major refactor: move main logic into resolveUserConfig()

src/client/app/data.ts

@@ -19,7 +19,7 @@ import {
   type SiteData
 } from '../shared'
 import type { Route } from './router'
-import { dirname, stackView } from './utils'
+import { stackView } from './utils'
 
 export const dataSymbol: InjectionKey<VitePressData> = Symbol()
 
@@ -70,49 +70,45 @@ if (import.meta.hot) {
   })
 }
 
-// hierarchical config pre-loading
-const extraConfig: Record<string, SiteData> = Object.fromEntries(
-  Object.entries(
-    import.meta.glob('/**/config.([cm]?js|ts|json)', {
-      eager: true
+function debugConfigLayers(path: string, layers: SiteData[]): SiteData[] {
+  // debug info
+  if (inBrowser && import.meta.env.DEV) {
+    const summaryTitle = `Config Layers for ${path}:`
+    const summary = layers.map((c, i, arr) => {
+      const n = i + 1
+      if (n === arr.length) return `${n}. .vitepress/config (root)`
+      return `${n}. ${(c as any)?.VP_SOURCE ?? '(Unknown Source)'}`
     })
-  ).map(([path, module]) => [
-    dirname(path),
-    { __module__: path, ...((module as any)?.default ?? module) }
-  ])
+    console.debug(
+      [summaryTitle, ''.padEnd(summaryTitle.length, '='), ...summary].join('\n')
     )
+  }
+  return layers
+}
 
-function getExtraConfigs(path: string): SiteData[] {
+function getConfigLayers(root: SiteData, path: string): SiteData[] {
   if (!path.startsWith('/')) path = `/${path}`
+  const additionalConfig = root.additionalConfig
+  if (additionalConfig === undefined) return [root]
+  else if (typeof additionalConfig === 'function')
+    return [...(additionalConfig(path) as SiteData[]), root]
   const configs: SiteData[] = []
   const segments = path.split('/').slice(1, -1)
   while (segments.length) {
     const key = `/${segments.join('/')}/`
-    if (key in extraConfig) configs.push(extraConfig[key])
+    if (key in additionalConfig) configs.push(additionalConfig[key] as SiteData)
     segments.pop()
   }
-  // debug info
-  if (inBrowser) {
-    const summaryTitle = `Config Layers for ${path}:`
-    const summary = configs.map(
-      (c, i) => `  ${i + 1}. ${(c as any).__module__}`
-    )
-    summary.push(`  ${summary.length + 1}. .vitepress/config (root)`)
-    console.debug(
-      [summaryTitle, ''.padEnd(summaryTitle.length, '='), ...summary].join('\n')
-    )
-  }
-  return configs
+  return [...configs, root]
 }
 
 // per-app data
 export function initData(route: Route): VitePressData {
   const site = computed(() => {
-    const data = resolveSiteDataByRoute(
-      siteDataRef.value,
-      route.data.relativePath
-    )
-    return stackView(...getExtraConfigs(route.data.relativePath), data)
+    ;(window as any).siteData = siteDataRef.value
+    const path = route.data.relativePath
+    const data = resolveSiteDataByRoute(siteDataRef.value, path)
+    return stackView(...debugConfigLayers(path, getConfigLayers(data, path)))
   })
 
   const appearance = site.value.appearance // fine with reactivity being lost here, config change triggers a restart

src/client/app/utils.ts

@@ -141,12 +141,6 @@ function tryOffsetSelector(selector: string, padding: number): number {
   return bot + padding
 }
 
-export function dirname(path: string) {
-  const segments = path.split('/')
-  segments[segments.length - 1] = ''
-  return segments.join('/')
-}
-
 const unpackStackView = Symbol('unpackStackView')
 
 function isStackable(obj: any) {

src/node/config.ts

@@ -14,6 +14,11 @@ import type { DefaultTheme } from './defaultTheme'
 import { resolvePages } from './plugins/dynamicRoutesPlugin'
 import { APPEARANCE_KEY, slash, type HeadConfig, type SiteData } from './shared'
 import type { RawConfigExports, SiteConfig, UserConfig } from './siteConfig'
+import type {
+  AdditionalConfigDict,
+  AdditionalConfigEntry
+} from '../../types/shared'
+import { glob } from 'tinyglobby'
 
 export { resolvePages } from './plugins/dynamicRoutesPlugin'
 export * from './siteConfig'
@@ -140,7 +145,65 @@ export async function resolveConfig(
   return config
 }
 
-const supportedConfigExtensions = ['js', 'ts', 'mjs', 'mts']
+export const supportedConfigExtensions = ['js', 'ts', 'mjs', 'mts']
+
+export function isAdditionalConfigFile(path: string) {
+  const filename_to_check = path.split('/').pop() ?? ''
+  for (const filename of supportedConfigExtensions.map((e) => `config.${e}`)) {
+    if (filename_to_check === filename) {
+      return true
+    }
+  }
+  return false
+}
+
+/**
+ * Make sure the path ends with a slash.
+ * If path points to a file, remove the filename component.
+ * @param path
+ * @returns
+ */
+function dirname(path: string) {
+  const segments = path.split('/')
+  segments[segments.length - 1] = ''
+  return segments.join('/')
+}
+
+async function gatherAdditionalConfig(
+  root: string,
+  command: 'serve' | 'build',
+  mode: string
+): Promise<[AdditionalConfigDict, string[][]]> {
+  const pattern = `**/config.{${supportedConfigExtensions.join(',')}}`
+  const candidates = await glob(pattern, {
+    cwd: root,
+    dot: false, // conveniently ignores .vitepress/*
+    ignore: ['**/node_modules/**', '**/.git/**']
+  })
+  const deps: string[][] = []
+  const exports = await Promise.all(
+    candidates.map(async (file) => {
+      const id = '/' + dirname(slash(file))
+      const configExports = await loadConfigFromFile(
+        { command, mode },
+        normalizePath(path.resolve(root, file)),
+        root
+      ).catch(console.error) // Skip additionalConfig file if it fails to load
+      if (!configExports) {
+        debug(`Failed to load additional config from ${file}`)
+        return [id, undefined]
+      }
+      deps.push(
+        configExports.dependencies.map((file) =>
+          normalizePath(path.resolve(file))
+        )
+      )
+      if (mode === 'development') (configExports.config as any).VP_SOURCE = file
+      return [id, configExports.config as AdditionalConfigEntry]
+    })
+  )
+  return [Object.fromEntries(exports.filter(([id, config]) => config)), deps]
+}
 
 export async function resolveUserConfig(
   root: string,
@@ -170,6 +233,16 @@ export async function resolveUserConfig(
       configDeps = configExports.dependencies.map((file) =>
         normalizePath(path.resolve(file))
       )
+      // Auto-generate additional config if user leaves it unspecified
+      if (userConfig.additionalConfig === undefined) {
+        const [additionalConfig, additionalDeps] = await gatherAdditionalConfig(
+          root,
+          command,
+          mode
+        )
+        userConfig.additionalConfig = additionalConfig
+        configDeps = configDeps.concat(...additionalDeps)
+      }
     }
     debug(`loaded config at ${c.yellow(configPath)}`)
   }
@@ -241,7 +314,8 @@ export async function resolveSiteData(
     locales: userConfig.locales || {},
     scrollOffset: userConfig.scrollOffset ?? 134,
     cleanUrls: !!userConfig.cleanUrls,
-    contentProps: userConfig.contentProps
+    contentProps: userConfig.contentProps,
+    additionalConfig: userConfig.additionalConfig
   }
 }
 

src/node/plugin.ts

@@ -15,7 +15,12 @@ import {
   SITE_DATA_REQUEST_PATH,
   resolveAliases
 } from './alias'
-import { resolvePages, resolveUserConfig, type SiteConfig } from './config'
+import {
+  resolvePages,
+  resolveUserConfig,
+  isAdditionalConfigFile,
+  type SiteConfig
+} from './config'
 import { disposeMdItInstance } from './markdown/markdown'
 import {
   clearCache,
@@ -383,7 +388,11 @@ export async function createVitePressPlugin(
     async hotUpdate({ file }) {
       if (this.environment.name !== 'client') return
 
-      if (file === configPath || configDeps.includes(file)) {
+      if (
+        file === configPath ||
+        configDeps.includes(file) ||
+        isAdditionalConfigFile(file)
+      ) {
         siteConfig.logger.info(
           c.green(
             `${path.relative(process.cwd(), file)} changed, restarting server...\n`

src/node/siteConfig.ts

@@ -14,6 +14,7 @@ import type {
   SSGContext,
   SiteData
 } from './shared'
+import type { AdditionalConfig } from '../../types/shared'
 
 export type RawConfigExports<ThemeConfig = any> =
   | Awaitable<UserConfig<ThemeConfig>>
@@ -187,6 +188,13 @@ export interface UserConfig<ThemeConfig = any>
     pageData: PageData,
     ctx: TransformPageContext
   ) => Awaitable<Partial<PageData> | { [key: string]: any } | void>
+
+  /**
+   * @experimental
+   * Multi-layer configuration overloading.
+   * Auto-resolves to docs/.../config.(ts|js|json) when unspecified.
+   */
+  additionalConfig?: AdditionalConfig
 }
 
 export interface SiteConfig<ThemeConfig = any>
@@ -209,6 +217,7 @@ export interface SiteConfig<ThemeConfig = any>
     | 'transformHtml'
     | 'transformPageData'
     | 'sitemap'
+    | 'additionalConfig'
   > {
   root: string
   srcDir: string

types/shared.d.ts

@@ -134,6 +134,7 @@ export interface SiteData<ThemeConfig = any> {
   router: {
     prefetchLinks: boolean
   }
+  additionalConfig?: AdditionalConfig<ThemeConfig>
 }
 
 export type HeadConfig =
@@ -161,6 +162,27 @@ export interface LocaleSpecificConfig<ThemeConfig = any> {
   themeConfig?: ThemeConfig
 }
 
+export interface AdditionalConfigEntry<ThemeConfig = any>
+  extends LocaleSpecificConfig<ThemeConfig> {
+  /**
+   * Source of current config entry, only available in development mode
+   */
+  src?: string
+}
+
+export type AdditionalConfigDict<ThemeConfig = any> = Record<
+  string,
+  AdditionalConfigEntry<ThemeConfig>
+>
+
+export type AdditionalConfigLoader<ThemeConfig = any> = (
+  path: string
+) => AdditionalConfigEntry<ThemeConfig>[]
+
+export type AdditionalConfig<ThemeConfig = any> =
+  | AdditionalConfigDict<ThemeConfig>
+  | AdditionalConfigLoader<ThemeConfig>
+
 export type LocaleConfig<ThemeConfig = any> = Record<
   string,
   LocaleSpecificConfig<ThemeConfig> & { label: string; link?: string }