test: test for define

packages/playground/define/__tests__/define.spec.ts

@@ -0,0 +1,10 @@
+test('string', async () => {
+  const defines = require('../vite.config.js').define
+
+  expect(await page.textContent('.string')).toBe(String(defines.__STRING__))
+  expect(await page.textContent('.number')).toBe(String(defines.__NUMBER__))
+  expect(await page.textContent('.boolean')).toBe(String(defines.__BOOLEAN__))
+  expect(await page.textContent('.object')).toBe(
+    JSON.stringify(defines.__OBJ__, null, 2)
+  )
+})

packages/playground/define/index.html

@@ -0,0 +1,17 @@
+<h1>Define</h1>
+
+<p>String <code class="string"></code></p>
+<p>Number <code class="number"></code></p>
+<p>Boolean <code class="boolean"></code></p>
+<p>Object <pre class="object"></pre></p>
+
+<script type="module">
+text('.string', __STRING__)
+text('.number', __NUMBER__)
+text('.boolean', __BOOLEAN__)
+text('.object', JSON.stringify(__OBJ__, null, 2))
+
+function text(el, text) {
+  document.querySelector(el).textContent = text
+}
+</script>

packages/playground/define/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "test-define",
+  "private": true,
+  "version": "0.0.0",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "debug": "node --inspect-brk ../../vite/bin/vite"
+  }
+}

packages/playground/define/vite.config.js

@@ -0,0 +1,13 @@
+module.exports = {
+  define: {
+    __STRING__: 'hello',
+    __NUMBER__: 123,
+    __BOOLEAN__: true,
+    __OBJ__: {
+      foo: 1,
+      bar: {
+        baz: 2
+      }
+    }
+  }
+}

packages/vite/src/node/plugins/define.ts

@@ -10,6 +10,11 @@ import { isCSSRequest } from './css'
  * to avoid transform cost during dev.
  */
 export function buildDefinePlugin(config: ResolvedConfig): Plugin {
+  const userDefine: Record<string, string> = {}
+  for (const key in config.define) {
+    userDefine[key] = JSON.stringify(config.define[key])
+  }
+
   const individualEnvKeys: Record<string, string> = {}
   for (const key in config.env) {
     individualEnvKeys[`import.meta.env.${key}`] = JSON.stringify(
@@ -18,7 +23,7 @@ export function buildDefinePlugin(config: ResolvedConfig): Plugin {
   }
 
   const replacements: Record<string, string | undefined> = {
-    ...config.define,
+    ...userDefine,
     ...individualEnvKeys,
     'import.meta.env.': `({}).`,
     'import.meta.env': JSON.stringify(config.env),