breaking: remove polyfills & top level await (#41)

* breaking: make fetch-blob an optional dependency

also lazy load fetch-blob when necessary

* breaking: now depend on built-in DOMException

* remove all polyfills

* breaking summary

Author: jimmywarting

README.md

@@ -33,6 +33,35 @@ It's not trying to interfere with the changing spec by using other properties th
 ( The current minium supported browser I have chosen to support is the ones that can handle import/export )<br>
 ( Some parts are lazy loaded when needed )
 
+### Updating from 2.x to 3.x
+v3 removed all top level await that conditionally loaded polyfills like
+WritableStream, DOMException, and Blob/File. considering that now all latest
+up to date env have this built in globally on `globalThis` namespace. This makes
+the file system adapter lighter for ppl who want a smaller bundle and supports
+newer engines.
+
+But if you still need to provide polyfills for older environments
+then you can provide your own polyfill and set it up with our config before any
+other script is evaluated
+
+```js
+
+import config from 'native-file-system-adapter/config.js'
+// This is the default config that you could override as needed.
+Object.assign(config, {
+  ReadableStream: globalThis.ReadableStream,
+  WritableStream: globalThis.WritableStream,
+  TransformStream: globalThis.TransformStream,
+  DOMException: globalThis.DOMException,
+  Blob: globalThis.Blob,
+  File: globalThis.File
+})
+// continue like normal.
+import xyz from 'native-file-system-adapter'
+```
+
+
+
 ### ES import in browser
 
 ```html

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "native-file-system-adapter",
-  "version": "2.0.3",
+  "version": "3.0.0",
   "description": "Native File System API",
   "main": "src/es6.js",
   "module": "./src/es6.js",
@@ -49,11 +49,7 @@
   ],
   "homepage": "https://github.com/jimmywarting/native-file-system-adapter#readme",
   "optionalDependencies": {
-    "web-streams-polyfill": "^3.1.1"
-  },
-  "dependencies": {
-    "fetch-blob": "^3.1.5",
-    "node-domexception": "^1.0.0"
+    "fetch-blob": "^3.2.0"
   },
   "standard": {
     "globals": [

package.json

@@ -1,8 +1,8 @@
-/** @type {typeof WritableStream} */
-const ws = globalThis.WritableStream || await import('https://cdn.jsdelivr.net/npm/web-streams-polyfill@3/dist/ponyfill.es2018.mjs').then(r => r.WritableStream).catch(() => import('web-streams-polyfill').then(r => r.WritableStream))
+import config from './config.js'
 
-// TODO: add types for ws
-class FileSystemWritableFileStream extends ws {
+const { WritableStream } = config
+
+class FileSystemWritableFileStream extends WritableStream {
   constructor (...args) {
     super(...args)
 

src/FileSystemWritableFileStream.js

@@ -1,12 +1,18 @@
 /* global Blob, DOMException, Response, MessageChannel */
 
 import { errors } from '../util.js'
+import config from '../config.js'
+
+const {
+  WritableStream,
+  TransformStream,
+  DOMException,
+  Blob
+} = config
 
 const { GONE } = errors
 // @ts-ignore
 const isSafari = /constructor/i.test(window.HTMLElement) || window.safari || window.WebKitPoint
-let TransformStream = globalThis.TransformStream
-let WritableStream = globalThis.WritableStream
 
 export class FileHandle {
   constructor (name = 'unkown') {
@@ -26,12 +32,6 @@ export class FileHandle {
    * @param {object} [options={}]
    */
   async createWritable (options = {}) {
-    if (!TransformStream) {
-      // @ts-ignore
-      const ponyfill = await import('https://cdn.jsdelivr.net/npm/web-streams-polyfill@3/dist/ponyfill.es2018.mjs')
-      TransformStream = ponyfill.TransformStream
-      WritableStream = ponyfill.WritableStream
-    }
     const sw = await navigator.serviceWorker?.getRegistration()
     const link = document.createElement('a')
     const ts = new TransformStream()

src/adapters/downloader.js

@@ -1,9 +1,7 @@
 import { errors } from '../util.js'
-/** @type {typeof window.File} */
-const File = globalThis.File || await import('fetch-blob/file.js').then(m => m.File)
-/** @type {typeof window.Blob} */
-const Blob = globalThis.Blob || await import('fetch-blob').then(m => m.Blob)
+import config from '../config.js'
 
+const { File, Blob, DOMException } = config
 const { INVALID, GONE, MISMATCH, MOD_ERR, SYNTAX, SECURITY, DISALLOWED } = errors
 
 export class Sink {

src/adapters/memory.js

@@ -1,15 +1,34 @@
 import fs from 'node:fs/promises'
 import { join } from 'node:path'
-import 'node-domexception'
-import Blob from 'fetch-blob'
-import { fileFrom } from 'fetch-blob/from.js'
 import { errors } from '../util.js'
-// import mime from 'mime-types'
+
+import config from '../config.js'
+
+const {
+  DOMException
+} = config
 
 const { INVALID, GONE, MISMATCH, MOD_ERR, SYNTAX } = errors
 
-export class Sink {
+/**
+ * @see https://github.com/node-fetch/fetch-blob/blob/0455796ede330ecffd9eb6b9fdf206cc15f90f3e/index.js#L232
+ * @param {*} object
+ * @returns {object is Blob}
+ */
+function isBlob (object) {
+  return (
+    object &&
+    typeof object === 'object' &&
+    typeof object.constructor === 'function' &&
+    (
+      typeof object.stream === 'function' ||
+      typeof object.arrayBuffer === 'function'
+    ) &&
+    /^(Blob|File)$/.test(object[Symbol.toStringTag])
+  )
+}
 
+export class Sink {
   /**
    * @param {fs.FileHandle} fileHandle
    * @param {number} size
@@ -65,7 +84,7 @@ export class Sink {
       chunk = new Uint8Array(chunk)
     } else if (typeof chunk === 'string') {
       chunk = Buffer.from(chunk)
-    } else if (chunk instanceof Blob) {
+    } else if (isBlob(chunk)) {
       for await (const data of chunk.stream()) {
         const res = await this._fileHandle.writev([data], this._position)
         this._position += res.bytesWritten
@@ -101,6 +120,9 @@ export class FileHandle {
     await fs.stat(this._path).catch(err => {
       if (err.code === 'ENOENT') throw new DOMException(...GONE)
     })
+
+    // TODO: replace once https://github.com/nodejs/node/issues/37340 is fixed
+    const { fileFrom } = await import('fetch-blob/from.js')
     return fileFrom(this._path)
   }
 

src/adapters/node.js

@@ -0,0 +1,10 @@
+const config = {
+  ReadableStream: globalThis.ReadableStream,
+  WritableStream: globalThis.WritableStream,
+  TransformStream: globalThis.TransformStream,
+  DOMException: globalThis.DOMException,
+  Blob: globalThis.Blob,
+  File: globalThis.File,
+}
+
+export default config

src/config.js

@@ -1,6 +1,8 @@
 import { existsSync, mkdirSync, rmdirSync } from 'node:fs'
-import { getOriginPrivateDirectory } from '../src/es6.js'
+import config from '../src/config.js'
 import steps from './test.js'
+import File from 'fetch-blob/file.js'
+import { getOriginPrivateDirectory } from '../src/es6.js'
 import { cleanupSandboxedFileSystem } from '../test/util.js'
 
 let hasFailures = false
@@ -12,6 +14,7 @@ async function test (fs, step, root) {
     console.log(`[OK]: ${fs} ${step.desc}`)
   } catch (err) {
     console.log(`[ERR]: ${fs} ${step.desc}\n\t-> ${err.message}`)
+    console.error(err.stack)
     hasFailures = true
   }
 }
@@ -21,6 +24,7 @@ async function start () {
   if (!existsSync(testFolderPath)) {
     mkdirSync(testFolderPath)
   }
+  config.File = File
   const root = await getOriginPrivateDirectory(import('../src/adapters/node.js'), './testfolder')
   const memory = await getOriginPrivateDirectory(import('../src/adapters/memory.js'))