feat: pass config env to plugin config hook

docs/guide/api-plugin.md

@@ -111,10 +111,10 @@ Vite plugins can also provide hooks that serve Vite-specific purposes. These hoo
 
 ### `config`
 
-- **Type:** `(config: UserConfig) => UserConfig | null | void`
+- **Type:** `(config: UserConfig, env: { mode: string, command: string }) => UserConfig | null | void`
 - **Kind:** `sync`, `sequential`
 
-  Modify Vite config before it's resolved. The hook receives the raw user config (CLI options merged with config file). It can return a partial config object that will be deeply merged into existing config, or directly mutate the config (if the default merging cannot achieve the desired result).
+  Modify Vite config before it's resolved. The hook receives the raw user config (CLI options merged with config file) and the current config env which exposes the `mode` and `command` being used. It can return a partial config object that will be deeply merged into existing config, or directly mutate the config (if the default merging cannot achieve the desired result).
 
   **Example**
 
@@ -132,8 +132,10 @@ Vite plugins can also provide hooks that serve Vite-specific purposes. These hoo
   // mutate the config directly (use only when merging doesn't work)
   const mutateConfigPlugin = () => ({
     name: 'mutate-config',
-    config(config) {
-      config.root = __dirname
+    config(config, { command }) {
+      if (command === 'build') {
+        config.root = __dirname
+      }
     }
   })
   ```
@@ -410,8 +412,8 @@ Vite normalizes paths while resolving ids to use POSIX separators ( / ) while pr
 So, for Vite plugins, when comparing paths against resolved ids it is important to first normalize the paths to use POSIX separators. An equivalent `normalizePath` utility function is exported from the `vite` module.
 
 ```js
-import { normalizePath } from 'vite';
+import { normalizePath } from 'vite'
 
-normalizePath('foo\\bar'); // 'foo/bar'
-normalizePath('foo/bar'); // 'foo/bar'
-```
+normalizePath('foo\\bar') // 'foo/bar'
+normalizePath('foo/bar') // 'foo/bar'
+```

packages/vite/src/node/config.ts

@@ -206,13 +206,15 @@ export async function resolveConfig(
     process.env.NODE_ENV = 'production'
   }
 
+  const configEnv = {
+    mode,
+    command
+  }
+
   let { configFile } = config
   if (configFile !== false) {
     const loadResult = await loadConfigFromFile(
-      {
-        mode,
-        command
-      },
+      configEnv,
       configFile,
       config.root,
       config.logLevel
@@ -237,7 +239,7 @@ export async function resolveConfig(
   const userPlugins = [...prePlugins, ...normalPlugins, ...postPlugins]
   userPlugins.forEach((p) => {
     if (p.config) {
-      const res = p.config(config)
+      const res = p.config(config, configEnv)
       if (res) {
         config = mergeConfig(config, res)
       }

packages/vite/src/node/plugin.ts

@@ -11,7 +11,7 @@ import {
 import { ServerHook } from './server'
 import { IndexHtmlTransform } from './plugins/html'
 import { ModuleNode } from './server/moduleGraph'
-import { ResolvedConfig } from './'
+import { ConfigEnv, ResolvedConfig } from './'
 import { HmrContext } from './server/hmr'
 
 /**
@@ -61,7 +61,7 @@ export interface Plugin extends RollupPlugin {
    * Note: User plugins are resolved before running this hook so injecting other
    * plugins inside  the `config` hook will have no effect.
    */
-  config?: (config: UserConfig) => UserConfig | null | void
+  config?: (config: UserConfig, env: ConfigEnv) => UserConfig | null | void
   /**
    * Use this hook to read and store the final resolved vite config.
    */