From 48af7442dce3ce188b0332f35021d5f60f7aa8bb Mon Sep 17 00:00:00 2001
From: Niklas Mischkulnig <4586894+mischnic@users.noreply.github.com>
Date: Fri, 27 Oct 2023 20:37:54 +0200
Subject: [PATCH 1/2] Init Wasm module only once in browsers

---
 wasm/index.mjs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/wasm/index.mjs b/wasm/index.mjs
index 0b049b50..6f948787 100644
--- a/wasm/index.mjs
+++ b/wasm/index.mjs
@@ -4,6 +4,8 @@ import { await_promise_sync, createBundleAsync } from './async.mjs';
 let wasm, bundleAsyncInternal;
 
 export default async function init(input) {
+  if (wasm) return;
+
   input = input ?? new URL('lightningcss_node.wasm', import.meta.url);
   if (typeof input === 'string' || (typeof Request === 'function' && input instanceof Request) || (typeof URL === 'function' && input instanceof URL)) {
     input = fetchOrReadFromFs(input);

From f1685496aa2b65a90561e857948a383c77cf5a10 Mon Sep 17 00:00:00 2001
From: Niklas Mischkulnig <4586894+mischnic@users.noreply.github.com>
Date: Sat, 28 Oct 2023 14:36:02 +0200
Subject: [PATCH 2/2] Init Wasm only once when loading multiple times

---
 wasm/index.mjs | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/wasm/index.mjs b/wasm/index.mjs
index 6f948787..aba5596d 100644
--- a/wasm/index.mjs
+++ b/wasm/index.mjs
@@ -1,26 +1,29 @@
 import { Environment, napi } from 'napi-wasm';
 import { await_promise_sync, createBundleAsync } from './async.mjs';
 
-let wasm, bundleAsyncInternal;
+let wasm, initPromise, bundleAsyncInternal;
 
 export default async function init(input) {
   if (wasm) return;
+  if (initPromise) {
+    await initPromise;
+    return;
+  }
 
   input = input ?? new URL('lightningcss_node.wasm', import.meta.url);
   if (typeof input === 'string' || (typeof Request === 'function' && input instanceof Request) || (typeof URL === 'function' && input instanceof URL)) {
     input = fetchOrReadFromFs(input);
   }
 
-  const { instance } = await load(await input, {
-    env: {
-      ...napi,
-      await_promise_sync
-    }
-  });
+  initPromise = input
+    .then(input => load(input, {env: {...napi, await_promise_sync}}))
+    .then(({instance}) => {
+      let env = new Environment(instance);
+      bundleAsyncInternal = createBundleAsync(env);
+      wasm = env.exports;
+    });
 
-  let env = new Environment(instance);
-  wasm = env.exports;
-  bundleAsyncInternal = createBundleAsync(env);
+  await initPromise;
 }
 
 export function transform(options) {