feat: allow passing down resolved config to vite's createServer (#19894)

Author: sheremet-va

packages/vite/src/node/config.ts

@@ -106,6 +106,7 @@ import { getAdditionalAllowedHosts } from './server/middlewares/hostCheck'
 
 const debug = createDebugger('vite:config', { depth: 10 })
 const promisifiedRealpath = promisify(fs.realpath)
+const SYMBOL_RESOLVED_CONFIG = Symbol('vite:resolved-config')
 
 export interface ConfigEnv {
   /**
@@ -641,6 +642,8 @@ export interface ResolvedConfig
       safeModulePaths: Set<string>
       /** @internal */
       additionalAllowedHosts: string[]
+      /** @internal */
+      [SYMBOL_RESOLVED_CONFIG]: true
     } & PluginHookUtils
   > {}
 
@@ -1044,6 +1047,15 @@ function resolveDepOptimizationOptions(
   )
 }
 
+export function isResolvedConfig(
+  inlineConfig: InlineConfig | ResolvedConfig,
+): inlineConfig is ResolvedConfig {
+  return (
+    SYMBOL_RESOLVED_CONFIG in inlineConfig &&
+    inlineConfig[SYMBOL_RESOLVED_CONFIG]
+  )
+}
+
 export async function resolveConfig(
   inlineConfig: InlineConfig,
   command: 'build' | 'serve',
@@ -1555,6 +1567,7 @@ export async function resolveConfig(
     ),
     safeModulePaths: new Set<string>(),
     additionalAllowedHosts: getAdditionalAllowedHosts(server, preview),
+    [SYMBOL_RESOLVED_CONFIG]: true,
   }
   resolved = {
     ...config,

packages/vite/src/node/server/index.ts

@@ -23,7 +23,7 @@ import {
   setClientErrorHandler,
 } from '../http'
 import type { InlineConfig, ResolvedConfig } from '../config'
-import { resolveConfig } from '../config'
+import { isResolvedConfig, resolveConfig } from '../config'
 import {
   diffDnsOrderChange,
   getServerUrlByHost,
@@ -101,6 +101,8 @@ import type { DevEnvironment } from './environment'
 import { hostCheckMiddleware } from './middlewares/hostCheck'
 import { rejectInvalidRequestMiddleware } from './middlewares/rejectInvalidRequest'
 
+const usedConfigs = new WeakSet<ResolvedConfig>()
+
 export interface ServerOptions extends CommonServerOptions {
   /**
    * Configure HMR-specific options (port, host, path & protocol)
@@ -420,19 +422,33 @@ export interface ResolvedServerUrls {
 }
 
 export function createServer(
-  inlineConfig: InlineConfig = {},
+  inlineConfig: InlineConfig | ResolvedConfig = {},
 ): Promise<ViteDevServer> {
   return _createServer(inlineConfig, { listen: true })
 }
 
 export async function _createServer(
-  inlineConfig: InlineConfig = {},
+  inlineConfig: InlineConfig | ResolvedConfig = {},
   options: {
     listen: boolean
     previousEnvironments?: Record<string, DevEnvironment>
   },
 ): Promise<ViteDevServer> {
-  const config = await resolveConfig(inlineConfig, 'serve')
+  const config = isResolvedConfig(inlineConfig)
+    ? inlineConfig
+    : await resolveConfig(inlineConfig, 'serve')
+
+  if (usedConfigs.has(config)) {
+    throw new Error(`There is already a server associated with the config.`)
+  }
+
+  if (config.command !== 'serve') {
+    throw new Error(
+      `Config was resolved for a "build", expected a "serve" command.`,
+    )
+  }
+
+  usedConfigs.add(config)
 
   const initPublicFilesPromise = initPublicFiles(config)