From d39ca90599a51e07db36fe9d91301ebe518ce00b Mon Sep 17 00:00:00 2001
From: Guillaume Chau <guillaume.b.chau@gmail.com>
Date: Thu, 10 Mar 2022 00:57:14 +0100
Subject: [PATCH] feat(config): vite as function to mutate config

---
 packages/histoire-controls/vite.config.ts | 10 +++-------
 packages/histoire/src/node/config.ts      |  4 ++--
 packages/histoire/src/node/plugin.ts      |  4 ++--
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/packages/histoire-controls/vite.config.ts b/packages/histoire-controls/vite.config.ts
index 948bd815..6b1356f0 100644
--- a/packages/histoire-controls/vite.config.ts
+++ b/packages/histoire-controls/vite.config.ts
@@ -26,13 +26,9 @@ export default defineConfig({
 
   histoire: {
     setupFile: '/src/histoire-setup.ts',
-    vite: {
-      build: {
-        lib: false,
-        rollupOptions: {
-          external: [],
-        },
-      },
+    vite: (config) => {
+      config.build.lib = false
+      config.build.rollupOptions.external = []
     },
   },
 
diff --git a/packages/histoire/src/node/config.ts b/packages/histoire/src/node/config.ts
index 39b18c79..f7472e01 100644
--- a/packages/histoire/src/node/config.ts
+++ b/packages/histoire/src/node/config.ts
@@ -1,7 +1,7 @@
 import path from 'pathe'
 import fs from 'fs'
 import defu from 'defu'
-import { createServer, resolveConfig as resolveViteConfig, UserConfig as ViteConfig } from 'vite'
+import { createServer, resolveConfig as resolveViteConfig, UserConfig as ViteConfig, ConfigEnv as ViteConfigEnv } from 'vite'
 import { ViteNodeServer } from 'vite-node/server'
 import { ViteNodeRunner } from 'vite-node/client'
 import pc from 'picocolors'
@@ -123,7 +123,7 @@ export interface HistoireConfig {
   /**
    * Vite config override
    */
-  vite?: ViteConfig
+  vite?: ViteConfig | ((config: ViteConfig, env: ViteConfigEnv) => void | ViteConfig | Promise<void | ViteConfig>)
 }
 
 export function getDefaultConfig (): HistoireConfig {
diff --git a/packages/histoire/src/node/plugin.ts b/packages/histoire/src/node/plugin.ts
index 2b13dd92..ef448ec7 100644
--- a/packages/histoire/src/node/plugin.ts
+++ b/packages/histoire/src/node/plugin.ts
@@ -30,8 +30,8 @@ export async function createVitePlugins (ctx: Context): Promise<VitePlugin[]> {
   if (ctx.config.vite) {
     plugins.push({
       name: 'histoire-vite-config-override',
-      config () {
-        return ctx.config.vite
+      config (config, env) {
+        return typeof ctx.config.vite === 'function' ? ctx.config.vite(config, env) : ctx.config.vite
       },
     })
   }