feat: add support for custom source-extensions to watchers and bundlers

docs/1.docs/50.configuration.md

@@ -105,6 +105,26 @@ export default defineConfig({
 > [!NOTE]
 > The `srcDir` option is deprecated. Use `serverDir` instead.
 
+## Source extensions
+
+Nitro scans built-in JS and TS server files by default. Use `sourceExtensions` to add other script-like source extensions that your bundler can transform, such as `.civet` or `.res`.
+
+```ts [nitro.config.ts]
+import { defineConfig } from "nitro";
+
+export default defineConfig({
+  sourceExtensions: [".civet", ".res"],
+})
+```
+
+This affects server file scanning, entry resolution, generated route types, and development reload detection. Nitro still expects your builder or framework to provide the actual transform for the custom extension.
+
+If you also use custom source extensions for Nitro `modules`, those files must be supported by the current JS runtime. For example, with Civet you can register the loader before starting Nitro:
+
+```bash
+NODE_OPTIONS="--import @danielx/civet/register" pnpm dev
+```
+
 ## Environment variables
 
 Certain Nitro behaviors can be configured using environment variables:

src/build/config.ts

@@ -2,12 +2,16 @@ import type { Nitro, NitroImportMeta } from "nitro/types";
 import { defineEnv } from "unenv";
 import { pkgDir } from "nitro/meta";
 import { pathRegExp, toPathRegExp } from "../utils/regex.ts";
+import {
+  getSourceExtensionPattern,
+  getSourceExtensions,
+  TS_SOURCE_EXTENSIONS,
+} from "../utils/source-extensions.ts";
 
 export type BaseBuildConfig = ReturnType<typeof baseBuildConfig>;
 
 export function baseBuildConfig(nitro: Nitro) {
-  // prettier-ignore
-  const extensions: string[] = [".ts", ".mjs", ".js", ".json", ".node", ".tsx", ".jsx" ];
+  const extensions: string[] = [...getSourceExtensions(nitro.options), ".json", ".node"];
 
   const isNodeless = nitro.options.node === false;
 
@@ -66,8 +70,9 @@ export function baseBuildConfig(nitro: Nitro) {
 }
 
 function getNoExternals(nitro: Nitro): RegExp[] {
+  const extensionPattern = getSourceExtensionPattern(nitro.options, TS_SOURCE_EXTENSIONS);
   const noExternal: RegExp[] = [
-    /\.[mc]?tsx?$/,
+    new RegExp(String.raw`\.(?:${extensionPattern})$`),
     /^(?:[\0#~.]|virtual:)/,
     new RegExp("^" + pathRegExp(pkgDir) + "(?!.*node_modules)"),
     ...[

src/build/rolldown/dev.ts

@@ -4,6 +4,7 @@ import { watch as chokidarWatch } from "chokidar";
 import { basename, join } from "pathe";
 import { debounce } from "perfect-debounce";
 import { scanHandlers } from "../../scan.ts";
+import { getSourceExtensionPattern } from "../../utils/source-extensions.ts";
 import { writeTypes } from "../types.ts";
 import { formatCompatibilityDate } from "compatx";
 
@@ -40,7 +41,8 @@ export async function watchDev(nitro: Nitro, config: RolldownOptions) {
     }
   });
 
-  const serverEntryRe = /^server\.[mc]?[jt]sx?$/;
+  const sourceExtensionPattern = getSourceExtensionPattern(nitro.options);
+  const serverEntryRe = new RegExp(String.raw`^server(?:\.node)?\.(?:${sourceExtensionPattern})$`);
   const rootDirWatcher = chokidarWatch(nitro.options.rootDir, {
     ignoreInitial: true,
     depth: 0,

src/build/rollup/dev.ts

@@ -5,6 +5,7 @@ import { defu } from "defu";
 import { basename, join } from "pathe";
 import { debounce } from "perfect-debounce";
 import { scanHandlers } from "../../scan.ts";
+import { getSourceExtensionPattern } from "../../utils/source-extensions.ts";
 import { formatRollupError } from "./error.ts";
 import { writeTypes } from "../types.ts";
 import { formatCompatibilityDate } from "compatx";
@@ -42,7 +43,8 @@ export async function watchDev(nitro: Nitro, rollupConfig: RollupConfig) {
     }
   });
 
-  const serverEntryRe = /^server\.[mc]?[jt]sx?$/;
+  const sourceExtensionPattern = getSourceExtensionPattern(nitro.options);
+  const serverEntryRe = new RegExp(String.raw`^server(?:\.node)?\.(?:${sourceExtensionPattern})$`);
   const rootDirWatcher = chokidarWatch(nitro.options.rootDir, {
     ignoreInitial: true,
     depth: 0,

src/build/types.ts

@@ -12,6 +12,7 @@ import type { TSConfig } from "pkg-types";
 import type { JSValue } from "untyped";
 import { generateTypes, resolveSchema } from "untyped";
 import { toExports } from "unimport";
+import { getSourceExtensions, stripSourceExtension } from "../utils/source-extensions.ts";
 
 export async function writeTypes(nitro: Nitro) {
   const types: NitroTypes = {
@@ -29,10 +30,10 @@ export async function writeTypes(nitro: Nitro) {
     if (typeof mw.handler !== "string" || !mw.route) {
       continue;
     }
-    const relativePath = relative(
-      generatedTypesDir,
-      resolveNitroPath(mw.handler, nitro.options)
-    ).replace(/\.(js|mjs|cjs|ts|mts|cts|tsx|jsx)$/, "");
+    const relativePath = stripSourceExtension(
+      relative(generatedTypesDir, resolveNitroPath(mw.handler, nitro.options)),
+      nitro.options
+    );
 
     const method = mw.method || "default";
 
@@ -72,7 +73,7 @@ export async function writeTypes(nitro: Nitro) {
           from: nitro.options.rootDir,
           conditions: ["type", "node", "import"],
           suffixes: ["", "/index"],
-          extensions: [".mjs", ".cjs", ".js", ".mts", ".cts", ".ts"],
+          extensions: getSourceExtensions(nitro.options),
         });
         if (resolvedPath) {
           const { dir, name } = parseNodeModulePath(resolvedPath);

src/build/vite/dev.ts

@@ -13,6 +13,7 @@ import { join } from "pathe";
 import { debounce } from "perfect-debounce";
 import { withBase } from "ufo";
 import { scanHandlers } from "../../scan.ts";
+import { getSourceExtensionPattern } from "../../utils/source-extensions.ts";
 import { getEnvRunner } from "./env.ts";
 
 // https://vite.dev/guide/api-environment-runtimes.html#modulerunner
@@ -112,6 +113,8 @@ export class FetchableDevEnvironment extends DevEnvironment {
 export async function configureViteDevServer(ctx: NitroPluginContext, server: ViteDevServer) {
   const nitro = ctx.nitro!;
   const nitroEnv = server.environments.nitro as FetchableDevEnvironment;
+  const sourceExtensionPattern = getSourceExtensionPattern(nitro.options);
+  const serverEntryRe = new RegExp(String.raw`^server(?:\.node)?\.(?:${sourceExtensionPattern})$`);
 
   // Restart with nitro.config changes
   const nitroConfigFile = nitro.options._c12.configFile;
@@ -160,7 +163,7 @@ export async function configureViteDevServer(ctx: NitroPluginContext, server: Vi
     nitro.options.rootDir,
     { persistent: false },
     (_event, filename) => {
-      if (filename && /^server\.[mc]?[jt]sx?$/.test(filename)) {
+      if (filename && serverEntryRe.test(filename)) {
         reload();
       }
     }

src/build/vite/env.ts

@@ -8,6 +8,7 @@ import { runtimeDependencies, runtimeDir } from "nitro/meta";
 import { resolveModulePath } from "exsolve";
 import { createFetchableDevEnvironment } from "./dev.ts";
 import { isAbsolute } from "pathe";
+import { getSourceExtensions } from "../../utils/source-extensions.ts";
 
 export function createNitroEnvironment(ctx: NitroPluginContext): EnvironmentOptions {
   const isWorkerdRunner = _isWorkerdRunner(ctx);
@@ -89,7 +90,7 @@ export function createServiceEnvironment(
     },
     dev: {
       createEnvironment: (envName, envConfig) => {
-        const entry = tryResolve(serviceConfig.entry);
+        const entry = tryResolve(serviceConfig.entry, ctx.nitro!.options.sourceExtensions);
         (ctx._viteEnvs ??= new Map()).set(envName, entry);
         return createFetchableDevEnvironment(envName, envConfig, getEnvRunner(ctx), entry, {
           preventExternalize: isWorkerdRunner,
@@ -237,13 +238,14 @@ function _isWorkerdRunner(ctx: NitroPluginContext): boolean {
   return runnerName === "miniflare";
 }
 
-function tryResolve(id: string) {
+function tryResolve(id: string, sourceExtensions: string[] = []) {
   if (/^[~#/\0]/.test(id) || isAbsolute(id)) {
     return id;
   }
+  const resolvableSourceExtensions = getSourceExtensions({ sourceExtensions });
   const resolved = resolveModulePath(id, {
     suffixes: ["", "/index"],
-    extensions: ["", ".ts", ".mjs", ".cjs", ".js", ".mts", ".cts"],
+    extensions: ["", ...resolvableSourceExtensions],
     try: true,
   });
   return resolved || id;

src/build/vite/plugin.ts

@@ -29,12 +29,11 @@ import { NitroDevApp } from "../../dev/app.ts";
 import { nitroPreviewPlugin } from "./preview.ts";
 import assetsPlugin from "@hiogawa/vite-plugin-fullstack/assets";
 import type { NitroConfig } from "nitro/types";
+import { getSourceExtensions } from "../../utils/source-extensions.ts";
 
 // https://vite.dev/guide/api-environment-plugins
 // https://vite.dev/guide/api-environment-frameworks.html
 
-const DEFAULT_EXTENSIONS = [".ts", ".js", ".mts", ".mjs", ".tsx", ".jsx"];
-
 const debug = process.env.NITRO_DEBUG
   ? (...args: any[]) => console.log("[nitro]", ...args)
   : () => {};
@@ -145,7 +144,7 @@ function nitroEnv(ctx: NitroPluginContext): VitePlugin {
       const resolvedEntry =
         resolveModulePath(entry, {
           from: [ctx.nitro!.options.rootDir, ...ctx.nitro!.options.scanDirs],
-          extensions: DEFAULT_EXTENSIONS,
+          extensions: getSourceExtensions(ctx.nitro!.options),
           suffixes: ["", "/index"],
           try: true,
         }) || entry;
@@ -398,7 +397,7 @@ async function setupNitroContext(
         from: ["app", "src", ""].flatMap((d) =>
           [ctx.nitro!.options.rootDir, ...ctx.nitro!.options.scanDirs].map((s) => join(s, d) + "/")
         ),
-        extensions: DEFAULT_EXTENSIONS,
+        extensions: getSourceExtensions(ctx.nitro!.options),
         try: true,
       });
       if (ssrEntry) {
@@ -411,7 +410,7 @@ async function setupNitroContext(
         ssrEntry =
           resolveModulePath(ssrEntry, {
             from: [ctx.nitro.options.rootDir, ...ctx.nitro.options.scanDirs],
-            extensions: DEFAULT_EXTENSIONS,
+            extensions: getSourceExtensions(ctx.nitro.options),
             suffixes: ["", "/index"],
             try: true,
           }) || ssrEntry;

src/config/defaults.ts

@@ -12,6 +12,7 @@ export const NitroDefaults: NitroConfig = {
   // Dirs
   serverDir: false,
   scanDirs: [],
+  sourceExtensions: [],
   buildDir: `node_modules/.nitro`,
   output: {
     dir: "{{ rootDir }}/.output",

src/config/resolvers/paths.ts

@@ -6,8 +6,7 @@ import { findWorkspaceDir } from "pkg-types";
 import { NitroDefaults } from "../defaults.ts";
 import { resolveModulePath } from "exsolve";
 import consola from "consola";
-
-const RESOLVE_EXTENSIONS = [".ts", ".js", ".mts", ".mjs", ".tsx", ".jsx"];
+import { getSourceExtensions, normalizeSourceExtensions } from "../../utils/source-extensions.ts";
 
 export async function resolvePathOptions(options: NitroOptions) {
   options.rootDir = resolve(options.rootDir || ".") + "/";
@@ -30,6 +29,7 @@ export async function resolvePathOptions(options: NitroOptions) {
   }
 
   options.alias ??= {};
+  options.sourceExtensions = normalizeSourceExtensions(options.sourceExtensions);
 
   // Resolve possibly template paths
   if (!options.static && !options.entry) {
@@ -93,7 +93,7 @@ export async function resolvePathOptions(options: NitroOptions) {
       const detected = resolveModulePath("./server", {
         try: true,
         from: options.rootDir,
-        extensions: RESOLVE_EXTENSIONS.flatMap((ext) => [ext, `.node${ext}`]),
+        extensions: getSourceExtensions(options).flatMap((ext) => [ext, `.node${ext}`]),
       });
       if (detected) {
         options.serverEntry ??= { handler: "" };
@@ -118,7 +118,7 @@ export async function resolvePathOptions(options: NitroOptions) {
         resolveNitroPath(options.renderer?.handler, options),
         {
           from: [options.rootDir, ...options.scanDirs],
-          extensions: RESOLVE_EXTENSIONS,
+          extensions: getSourceExtensions(options),
         }
       );
     }

src/module.ts

@@ -1,5 +1,6 @@
 import type { Nitro, NitroModule, NitroModuleInput } from "nitro/types";
 import { resolveModuleURL } from "exsolve";
+import { getSourceExtensions } from "./utils/source-extensions.ts";
 
 export async function installModules(nitro: Nitro) {
   const _modules = [...(nitro.options.modules || [])];
@@ -25,7 +26,7 @@ async function _resolveNitroModule(
   if (typeof mod === "string") {
     _url = resolveModuleURL(mod, {
       from: [nitroOptions.rootDir],
-      extensions: [".mjs", ".cjs", ".js", ".mts", ".cts", ".ts"],
+      extensions: getSourceExtensions(nitroOptions),
     });
     mod = (await import(_url).then((m: any) => m.default || m)) as NitroModule;
   }

src/presets/cloudflare/entry-exports.ts

@@ -1,8 +1,7 @@
 import type { Nitro } from "nitro/types";
 import { resolveModulePath } from "exsolve";
 import { prettyPath } from "../../utils/fs.ts";
-
-const RESOLVE_EXTENSIONS = [".ts", ".js", ".mts", ".mjs"];
+import { getSourceExtensions } from "../../utils/source-extensions.ts";
 
 export async function setupEntryExports(nitro: Nitro) {
   const exportsEntry = resolveExportsEntry(nitro);
@@ -21,7 +20,7 @@ export async function setupEntryExports(nitro: Nitro) {
 function resolveExportsEntry(nitro: Nitro) {
   const entry = resolveModulePath(nitro.options.cloudflare?.exports || "./exports.cloudflare.ts", {
     from: nitro.options.rootDir,
-    extensions: RESOLVE_EXTENSIONS,
+    extensions: getSourceExtensions(nitro.options),
     try: true,
   });
 

src/scan.ts

@@ -2,8 +2,7 @@ import { glob } from "tinyglobby";
 import type { Nitro } from "nitro/types";
 import { join, relative } from "pathe";
 import { withBase, withLeadingSlash, withoutTrailingSlash } from "ufo";
-
-export const GLOB_SCAN_PATTERN = "**/*.{js,mjs,cjs,ts,mts,cts,tsx,jsx}";
+import { getScanPattern, stripSourceExtension } from "./utils/source-extensions.ts";
 type FileInfo = { path: string; fullPath: string };
 
 const suffixRegex =
@@ -85,8 +84,7 @@ export async function scanMiddleware(nitro: Nitro) {
 export async function scanServerRoutes(nitro: Nitro, dir: string, prefix = "/") {
   const files = await scanFiles(nitro, dir);
   return files.map((file) => {
-    let route = file.path
-      .replace(/\.[A-Za-z]+$/, "")
+    let route = stripSourceExtension(file.path, nitro.options)
       .replace(/\(([^(/\\]+)\)[/\\]/g, "")
       .replace(/\[\.{3}]/g, "**")
       .replace(/\[\.{3}([^\]]+)]/g, (_, p) => "**:" + p.replace(/[^\w-]/g, "_"))
@@ -123,9 +121,8 @@ export async function scanPlugins(nitro: Nitro) {
 export async function scanTasks(nitro: Nitro) {
   const files = await scanFiles(nitro, "tasks");
   return files.map((f) => {
-    const name = f.path
+    const name = stripSourceExtension(f.path, nitro.options)
       .replace(/\/index$/, "")
-      .replace(/\.[A-Za-z]+$/, "")
       .replace(/\//g, ":");
     return { name, handler: f.fullPath };
   });
@@ -144,7 +141,7 @@ async function scanFiles(nitro: Nitro, name: string): Promise<FileInfo[]> {
 }
 
 async function scanDir(nitro: Nitro, dir: string, name: string): Promise<FileInfo[]> {
-  const fileNames = await glob(join(name, GLOB_SCAN_PATTERN), {
+  const fileNames = await glob(join(name, getScanPattern(nitro.options)), {
     cwd: dir,
     dot: true,
     ignore: nitro.options.ignore,

src/types/config.ts

@@ -162,6 +162,27 @@ export interface NitroOptions extends PresetOptions {
    */
   scanDirs: string[];
 
+  /**
+   * Additional script-like source file extensions Nitro should treat like
+   * built-in JS/TS server files.
+   *
+   * These extensions are appended to Nitro's built-in source extensions and
+   * are used for file scanning, entry resolution, generated route types, and
+   * development reload detection.
+   *
+   * When used for Nitro `modules`, custom extensions must also be supported
+   * by the current JS runtime. For example:
+   * `NODE_OPTIONS="--import @danielx/civet/register" pnpm dev`
+   *
+   * @example
+   * ```ts
+   * sourceExtensions: [".civet", ".res"]
+   * ```
+   *
+   * @see https://nitro.build/config#sourceextensions
+   */
+  sourceExtensions: string[];
+
   /**
    * Directory name to scan for API route handlers.
    *