitroResolveIds } from "./plugins/resolve.ts";
 import { sourcemapMinify } from "./plugins/sourcemap-min.ts";
 import { raw } from "./plugins/raw.ts";
-
-import { virtualTemplates } from "./virtual/_all.ts";
+import { externals } from "./plugins/externals.ts";
 
 export function baseBuildPlugins(nitro: Nitro, base: BaseBuildConfig) {
   const plugins: Plugin[] = [];
@@ -49,36 +48,28 @@ export function baseBuildPlugins(nitro: Nitro, base: BaseBuildConfig) {
   nitro.vfs = virtualPlugin.api.modules;
   plugins.push(virtualPlugin);
 
-  // Replace Plugin
+  // Replace
   plugins.push(
     (replace as unknown as typeof replace.default)({
       preventAssignment: true,
       values: base.replacements,
     })
   );
 
-  // Externals Plugin
-  if (!nitro.options.noExternals) {
+  // Externals (require Node.js compatible resolution)
+  if (nitro.options.node && nitro.options.noExternals !== true) {
+    const isDevOrPrerender =
+      nitro.options.dev || nitro.options.preset === "nitro-prerender";
     plugins.push(
-      rollupNodeFileTrace(
-        defu(nitro.options.externals, {
-          outDir: nitro.options.output.serverDir,
-          moduleDirectories: nitro.options.nodeModulesDirs,
-          external: nitro.options.nodeModulesDirs,
-          inline: [...base.noExternal],
-          traceOptions: {
-            base: "/",
-            processCwd: nitro.options.rootDir,
-            exportsOnly: true,
-          },
-          traceAlias: {
-            "h3-nightly": "h3",
-            ...nitro.options.externals?.traceAlias,
-          },
-          exportConditions: nitro.options.exportConditions as string[],
-          writePackageJson: true,
-        } satisfies NodeExternalsOptions)
-      )
+      externals({
+        rootDir: nitro.options.rootDir,
+        conditions: nitro.options.exportConditions || ["default"],
+        exclude: [...base.noExternal],
+        include: isDevOrPrerender ? undefined : nitro.options.traceDeps,
+        trace: isDevOrPrerender
+          ? false
+          : { outDir: nitro.options.output.serverDir },
+      })
     );
   }