fix: try to resolve server entry also from index file

Author: lazerg

src/config/resolvers/paths.ts

@@ -96,6 +96,7 @@ export async function resolvePathOptions(options: NitroOptions) {
           options.serverDir && options.serverDir !== options.rootDir
             ? [options.serverDir, options.rootDir]
             : options.rootDir,
+        suffixes: ["", "/index"],
         extensions: RESOLVE_EXTENSIONS.flatMap((ext) => [ext, `.node${ext}`]),
       });
       if (detected) {

test/unit/server-entry.test.ts

@@ -0,0 +1,51 @@
+import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { dirname, join } from "pathe";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("nitro/meta", () => ({
+  version: "0.0.0-test",
+  runtimeDir: "/tmp",
+  presetsDir: "/tmp",
+  pkgDir: "/tmp",
+  runtimeDependencies: [],
+}));
+
+const tempDirs: string[] = [];
+
+async function detectServerEntry(entry: string) {
+  const rootDir = await mkdtemp(join(tmpdir(), "nitro-server-entry-"));
+  tempDirs.push(rootDir);
+
+  const file = join(rootDir, entry);
+  await mkdir(dirname(file), { recursive: true });
+  await writeFile(file, `export default { fetch: () => new Response("ok") };\n`);
+
+  const { loadOptions } = await import("../../src/config/loader.ts");
+  const { serverEntry } = await loadOptions({
+    rootDir,
+    preset: "node-server",
+    compatibilityDate: "latest",
+  });
+  return serverEntry as { handler: string } | false;
+}
+
+afterEach(async () => {
+  for (const dir of tempDirs.splice(0, tempDirs.length)) {
+    await rm(dir, { recursive: true, force: true });
+  }
+});
+
+describe("server entry detection", () => {
+  it("detects `server.ts` in the root directory", async () => {
+    const serverEntry = await detectServerEntry("server.ts");
+    expect(serverEntry).toBeTruthy();
+    expect((serverEntry as { handler: string }).handler).toContain("/server.ts");
+  });
+
+  it("detects `server/index.ts`", async () => {
+    const serverEntry = await detectServerEntry("server/index.ts");
+    expect(serverEntry).toBeTruthy();
+    expect((serverEntry as { handler: string }).handler).toContain("/server/index.ts");
+  });
+});