feat(kit,schema): add addServerTemplate utility (#29320)

packages/kit/src/template.ts

@@ -1,7 +1,7 @@
 import { existsSync, promises as fsp } from 'node:fs'
 import { basename, isAbsolute, join, parse, relative, resolve } from 'pathe'
 import hash from 'hash-sum'
-import type { Nuxt, NuxtTemplate, NuxtTypeTemplate, ResolvedNuxtTemplate, TSReference } from '@nuxt/schema'
+import type { Nuxt, NuxtServerTemplate, NuxtTemplate, NuxtTypeTemplate, ResolvedNuxtTemplate, TSReference } from '@nuxt/schema'
 import { withTrailingSlash } from 'ufo'
 import { defu } from 'defu'
 import type { TSConfig } from 'pkg-types'
@@ -32,6 +32,18 @@ export function addTemplate<T> (_template: NuxtTemplate<T> | string) {
   return template
 }
 
+/**
+ * Adds a virtual file that can be used within the Nuxt Nitro server build.
+ */
+export function addServerTemplate (template: NuxtServerTemplate) {
+  const nuxt = useNuxt()
+
+  nuxt.options.nitro.virtual ||= {}
+  nuxt.options.nitro.virtual[template.filename] = template.getContents
+
+  return template
+}
+
 /**
  * Renders given types using lodash template during build into the project buildDir
  * and register them as types.

packages/schema/src/index.ts

@@ -6,7 +6,7 @@ export type { GenerateAppOptions, HookResult, ImportPresetWithDeprecation, NuxtA
 export type { ImportsOptions } from './types/imports'
 export type { AppHeadMetaObject, MetaObject, MetaObjectRaw, HeadAugmentations } from './types/head'
 export type { ModuleDefinition, ModuleMeta, ModuleOptions, ModuleSetupInstallResult, ModuleSetupReturn, NuxtModule, ResolvedModuleOptions } from './types/module'
-export type { Nuxt, NuxtApp, NuxtPlugin, NuxtPluginTemplate, NuxtTemplate, NuxtTypeTemplate, ResolvedNuxtTemplate } from './types/nuxt'
+export type { Nuxt, NuxtApp, NuxtPlugin, NuxtPluginTemplate, NuxtTemplate, NuxtTypeTemplate, NuxtServerTemplate, ResolvedNuxtTemplate } from './types/nuxt'
 export type { RouterConfig, RouterConfigSerializable, RouterOptions } from './types/router'
 
 // Schema

packages/schema/src/types/nuxt.ts

@@ -42,6 +42,12 @@ export interface NuxtTemplate<Options = TemplateDefaultOptions> {
   write?: boolean
 }
 
+export interface NuxtServerTemplate {
+  /** The target filename once the template is copied into the Nuxt buildDir */
+  filename: string
+  getContents: () => string | Promise<string>
+}
+
 export interface ResolvedNuxtTemplate<Options = TemplateDefaultOptions> extends NuxtTemplate<Options> {
   filename: string
   dst: string