TanStack · s3847243 · Nov 5, 2025 · Nov 6, 2025
diff --git a/packages/start-server-core/src/createStartHandler.ts b/packages/start-server-core/src/createStartHandler.ts
@@ -380,12 +380,32 @@ async function handleServerRoutes({
               createHandlers: (d: any) => d,
             })
           : server.handlers
+      const normalizedHandlers: Record<string, any> = {}
+      for (const [k, v] of Object.entries(handlers)) {
+        normalizedHandlers[k.toUpperCase()] = v
+      }
 
-      const requestMethod = request.method.toUpperCase() as RouteMethod
-
+      let requestMethod = request.method.toUpperCase() as RouteMethod
+      if (requestMethod === 'HEAD' && normalizedHandlers["GET"]) {
+        requestMethod = 'GET' as RouteMethod
+      }
+      const hasAny = !!normalizedHandlers["ANY"]
       // Attempt to find the method in the handlers
-      const handler = handlers[requestMethod] ?? handlers['ANY']
+      const handler = normalizedHandlers[requestMethod] ?? normalizedHandlers["ANY"]
+      if (!handler && !hasAny) {
 
+        if (request.method.toUpperCase() === 'HEAD') {
+          return new Response(null, {
+            status: 404,
+            headers: { 'Content-Type': 'application/json' }, 
+          })
+        }
+
+        return new Response(JSON.stringify({ error: 'Not Found' }), {
+          status: 404,
+          headers: { 'Content-Type': 'application/json' },
+        })
+      }
       // If a method is found, execute the handler
       if (handler) {
         const mayDefer = !!foundRoute.options.component

diff --git a/packages/start-server-core/tests/createStartHandler.test.ts b/packages/start-server-core/tests/createStartHandler.test.ts
@@ -0,0 +1,81 @@
+import { describe, it, expect, beforeEach } from 'vitest'
+import { createStartHandler } from '../src'
+import { currentHandlers } from './mocks/router-entry'
+
+
+const spaFallback = async () =>
+  new Response('<!doctype html><div>spa</div>', {
+    status: 200,
+    headers: { 'Content-Type': 'text/html' },
+  })
+
+function makeApp() {
+  return createStartHandler(async () => await spaFallback())
+}
+beforeEach(() => {
+  Object.keys(currentHandlers).forEach(key => delete currentHandlers[key])
+})
+
+describe('createStartHandler — server route HTTP method handling', function () {
+  it('should return 404 JSON for GET when only POST is defined (no SPA fallback)', async function () {
+    currentHandlers.POST = () => new Response('ok', { status: 200 })
+    const app = makeApp()
+
+    const res = await app(
+      new Request('http://localhost/api/test-no-get', { method: 'GET' }),
+    )
+
+    expect(res.status).toBe(404)
+    expect(res.headers.get('content-type')).toMatch(/application\/json/i)
+    const txt = await res.text()
+    expect(txt).toContain('Not Found')
+    expect(txt.toLowerCase().startsWith('<!doctype html>')).toBe(false)
+  })
+
+  it('should return 200 for POST and execute the route handler', async function () {
+    currentHandlers.POST = () => new Response('ok', { status: 200 })
+    const app = makeApp()
+
+    const res = await app(
+      new Request('http://localhost/api/test-no-get', { method: 'POST' }),
+    )
+
+    expect(res.status).toBe(200)
+    expect(await res.text()).toBe('ok')
+  })
+
+  it('should return 404 for HEAD when GET is not defined', async function () {
+    currentHandlers.POST = () => new Response('ok', { status: 200 })
+    const app = makeApp()
+
+    const res = await app(
+      new Request('http://localhost/api/test-no-get', { method: 'HEAD' }),
+    )
+
+    expect(res.status).toBe(404)
+  })
+
+  it('should use GET handler when HEAD is requested and GET exists', async function () {
+    currentHandlers.GET = () => new Response('hello', { status: 200 })
+    const app = makeApp()
+
+    const res = await app(
+      new Request('http://localhost/api/has-get', { method: 'HEAD' }),
+    )
+
+    expect(res.status).toBe(200)
+  })
+
+  it('should execute ANY handler for unsupported methods (e.g., PUT)', async function () {
+    currentHandlers.ANY = () => new Response('ok-any', { status: 200 })
+    const app = makeApp()
+
+    const res = await app(
+      new Request('http://localhost/api/any', { method: 'PUT' }),
+    )
+
+    expect(res.status).toBe(200)
+    expect(await res.text()).toBe('ok-any')
+  })
+})
+
diff --git a/packages/start-server-core/tests/mocks/injected-head-scripts.ts b/packages/start-server-core/tests/mocks/injected-head-scripts.ts
@@ -0,0 +1 @@
+export const injectedHeadScripts = ''
diff --git a/packages/start-server-core/tests/mocks/router-entry.ts b/packages/start-server-core/tests/mocks/router-entry.ts
@@ -0,0 +1,30 @@
+import { AnyRouter } from '@tanstack/router-core'
+
+export let currentHandlers: Record<string, any> = {}
+
+function makeFakeRouter(): AnyRouter {
+  return {
+    rewrite: undefined as any,
+    getMatchedRoutes: (_pathname: string) => ({
+      matchedRoutes: [{ options: { server: { middleware: [] } } }],
+      foundRoute: {
+        options: {
+          server: { handlers: currentHandlers },
+          component: undefined, 
+        },
+      },
+      routeParams: {},
+    }),
+
+    update: () => {},
+    load: async () => {},
+    state: { redirect: null } as any,
+    serverSsr: { dehydrate: async () => {} } as any,
+    options: {} as any,
+    resolveRedirect: (r: any) => r,
+  } as unknown as AnyRouter
+}
+
+export async function getRouter() {
+  return makeFakeRouter()
+}
diff --git a/packages/start-server-core/tests/mocks/start-entry.ts b/packages/start-server-core/tests/mocks/start-entry.ts
@@ -0,0 +1,7 @@
+export const startInstance = {
+  getOptions: async () => ({
+    requestMiddleware: undefined,
+    defaultSsr: undefined,
+    serializationAdapters: [],
+  }),
+}
diff --git a/packages/start-server-core/tests/mocks/start-manifest.ts b/packages/start-server-core/tests/mocks/start-manifest.ts
@@ -0,0 +1,10 @@
+export const tsrStartManifest = () => ({
+  routes: {
+    __root__: {
+      id: '__root__',
+    },
+  },
+  routeTree: {
+    id: '__root__',
+  },
+})
diff --git a/packages/start-server-core/vite.config.ts b/packages/start-server-core/vite.config.ts
@@ -4,14 +4,23 @@ import packageJson from './package.json'
 // this needs to be imported from the actual file instead of from 'index.tsx'
 // so we don't trigger the import of a `?script-string` import before the minifyScriptPlugin is setup
 import { VIRTUAL_MODULES } from './src/virtual-modules'
-
+import path from 'path'
 const config = defineConfig({
   test: {
     include: ['**/*.{test-d,test,spec}.?(c|m)[jt]s?(x)'],
     name: packageJson.name,
     watch: false,
     environment: 'jsdom',
   },
+  resolve: {
+    alias: {
+      '#tanstack-router-entry': path.resolve(__dirname, './tests/mocks/router-entry.ts'),
+      '#tanstack-start-entry': path.resolve(__dirname, './tests/mocks/start-entry.ts'),
+      'tanstack-start-manifest:v': path.resolve(__dirname, './tests/mocks/start-manifest.ts'),
+      'tanstack-start-injected-head-scripts:v': path.resolve(__dirname, './tests/mocks/injected-head-scripts.ts'),
+
+    }
+  }
 })
 
 export default mergeConfig(