From ef114ecf75411dd310770ca687da24432bd433bf Mon Sep 17 00:00:00 2001
From: Devon Govett <devongovett@gmail.com>
Date: Sat, 19 Aug 2023 15:28:04 -0700
Subject: [PATCH] Instantiate wasm synchronously

---
 README.md       |  9 ++-----
 package.json    |  2 +-
 test/since.js   |  1 -
 test/watcher.js |  1 -
 wasm/index.mjs  | 62 ++++++++-----------------------------------------
 5 files changed, 13 insertions(+), 62 deletions(-)

diff --git a/README.md b/README.md
index c5f0037..5c34150 100644
--- a/README.md
+++ b/README.md
@@ -112,20 +112,15 @@ All of the APIs in `@parcel/watcher` support the following options, which are pa
 
 The `@parcel/watcher-wasm` package can be used in place of `@parcel/watcher` on unsupported platforms. It relies on the Node `fs` module, so in non-Node environments such as browsers, an `fs` polyfill will be needed. The `@parcel/watcher-wasm` package is published as an ESM-only module.
 
-The WASM API is identical, except you must initialize it first.
+**Note**: the WASM implementation is significantly less efficient than the native implementations because it must crawl the file system to watch each directory individually. Use the native `@parcel/watcher` package wherever possible.
 
 ```js
-import init, {subscribe} from '@parcel/watcher-wasm';
-
-// Load and initialize the WASM module.
-await init();
+import {subscribe} from '@parcel/watcher-wasm';
 
 // Use the module as documented above.
 subscribe(/* ... */);
 ```
 
-By default, `init` loads the WASM file relative to its JavaScript, but you can pass a URL to the `watcher.wasm` file if you are hosting it elsewhere.
-
 ## Who is using this?
 
 - [Parcel 2](https://parceljs.org/)
diff --git a/package.json b/package.json
index 32efdd4..b5c1656 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@parcel/watcher",
-  "version": "2.3.0-alpha.1",
+  "version": "2.3.0-alpha.2",
   "main": "index.js",
   "types": "index.d.ts",
   "repository": {
diff --git a/test/since.js b/test/since.js
index 547b9c3..c3db999 100644
--- a/test/since.js
+++ b/test/since.js
@@ -59,7 +59,6 @@ describe('since', () => {
         if (backend === 'wasm') {
           if (!watcherWasm) {
             watcherWasm = await import('../wasm/index.mjs');
-            await watcherWasm.default();
           }
           watcher = watcherWasm;
         } else {
diff --git a/test/watcher.js b/test/watcher.js
index ee7dd62..b9f3a40 100644
--- a/test/watcher.js
+++ b/test/watcher.js
@@ -60,7 +60,6 @@ describe('watcher', () => {
       before(async () => {
         if (backend === 'wasm') {
           watcher = await import('../wasm/index.mjs');
-          await watcher.default();
         } else {
           watcher = watcherNative;
         }
diff --git a/wasm/index.mjs b/wasm/index.mjs
index 5f821a0..67cfcae 100644
--- a/wasm/index.mjs
+++ b/wasm/index.mjs
@@ -1,11 +1,9 @@
 import { Environment, napi } from 'napi-wasm';
 import fs from 'fs';
 import Path from 'path';
-import micromatch from 'micromatch';
-import isGlob from 'is-glob';
 import { createWrapper } from '../wrapper.js';
 
-let wrapper, env;
+let env;
 let encoder = new TextEncoder;
 
 let constants = {
@@ -300,56 +298,16 @@ function align(len, p) {
   return Math.ceil(len / p) * p;
 }
 
-export default async function init(input) {
-  input = input ?? new URL('../build/Debug/watcher.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, {
-    napi,
-    env: wasm_env,
-    wasi_snapshot_preview1: wasi
-  });
-
-  env = new Environment(instance);
-  wrapper = createWrapper(env.exports);
-}
-
-async function load(module, imports) {
-  if (typeof Response === 'function' && module instanceof Response) {
-    if (typeof WebAssembly.instantiateStreaming === 'function') {
-      try {
-        return await WebAssembly.instantiateStreaming(module, imports);
-      } catch (e) {
-        if (module.headers.get('Content-Type') != 'application/wasm') {
-          console.warn("`WebAssembly.instantiateStreaming` failed because your server does not serve wasm with `application/wasm` MIME type. Falling back to `WebAssembly.instantiate` which is slower. Original error:\n", e);
-        } else {
-          throw e;
-        }
-      }
-    }
+let wasmBytes = fs.readFileSync(new URL('../build/Debug/watcher.wasm', import.meta.url));
+let wasmModule = new WebAssembly.Module(wasmBytes);
+let instance = new WebAssembly.Instance(wasmModule, {
+  napi,
+  env: wasm_env,
+  wasi_snapshot_preview1: wasi
+});
 
-    const bytes = await module.arrayBuffer();
-    return await WebAssembly.instantiate(bytes, imports);
-  } else {
-    const instance = await WebAssembly.instantiate(module, imports);
-    if (instance instanceof WebAssembly.Instance) {
-      return { instance, module };
-    } else {
-      return instance;
-    }
-  }
-}
-
-async function fetchOrReadFromFs(inputPath) {
-  try {
-    const fs = await import('fs');
-    return fs.readFileSync(inputPath);
-  } catch {
-    return fetch(inputPath);
-  }
-}
+env = new Environment(instance);
+let wrapper = createWrapper(env.exports);
 
 export function writeSnapshot(dir, snapshot, opts) {
   return wrapper.writeSnapshot(dir, snapshot, opts);