fix: avoid reading files when the size is empty (#134)

* fix: avoid reading files when the size is empty

* also use stat.size for checking if it is modified

* bump minor version number

* Don't push empty chunks into the array (creates faster reads)

* reverted back to avoid making a if check

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,24 @@
+<!-- Thanks for contributing! -->
+
+## The purpose of this PR is:
+...
+
+## This is what had to change:
+...
+
+## This is what like reviewers to know:
+...
+
+
+-------------------------------------------------------------------------------------------------
+
+<!-- Mark what you have done, Remove unnecessary ones. Add new tasks that may fit (like TODO's) -->
+- [ ] I prefixed the PR-title with `docs: `, `fix(area): `, `feat(area): ` or `breaking(area): `
+- [ ] I updated ./CHANGELOG.md with a link to this PR or Issue
+- [ ] I updated the README.md
+- [ ] I Added unit test(s)
+
+-------------------------------------------------------------------------------------------------
+
+<!-- Add a `- fix #_NUMBER_` line for every Issue this PR solves. Do not comma separate them -->
+- fix #000

.github/dependabot.yml

@@ -0,0 +1,25 @@
+version: 2
+updates:
+- package-ecosystem: npm
+  directory: "/"
+  schedule:
+    interval: daily
+  open-pull-requests-limit: 10
+  ignore:
+  - dependency-name: get-stream
+    versions:
+    - 6.0.0
+    - 6.0.1
+  - dependency-name: typescript
+    versions:
+    - 4.1.3
+    - 4.1.4
+    - 4.1.5
+    - 4.2.2
+    - 4.2.3
+    - 4.2.4
+  - dependency-name: xo
+    versions:
+    - 0.37.1
+    - 0.38.1
+    - 0.38.2

.github/workflows/ci.yml

@@ -14,43 +14,18 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macOS-latest]
-        node: ["14", "12", engines]
-        exclude:
-          # On Windows, run tests with only the LTS environments.
-          - os: windows-latest
-            node: engines
-          - os: windows-latest
-            node: "14"
-          # On macOS, run tests with only the LTS environments.
-          - os: macOS-latest
-            node: engines
-          - os: macOS-latest
-            node: "14"
+        node: ["17.3"]
 
     runs-on: ${{ matrix.os }}
+
     steps:
       - uses: actions/checkout@v2
-
-      - name: Get Node.JS version from package.json
-        if: matrix.node == 'engines'
-        id: get-version
-        run: echo ::set-output name=node::$(npx --q minimum-node-version)
-
-      - uses: actions/setup-node@v2-beta
-        if: matrix.node != 'engines'
+      - uses: actions/setup-node@v2
         with:
-          node-version: ${{ matrix.node }}
-
-      - uses: actions/setup-node@v2-beta
-        if: matrix.node == 'engines'
-        with:
-          node-version: ${{steps.get-version.outputs.node}}
-
+          node-version: '17.3'
       - run: npm install
-      - run: npm install domexception
-
+      - run: npm test
       - run: npm run report -- --colors
-
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v1
         with:

.github/workflows/lint.yml

@@ -1,20 +0,0 @@
-name: CI
-
-on:
-  pull_request:
-    paths:
-      - "**.js"
-      - "**eslint**"
-      - "package.json"
-      - ".github/workflows/lint.yml"
-jobs:
-  lint:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: Use Node.js
-        uses: actions/setup-node@v2-beta
-        with:
-          node-version: 14
-      - run: npm install
-      - run: npm run lint

.gitignore

@@ -16,6 +16,8 @@ pids
 *.seed
 *.pid.lock
 
+
+
 # Directory for instrumented libs generated by jscoverage/JSCover
 lib-cov
 
@@ -47,8 +49,8 @@ typings/
 # Optional npm cache directory
 .npm
 
-# Optional eslint cache
-.eslintcache
+# Optional cache
+.cache
 
 # Optional REPL history
 .node_repl_history
@@ -62,4 +64,6 @@ typings/
 # dotenv environment variables file
 .env
 
-index.d.ts
+*.d.ts
+*.d.cts
+.DS_Store

CHANGELOG.md

@@ -1,5 +1,49 @@
-Changelog
-=========
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/) and this
+project adheres to [Semantic Versioning](http://semver.org/).
+
+## v3.1.3
+- Allow usage of iterable object in Blob constructor. [#108]
+- Run test WPT test against our impl [#109]
+- File name are now casted to string [#109]
+- Slicing in the middle of multiple parts added more bytes than what what it should have [#109]
+- Prefixed `stream/web` import with `node:` to allow easier static analysis detection of Node built-ins [#122]
+- Added `node:` prefix in `from.js` as well [#114]
+- Suppress warning when importing `stream/web` [#114]
+
+## v3.1.2
+- Improved typing
+- Fixed a bug where position in iterator did not increase
+
+## v3.1.0
+- started to use real whatwg streams
+- degraded fs/promise to fs.promise to support node v12
+- degraded optional changing to support node v12
+
+## v3.0.0
+- Changed WeakMap for private field (require node 12)
+- Switch to ESM
+- blob.stream() return a subset of whatwg stream which is the async iterable part
+  (it no longer return a node stream)
+- Reduced the dependency of Buffer by changing to global TextEncoder/Decoder (require node 11)
+- Disabled xo since it could understand private fields (#)
+- No longer transform the type to lowercase (https://github.com/w3c/FileAPI/issues/43)
+  This is more loose than strict, keys should be lowercased, but values should not.
+  It would require a more proper mime type parser - so we just made it loose.
+- index.js and file.js can now be imported by browser & deno since it no longer depends on any
+  core node features (but why would you?)
+- Implemented a File class
+
+## v2.1.2
+- Fixed a bug where `start` in BlobDataItem was undefined (#85)
+
+## v2.1.1
+- Add nullish values checking in Symbol.hasInstance (#82)
+- Add generated typings for from.js file (#80)
+- Updated dev dependencies
 
 ## v2.1.0
 - Fix: .slice has an implementation bug (#54).
@@ -48,3 +92,7 @@ Changelog
 ## v1.0.0
 
 - Major: initial release
+
+[#108]: https://github.com/node-fetch/fetch-blob/pull/108
+[#109]: https://github.com/node-fetch/fetch-blob/pull/109
+[#114]: https://github.com/node-fetch/fetch-blob/pull/114

README.md

@@ -13,39 +13,87 @@ A Blob implementation in Node.js, originally from [node-fetch](https://github.co
 npm install fetch-blob
 ```
 
+<details>
+  <summary>Upgrading from 2x to 3x</summary>
+
+  Updating from 2 to 3 should be a breeze since there is not many changes to the blob specification.
+  The major cause of a major release is coding standards.
+    - internal WeakMaps was replaced with private fields
+    - internal Buffer.from was replaced with TextEncoder/Decoder
+    - internal buffers was replaced with Uint8Arrays
+    - CommonJS was replaced with ESM
+    - The node stream returned by calling `blob.stream()` was replaced with whatwg streams
+    - (Read "Differences from other blobs" for more info.)
+
+</details>
+
+<details>
+  <summary>Differences from other Blobs</summary>
+
+  - Unlike NodeJS `buffer.Blob` (Added in: v15.7.0) and browser native Blob this polyfilled version can't be sent via PostMessage
+  - This blob version is more arbitrary, it can be constructed with blob parts that isn't a instance of itself
+  it has to look and behave as a blob to be accepted as a blob part.
+    - The benefit of this is that you can create other types of blobs that don't contain any internal data that has to be read in other ways, such as the `BlobDataItem` created in `from.js` that wraps a file path into a blob-like item and read lazily (nodejs plans to [implement this][fs-blobs] as well)
+  - The `blob.stream()` is the most noticeable differences. It returns a WHATWG stream now. to keep it as a node stream you would have to do:
+
+  ```js
+    import {Readable} from 'stream'
+    const stream = Readable.from(blob.stream())
+  ```
+</details>
+
 ## Usage
 
 ```js
-const Blob = require('fetch-blob');
-const fetch = require('node-fetch');
+// Ways to import
+// (PS it's dependency free ESM package so regular http-import from CDN works too)
+import Blob from 'fetch-blob'
+import File from 'fetch-blob/file.js'
 
-fetch('https://httpbin.org/post', {
-    method: 'POST',
-    body: new Blob(['Hello World'], { type: 'text/plain' })
-})
-    .then(res => res.json());
-    .then(json => console.log(json));
+import {Blob} from 'fetch-blob'
+import {File} from 'fetch-blob/file.js'
+
+const {Blob} = await import('fetch-blob')
+
+
+// Ways to read the blob:
+const blob = new Blob(['hello, world'])
+
+await blob.text()
+await blob.arrayBuffer()
+for await (let chunk of  blob.stream()) { ... }
+blob.stream().getReader().read()
+blob.stream().getReader({mode: 'byob'}).read(view)
 ```
 
 ### Blob part backed up by filesystem
-To use, install [domexception](https://github.com/jsdom/domexception).
 
-```sh
-npm install fetch-blob domexception
-```
+`fetch-blob/from.js` comes packed with tools to convert any filepath into either a Blob or a File
+It will not read the content into memory. It will only stat the file for last modified date and file size.
 
 ```js
-const blobFrom = require('fetch-blob/from.js');
-const blob1 = blobFrom('./2-GiB-file.bin');
-const blob2 = blobFrom('./2-GiB-file.bin');
+// The default export is sync and use fs.stat to retrieve size & last modified as a blob
+import blobFromSync from 'fetch-blob/from.js'
+import {File, Blob, blobFrom, blobFromSync, fileFrom, fileFromSync} from 'fetch-blob/from.js'
 
-// Not a 4 GiB memory snapshot, just holds 3 references
+const fsFile = fileFromSync('./2-GiB-file.bin', 'application/octet-stream')
+const fsBlob = await blobFrom('./2-GiB-file.mp4')
+
+// Not a 4 GiB memory snapshot, just holds references
 // points to where data is located on the disk
-const blob = new Blob([blob1, blob2]);
-console.log(blob.size) // 4 GiB
+const blob = new Blob([fsFile, fsBlob, 'memory', new Uint8Array(10)])
+console.log(blob.size) // ~4 GiB
 ```
 
-See the [MDN documentation](https://developer.mozilla.org/en-US/docs/Web/API/Blob) and [tests](https://github.com/node-fetch/fetch-blob/blob/master/test.js) for more details.
+`blobFrom|blobFromSync|fileFrom|fileFromSync(path, [mimetype])`
+
+### Creating Blobs backed up by other async sources
+Our Blob & File class are more generic then any other polyfills in the way that it can accept any blob look-a-like item
+An example of this is that our blob implementation can be constructed with parts coming from [BlobDataItem](https://github.com/node-fetch/fetch-blob/blob/8ef89adad40d255a3bbd55cf38b88597c1cd5480/from.js#L32) (aka a filepath) or from [buffer.Blob](https://nodejs.org/api/buffer.html#buffer_new_buffer_blob_sources_options), It dose not have to implement all the methods - just enough that it can be read/understood by our Blob implementation. The minium requirements is that it has `Symbol.toStringTag`, `size`, `slice()` and either a `stream()` or a `arrayBuffer()` method. If you then wrap it in our Blob or File `new Blob([blobDataItem])` then you get all of the other methods that should be implemented in a blob or file
+
+An example of this could be to create a file or blob like item coming from a remote HTTP request. Or from a DataBase
+
+See the [MDN documentation](https://developer.mozilla.org/en-US/docs/Web/API/Blob) and [tests](https://github.com/node-fetch/fetch-blob/blob/master/test.js) for more details of how to use the Blob.
 
 [npm-image]: https://flat.badgen.net/npm/v/fetch-blob
 [npm-url]: https://www.npmjs.com/package/fetch-blob
@@ -55,3 +103,4 @@ See the [MDN documentation](https://developer.mozilla.org/en-US/docs/Web/API/Blo
 [codecov-url]: https://codecov.io/gh/node-fetch/fetch-blob
 [install-size-image]: https://flat.badgen.net/packagephobia/install/fetch-blob
 [install-size-url]: https://packagephobia.now.sh/result?p=fetch-blob
+[fs-blobs]: https://github.com/nodejs/node/issues/37340

file.js

@@ -0,0 +1,49 @@
+import Blob from './index.js'
+
+const _File = class File extends Blob {
+  #lastModified = 0
+  #name = ''
+
+  /**
+   * @param {*[]} fileBits
+   * @param {string} fileName
+   * @param {{lastModified?: number, type?: string}} options
+   */// @ts-ignore
+  constructor (fileBits, fileName, options = {}) {
+    if (arguments.length < 2) {
+      throw new TypeError(`Failed to construct 'File': 2 arguments required, but only ${arguments.length} present.`)
+    }
+    super(fileBits, options)
+
+    if (options === null) options = {}
+
+    // Simulate WebIDL type casting for NaN value in lastModified option.
+    const lastModified = options.lastModified === undefined ? Date.now() : Number(options.lastModified)
+    if (!Number.isNaN(lastModified)) {
+      this.#lastModified = lastModified
+    }
+
+    this.#name = String(fileName)
+  }
+
+  get name () {
+    return this.#name
+  }
+
+  get lastModified () {
+    return this.#lastModified
+  }
+
+  get [Symbol.toStringTag] () {
+    return 'File'
+  }
+
+  static [Symbol.hasInstance] (object) {
+    return !!object && object instanceof Blob &&
+      /^(File)$/.test(object[Symbol.toStringTag])
+  }
+}
+
+/** @type {typeof globalThis.File} */// @ts-ignore
+export const File = _File
+export default File

from.js

@@ -1,57 +1,106 @@
-const {statSync, createReadStream} = require('fs');
-const Blob = require('.');
-const DOMException = require('domexception');
+import { statSync, createReadStream, promises as fs } from 'node:fs'
+import { basename } from 'node:path'
+import DOMException from 'node-domexception'
+
+import File from './file.js'
+import Blob from './index.js'
+
+const { stat } = fs
 
 /**
  * @param {string} path filepath on the disk
- * @returns {Blob}
+ * @param {string} [type] mimetype to use
  */
-function blobFrom(path) {
-	const {size, mtime} = statSync(path);
-	const blob = new BlobDataItem({path, size, mtime});
+const blobFromSync = (path, type) => fromBlob(statSync(path), path, type)
 
-	return new Blob([blob]);
-}
+/**
+ * @param {string} path filepath on the disk
+ * @param {string} [type] mimetype to use
+ * @returns {Promise<Blob>}
+ */
+const blobFrom = (path, type) => stat(path).then(stat => fromBlob(stat, path, type))
+
+/**
+ * @param {string} path filepath on the disk
+ * @param {string} [type] mimetype to use
+ * @returns {Promise<File>}
+ */
+const fileFrom = (path, type) => stat(path).then(stat => fromFile(stat, path, type))
+
+/**
+ * @param {string} path filepath on the disk
+ * @param {string} [type] mimetype to use
+ */
+const fileFromSync = (path, type) => fromFile(statSync(path), path, type)
+
+// @ts-ignore
+const fromBlob = (stat, path, type = '') => new Blob([new BlobDataItem({
+  path,
+  size: stat.size,
+  lastModified: stat.mtimeMs,
+  start: 0
+})], { type })
+
+// @ts-ignore
+const fromFile = (stat, path, type = '') => new File([new BlobDataItem({
+  path,
+  size: stat.size,
+  lastModified: stat.mtimeMs,
+  start: 0
+})], basename(path), { type, lastModified: stat.mtimeMs })
 
 /**
  * This is a blob backed up by a file on the disk
- * with minium requirement
+ * with minium requirement. Its wrapped around a Blob as a blobPart
+ * so you have no direct access to this.
  *
  * @private
  */
 class BlobDataItem {
-	constructor(options) {
-		this.size = options.size;
-		this.path = options.path;
-		this.start = options.start;
-		this.mtime = options.mtime;
-	}
+  #path
+  #start
 
-	// Slicing arguments is validated and formated
-	// by Blob.prototype.slice
-	slice(start, end) {
-		return new BlobDataItem({
-			path: this.path,
-			start,
-			mtime: this.mtime,
-			size: end - start
-		});
-	}
+  constructor (options) {
+    this.#path = options.path
+    this.#start = options.start
+    this.size = options.size
+    this.lastModified = options.lastModified
+    this.originalSize = options.originalSize === undefined
+      ? options.size
+      : options.originalSize
+  }
 
-	stream() {
-		if (statSync(this.path).mtime > this.mtime) {
-			throw new DOMException('The requested file could not be read, typically due to permission problems that have occurred after a reference to a file was acquired.', 'NotReadableError');
-		}
+  /**
+   * Slicing arguments is first validated and formatted
+   * to not be out of range by Blob.prototype.slice
+   */
+  slice (start, end) {
+    return new BlobDataItem({
+      path: this.#path,
+      lastModified: this.lastModified,
+      originalSize: this.originalSize,
+      size: end - start,
+      start: this.#start + start
+    })
+  }
 
-		return createReadStream(this.path, {
-			start: this.start,
-			end: this.start + this.size - 1
-		});
-	}
+  async * stream () {
+    const { mtimeMs, size } = await stat(this.#path)
 
-	get [Symbol.toStringTag]() {
-		return 'Blob';
-	}
+    if (mtimeMs > this.lastModified || this.originalSize !== size) {
+      throw new DOMException('The requested file could not be read, typically due to permission problems that have occurred after a reference to a file was acquired.', 'NotReadableError')
+    }
+
+    yield * createReadStream(this.#path, {
+      start: this.#start,
+      end: this.#start + this.size - 1
+    })
+  }
+
+  get [Symbol.toStringTag] () {
+    return 'Blob'
+  }
 }
 
-module.exports = blobFrom;
+export default blobFromSync
+export { File, Blob, blobFrom, blobFromSync, fileFrom, fileFromSync }

index.js

@@ -1,178 +1,254 @@
-const {Readable} = require('stream');
+/*! fetch-blob. MIT License. Jimmy Wärting <https://jimmy.warting.se/opensource> */
 
-/**
- * @type {WeakMap<Blob, {type: string, size: number, parts: (Blob | Buffer)[] }>}
- */
-const wm = new WeakMap();
+// TODO (jimmywarting): in the feature use conditional loading with top level await (requires 14.x)
+// Node has recently added whatwg stream into core
 
-async function * read(parts) {
-	for (const part of parts) {
-		if ('stream' in part) {
-			yield * part.stream();
-		} else {
-			yield part;
-		}
-	}
+import './streams.cjs'
+
+// 64 KiB (same size chrome slice theirs blob into Uint8array's)
+const POOL_SIZE = 65536
+
+/** @param {(Blob | Uint8Array)[]} parts */
+async function * toIterator (parts, clone = true) {
+  for (const part of parts) {
+    if ('stream' in part) {
+      yield * (/** @type {AsyncIterableIterator<Uint8Array>} */ (part.stream()))
+    } else if (ArrayBuffer.isView(part)) {
+      if (clone) {
+        let position = part.byteOffset
+        const end = part.byteOffset + part.byteLength
+        while (position !== end) {
+          const size = Math.min(end - position, POOL_SIZE)
+          const chunk = part.buffer.slice(position, position + size)
+          position += chunk.byteLength
+          yield new Uint8Array(chunk)
+        }
+      } else {
+        yield part
+      }
+    /* c8 ignore next 10 */
+    } else {
+      // For blobs that have arrayBuffer but no stream method (nodes buffer.Blob)
+      let position = 0, b = (/** @type {Blob} */ (part))
+      while (position !== b.size) {
+        const chunk = b.slice(position, Math.min(b.size, position + POOL_SIZE))
+        const buffer = await chunk.arrayBuffer()
+        position += buffer.byteLength
+        yield new Uint8Array(buffer)
+      }
+    }
+  }
 }
 
-class Blob {
-	/**
-	 * The Blob() constructor returns a new Blob object. The content
-	 * of the blob consists of the concatenation of the values given
-	 * in the parameter array.
-	 *
-	 * @param {(ArrayBufferLike | ArrayBufferView | Blob | Buffer | string)[]} blobParts
-	 * @param {{ type?: string }} [options]
-	 */
-	constructor(blobParts = [], options = {type: ''}) {
-		let size = 0;
+const _Blob = class Blob {
+  /** @type {Array.<(Blob|Uint8Array)>} */
+  #parts = []
+  #type = ''
+  #size = 0
+  #endings = 'transparent'
 
-		const parts = blobParts.map(element => {
-			let buffer;
-			if (element instanceof Buffer) {
-				buffer = element;
-			} else if (ArrayBuffer.isView(element)) {
-				buffer = Buffer.from(element.buffer, element.byteOffset, element.byteLength);
-			} else if (element instanceof ArrayBuffer) {
-				buffer = Buffer.from(element);
-			} else if (element instanceof Blob) {
-				buffer = element;
-			} else {
-				buffer = Buffer.from(typeof element === 'string' ? element : String(element));
-			}
+  /**
+   * The Blob() constructor returns a new Blob object. The content
+   * of the blob consists of the concatenation of the values given
+   * in the parameter array.
+   *
+   * @param {*} blobParts
+   * @param {{ type?: string, endings?: string }} [options]
+   */
+  constructor (blobParts = [], options = {}) {
+    if (typeof blobParts !== 'object' || blobParts === null) {
+      throw new TypeError('Failed to construct \'Blob\': The provided value cannot be converted to a sequence.')
+    }
 
-			size += buffer.length || buffer.size || 0;
-			return buffer;
-		});
+    if (typeof blobParts[Symbol.iterator] !== 'function') {
+      throw new TypeError('Failed to construct \'Blob\': The object must have a callable @@iterator property.')
+    }
 
-		const type = options.type === undefined ? '' : String(options.type).toLowerCase();
+    if (typeof options !== 'object' && typeof options !== 'function') {
+      throw new TypeError('Failed to construct \'Blob\': parameter 2 cannot convert to dictionary.')
+    }
 
-		wm.set(this, {
-			type: /[^\u0020-\u007E]/.test(type) ? '' : type,
-			size,
-			parts
-		});
-	}
+    if (options === null) options = {}
 
-	/**
-	 * The Blob interface's size property returns the
-	 * size of the Blob in bytes.
-	 */
-	get size() {
-		return wm.get(this).size;
-	}
+    const encoder = new TextEncoder()
+    for (const element of blobParts) {
+      let part
+      if (ArrayBuffer.isView(element)) {
+        part = new Uint8Array(element.buffer.slice(element.byteOffset, element.byteOffset + element.byteLength))
+      } else if (element instanceof ArrayBuffer) {
+        part = new Uint8Array(element.slice(0))
+      } else if (element instanceof Blob) {
+        part = element
+      } else {
+        part = encoder.encode(`${element}`)
+      }
 
-	/**
-	 * The type property of a Blob object returns the MIME type of the file.
-	 */
-	get type() {
-		return wm.get(this).type;
-	}
+      const size = ArrayBuffer.isView(part) ? part.byteLength : part.size
+      // Avoid pushing empty parts into the array to better GC them
+      if (size) {
+        this.#size += size
+        this.#parts.push(part)
+      }
+    }
 
-	/**
-	 * The text() method in the Blob interface returns a Promise
-	 * that resolves with a string containing the contents of
-	 * the blob, interpreted as UTF-8.
-	 *
-	 * @return {Promise<string>}
-	 */
-	async text() {
-		return Buffer.from(await this.arrayBuffer()).toString();
-	}
+    this.#endings = `${options.endings === undefined ? 'transparent' : options.endings}`
+    const type = options.type === undefined ? '' : String(options.type)
+    this.#type = /^[\x20-\x7E]*$/.test(type) ? type : ''
+  }
 
-	/**
-	 * The arrayBuffer() method in the Blob interface returns a
-	 * Promise that resolves with the contents of the blob as
-	 * binary data contained in an ArrayBuffer.
-	 *
-	 * @return {Promise<ArrayBuffer>}
-	 */
-	async arrayBuffer() {
-		const data = new Uint8Array(this.size);
-		let offset = 0;
-		for await (const chunk of this.stream()) {
-			data.set(chunk, offset);
-			offset += chunk.length;
-		}
+  /**
+   * The Blob interface's size property returns the
+   * size of the Blob in bytes.
+   */
+  get size () {
+    return this.#size
+  }
 
-		return data.buffer;
-	}
+  /**
+   * The type property of a Blob object returns the MIME type of the file.
+   */
+  get type () {
+    return this.#type
+  }
 
-	/**
-	 * The Blob interface's stream() method is difference from native
-	 * and uses node streams instead of whatwg streams.
-	 *
-	 * @returns {Readable} Node readable stream
-	 */
-	stream() {
-		return Readable.from(read(wm.get(this).parts));
-	}
+  /**
+   * The text() method in the Blob interface returns a Promise
+   * that resolves with a string containing the contents of
+   * the blob, interpreted as UTF-8.
+   *
+   * @return {Promise<string>}
+   */
+  async text () {
+    // More optimized than using this.arrayBuffer()
+    // that requires twice as much ram
+    const decoder = new TextDecoder()
+    let str = ''
+    for await (const part of toIterator(this.#parts, false)) {
+      str += decoder.decode(part, { stream: true })
+    }
+    // Remaining
+    str += decoder.decode()
+    return str
+  }
 
-	/**
-	 * The Blob interface's slice() method creates and returns a
-	 * new Blob object which contains data from a subset of the
-	 * blob on which it's called.
-	 *
-	 * @param {number} [start]
-	 * @param {number} [end]
-	 * @param {string} [type]
-	 */
-	slice(start = 0, end = this.size, type = '') {
-		const {size} = this;
+  /**
+   * The arrayBuffer() method in the Blob interface returns a
+   * Promise that resolves with the contents of the blob as
+   * binary data contained in an ArrayBuffer.
+   *
+   * @return {Promise<ArrayBuffer>}
+   */
+  async arrayBuffer () {
+    // Easier way... Just a unnecessary overhead
+    // const view = new Uint8Array(this.size);
+    // await this.stream().getReader({mode: 'byob'}).read(view);
+    // return view.buffer;
 
-		let relativeStart = start < 0 ? Math.max(size + start, 0) : Math.min(start, size);
-		let relativeEnd = end < 0 ? Math.max(size + end, 0) : Math.min(end, size);
+    const data = new Uint8Array(this.size)
+    let offset = 0
+    for await (const chunk of toIterator(this.#parts, false)) {
+      data.set(chunk, offset)
+      offset += chunk.length
+    }
 
-		const span = Math.max(relativeEnd - relativeStart, 0);
-		const parts = wm.get(this).parts.values();
-		const blobParts = [];
-		let added = 0;
+    return data.buffer
+  }
 
-		for (const part of parts) {
-			const size = ArrayBuffer.isView(part) ? part.byteLength : part.size;
-			if (relativeStart && size <= relativeStart) {
-				// Skip the beginning and change the relative
-				// start & end position as we skip the unwanted parts
-				relativeStart -= size;
-				relativeEnd -= size;
-			} else {
-				const chunk = part.slice(relativeStart, Math.min(size, relativeEnd));
-				blobParts.push(chunk);
-				added += ArrayBuffer.isView(chunk) ? chunk.byteLength : chunk.size;
-				relativeStart = 0; // All next sequental parts should start at 0
+  stream () {
+    const it = toIterator(this.#parts, true)
 
-				// don't add the overflow to new blobParts
-				if (added >= span) {
-					break;
-				}
-			}
-		}
+    return new globalThis.ReadableStream({
+      // @ts-ignore
+      type: 'bytes',
+      async pull (ctrl) {
+        const chunk = await it.next()
+        chunk.done ? ctrl.close() : ctrl.enqueue(chunk.value)
+      },
 
-		const blob = new Blob([], {type});
-		Object.assign(wm.get(blob), {size: span, parts: blobParts});
+      async cancel () {
+        await it.return()
+      }
+    })
+  }
 
-		return blob;
-	}
+  /**
+   * The Blob interface's slice() method creates and returns a
+   * new Blob object which contains data from a subset of the
+   * blob on which it's called.
+   *
+   * @param {number} [start]
+   * @param {number} [end]
+   * @param {string} [type]
+   */
+  slice (start = 0, end = this.size, type = '') {
+    const { size } = this
 
-	get [Symbol.toStringTag]() {
-		return 'Blob';
-	}
+    let relativeStart = start < 0 ? Math.max(size + start, 0) : Math.min(start, size)
+    let relativeEnd = end < 0 ? Math.max(size + end, 0) : Math.min(end, size)
 
-	static [Symbol.hasInstance](object) {
-		return (
-			typeof object === 'object' &&
-			typeof object.stream === 'function' &&
-			object.stream.length === 0 &&
-			typeof object.constructor === 'function' &&
-			/^(Blob|File)$/.test(object[Symbol.toStringTag])
-		);
-	}
+    const span = Math.max(relativeEnd - relativeStart, 0)
+    const parts = this.#parts
+    const blobParts = []
+    let added = 0
+
+    for (const part of parts) {
+      // don't add the overflow to new blobParts
+      if (added >= span) {
+        break
+      }
+
+      const size = ArrayBuffer.isView(part) ? part.byteLength : part.size
+      if (relativeStart && size <= relativeStart) {
+        // Skip the beginning and change the relative
+        // start & end position as we skip the unwanted parts
+        relativeStart -= size
+        relativeEnd -= size
+      } else {
+        let chunk
+        if (ArrayBuffer.isView(part)) {
+          chunk = part.subarray(relativeStart, Math.min(size, relativeEnd))
+          added += chunk.byteLength
+        } else {
+          chunk = part.slice(relativeStart, Math.min(size, relativeEnd))
+          added += chunk.size
+        }
+        relativeEnd -= size
+        blobParts.push(chunk)
+        relativeStart = 0 // All next sequential parts should start at 0
+      }
+    }
+
+    const blob = new Blob([], { type: String(type).toLowerCase() })
+    blob.#size = span
+    blob.#parts = blobParts
+
+    return blob
+  }
+
+  get [Symbol.toStringTag] () {
+    return 'Blob'
+  }
+
+  static [Symbol.hasInstance] (object) {
+    return (
+      object &&
+      typeof object === 'object' &&
+      typeof object.constructor === 'function' &&
+      (
+        typeof object.stream === 'function' ||
+        typeof object.arrayBuffer === 'function'
+      ) &&
+      /^(Blob|File)$/.test(object[Symbol.toStringTag])
+    )
+  }
 }
 
-Object.defineProperties(Blob.prototype, {
-	size: {enumerable: true},
-	type: {enumerable: true},
-	slice: {enumerable: true}
-});
+Object.defineProperties(_Blob.prototype, {
+  size: { enumerable: true },
+  type: { enumerable: true },
+  slice: { enumerable: true }
+})
 
-module.exports = Blob;
+/** @type {typeof globalThis.Blob} */
+export const Blob = _Blob
+export default Blob

package.json

@@ -1,55 +1,56 @@
 {
     "name": "fetch-blob",
-    "version": "2.1.0",
-    "description": "A Blob implementation in Node.js, originally from node-fetch.",
+    "version": "3.1.5",
+    "description": "Blob & File implementation in Node.js, originally from node-fetch.",
     "main": "index.js",
+    "type": "module",
     "files": [
         "from.js",
+        "file.js",
+        "file.d.ts",
         "index.js",
-        "index.d.ts"
+        "index.d.ts",
+        "from.d.ts",
+        "streams.cjs"
     ],
     "scripts": {
-        "lint": "xo",
-        "test": "xo && ava",
-        "report": "c8 --reporter json --reporter text ava",
-        "coverage": "c8 --reporter json --reporter text ava && codecov -f coverage/coverage-final.json",
-        "prepublishOnly": "tsc --declaration --emitDeclarationOnly --allowJs index.js"
+        "test": "node --experimental-loader ./test/http-loader.js ./test/test-wpt-in-node.js",
+        "report": "c8 --reporter json --reporter text npm run test",
+        "coverage": "npm run report && codecov -f coverage/coverage-final.json",
+        "prepublishOnly": "tsc --declaration --emitDeclarationOnly --allowJs index.js from.js"
     },
     "repository": "https://github.com/node-fetch/fetch-blob.git",
     "keywords": [
         "blob",
+        "file",
         "node-fetch"
     ],
     "engines": {
-        "node": "^10.17.0 || >=12.3.0"
+        "node": "^12.20 || >= 14.13"
     },
-    "author": "David Frank",
+    "author": "Jimmy Wärting <jimmy@warting.se> (https://jimmy.warting.se)",
     "license": "MIT",
     "bugs": {
         "url": "https://github.com/node-fetch/fetch-blob/issues"
     },
     "homepage": "https://github.com/node-fetch/fetch-blob#readme",
     "devDependencies": {
-        "ava": "^3.8.2",
-        "c8": "^7.2.0",
-        "codecov": "^3.7.0",
-        "get-stream": "^5.1.0",
-        "node-fetch": "^2.6.0",
-        "typescript": "^3.9.5",
-        "xo": "^0.32.0"
+        "@types/node": "^17.0.9",
+        "c8": "^7.11.0",
+        "typescript": "^4.5.4"
     },
-    "xo": {
-        "overrides": [
-            {
-                "files": "test.js",
-                "rules": {
-                    "node/no-unsupported-features/es-syntax": 0,
-                    "node/no-unsupported-features/node-builtins": 0
-                }
-            }
-        ]
-    },
-    "peerDependencies": {
-        "domexception": "^2.0.1"
+    "funding": [
+        {
+            "type": "github",
+            "url": "https://github.com/sponsors/jimmywarting"
+        },
+        {
+            "type": "paypal",
+            "url": "https://paypal.me/jimmywarting"
+        }
+    ],
+    "dependencies": {
+        "node-domexception": "^1.0.0",
+        "web-streams-polyfill": "^3.0.3"
     }
 }

streams.cjs

@@ -0,0 +1,51 @@
+/* c8 ignore start */
+// 64 KiB (same size chrome slice theirs blob into Uint8array's)
+const POOL_SIZE = 65536
+
+if (!globalThis.ReadableStream) {
+  // `node:stream/web` got introduced in v16.5.0 as experimental
+  // and it's preferred over the polyfilled version. So we also
+  // suppress the warning that gets emitted by NodeJS for using it.
+  try {
+    const process = require('node:process')
+    const { emitWarning } = process
+    try {
+      process.emitWarning = () => {}
+      Object.assign(globalThis, require('node:stream/web'))
+      process.emitWarning = emitWarning
+    } catch (error) {
+      process.emitWarning = emitWarning
+      throw error
+    }
+  } catch (error) {
+    // fallback to polyfill implementation
+    Object.assign(globalThis, require('web-streams-polyfill/dist/ponyfill.es2018.js'))
+  }
+}
+
+try {
+  // Don't use node: prefix for this, require+node: is not supported until node v14.14
+  // Only `import()` can use prefix in 12.20 and later
+  const { Blob } = require('buffer')
+  if (Blob && !Blob.prototype.stream) {
+    Blob.prototype.stream = function name (params) {
+      let position = 0
+      const blob = this
+
+      return new ReadableStream({
+        type: 'bytes',
+        async pull (ctrl) {
+          const chunk = blob.slice(position, Math.min(blob.size, position + POOL_SIZE))
+          const buffer = await chunk.arrayBuffer()
+          position += buffer.byteLength
+          ctrl.enqueue(new Uint8Array(buffer))
+
+          if (position === blob.size) {
+            ctrl.close()
+          }
+        }
+      })
+    }
+  }
+} catch (error) {}
+/* c8 ignore end */

test.js

@@ -1,162 +0,0 @@
-const fs = require('fs');
-const test = require('ava');
-const Blob = require('.');
-const blobFrom = require('./from');
-const getStream = require('get-stream');
-const {Response} = require('node-fetch');
-const {TextDecoder} = require('util');
-
-test('new Blob()', t => {
-	const blob = new Blob(); // eslint-disable-line no-unused-vars
-	t.pass();
-});
-
-test('new Blob(parts)', t => {
-	const data = 'a=1';
-	const blob = new Blob([data]); // eslint-disable-line no-unused-vars
-	t.pass();
-});
-
-test('Blob ctor parts', async t => {
-	const parts = [
-		'a',
-		new Uint8Array([98]),
-		new Uint16Array([25699]),
-		new Uint8Array([101]).buffer,
-		Buffer.from('f'),
-		new Blob(['g']),
-		{}
-	];
-
-	const blob = new Blob(parts);
-	t.is(await blob.text(), 'abcdefg[object Object]');
-});
-
-test('Blob size', t => {
-	const data = 'a=1';
-	const blob = new Blob([data]);
-	t.is(blob.size, data.length);
-});
-
-test('Blob type', t => {
-	const type = 'text/plain';
-	const blob = new Blob([], {type});
-	t.is(blob.type, type);
-});
-
-test('Blob slice type', t => {
-	const type = 'text/plain';
-	const blob = new Blob().slice(0, 0, type);
-	t.is(blob.type, type);
-});
-
-test('invalid Blob type', t => {
-	const blob = new Blob([], {type: '\u001Ftext/plain'});
-	t.is(blob.type, '');
-});
-
-test('invalid Blob slice type', t => {
-	const blob = new Blob().slice(0, 0, '\u001Ftext/plain');
-	t.is(blob.type, '');
-});
-
-test('Blob text()', async t => {
-	const data = 'a=1';
-	const type = 'text/plain';
-	const blob = new Blob([data], {type});
-	t.is(await blob.text(), data);
-});
-
-test('Blob arrayBuffer()', async t => {
-	const data = 'a=1';
-	const type = 'text/plain';
-	const blob = new Blob([data], {type});
-
-	const decoder = new TextDecoder('utf-8');
-	const buffer = await blob.arrayBuffer();
-	t.is(decoder.decode(buffer), data);
-});
-
-test('Blob stream()', async t => {
-	const data = 'a=1';
-	const type = 'text/plain';
-	const blob = new Blob([data], {type});
-	const result = await getStream(blob.stream());
-	t.is(result, data);
-});
-
-test('Blob toString()', t => {
-	const data = 'a=1';
-	const type = 'text/plain';
-	const blob = new Blob([data], {type});
-	t.is(blob.toString(), '[object Blob]');
-});
-
-test('Blob slice()', async t => {
-	const data = 'abcdefgh';
-	const blob = new Blob([data]).slice();
-	t.is(await blob.text(), data);
-});
-
-test('Blob slice(0, 1)', async t => {
-	const data = 'abcdefgh';
-	const blob = new Blob([data]).slice(0, 1);
-	t.is(await blob.text(), 'a');
-});
-
-test('Blob slice(-1)', async t => {
-	const data = 'abcdefgh';
-	const blob = new Blob([data]).slice(-1);
-	t.is(await blob.text(), 'h');
-});
-
-test('Blob slice(0, -1)', async t => {
-	const data = 'abcdefgh';
-	const blob = new Blob([data]).slice(0, -1);
-	t.is(await blob.text(), 'abcdefg');
-});
-
-test('Blob(["hello ", "world"]).slice(5)', async t => {
-	const parts = ['hello ', 'world'];
-	const blob = new Blob(parts);
-	t.is(await blob.slice(5).text(), ' world');
-});
-
-test('throw away unwanted parts', async t => {
-	const blob = new Blob(['a', 'b', 'c']).slice(1, 2);
-	t.is(await blob.text(), 'b');
-});
-
-test('Blob works with node-fetch Response.blob()', async t => {
-	const data = 'a=1';
-	const type = 'text/plain';
-	const blob = new Blob([data], {type});
-	const response = new Response(blob);
-	const blob2 = await response.blob();
-	t.is(await blob2.text(), data);
-});
-
-test('Blob works with node-fetch Response.text()', async t => {
-	const data = 'a=1';
-	const type = 'text/plain';
-	const blob = new Blob([data], {type});
-	const response = new Response(blob);
-	const text = await response.text();
-	t.is(text, data);
-});
-
-test('blob part backed up by filesystem', async t => {
-	const blob = blobFrom('./LICENSE');
-	t.is(await blob.slice(0, 3).text(), 'MIT');
-	t.is(await blob.slice(4, 11).text(), 'License');
-});
-
-test('Reading after modified should fail', async t => {
-	const blob = blobFrom('./LICENSE');
-	await new Promise(resolve => setTimeout(resolve, 100));
-	const now = new Date();
-	// Change modified time
-	fs.utimesSync('./LICENSE', now, now);
-	const error = await blob.text().catch(error => error);
-	t.is(error.name, 'NotReadableError');
-});

test/http-loader.js

@@ -0,0 +1,65 @@
+import { Buffer } from 'node:buffer'
+import fs from 'node:fs'
+import { get } from 'node:https'
+
+const fetch = url => new Promise(rs => get(url, rs))
+const cache = new URL('./.cache/', import.meta.url)
+
+/**
+ * @param {string} specifier
+ * @param {{
+ *   conditions: !Array<string>,
+ *   parentURL: !(string | undefined),
+ * }} context
+ * @param {Function} defaultResolve
+ * @returns {Promise<{ url: string }>}
+ */
+export async function resolve (specifier, context, defaultResolve) {
+  const { parentURL = null } = context
+
+  // Normally Node.js would error on specifiers starting with 'https://', so
+  // this hook intercepts them and converts them into absolute URLs to be
+  // passed along to the later hooks below.
+  if (specifier.startsWith('https://')) {
+    return {
+      url: specifier
+    }
+  } else if (parentURL && parentURL.startsWith('https://')) {
+    return {
+      url: new URL(specifier, parentURL).href
+    }
+  }
+
+  // Let Node.js handle all other specifiers.
+  return defaultResolve(specifier, context, defaultResolve)
+}
+
+export async function load (url, context, defaultLoad) {
+  // For JavaScript to be loaded over the network, we need to fetch and
+  // return it.
+  if (url.startsWith('https://')) {
+    const uuid = Buffer.from(url).toString('hex')
+    const cachedFile = new URL(uuid, cache)
+    let data = ''
+
+    // cache remote files for 1h
+    if (fs.existsSync(cachedFile) && fs.statSync(cachedFile).mtimeMs > Date.now() - 1000 * 60 * 60) {
+      data = fs.readFileSync(cachedFile, 'utf8')
+    } else {
+      const res = await fetch(url).catch(err => err)
+      for await (const chunk of res) data += chunk
+      fs.mkdirSync(cache, { recursive: true })
+      fs.writeFileSync(cachedFile, data)
+    }
+
+    return {
+      // This example assumes all network-provided JavaScript is ES module
+      // code.
+      format: 'module',
+      source: data
+    }
+  }
+
+  // Let Node.js handle all other URLs.
+  return defaultLoad(url, context, defaultLoad)
+}

test/own-misc-test.js

@@ -0,0 +1,223 @@
+// @ts-nocheck
+// @ts-ignore
+
+import fs from 'node:fs'
+import buffer from 'node:buffer'
+import syncBlob, { blobFromSync, blobFrom, fileFromSync, fileFrom } from '../from.js'
+
+const license = fs.readFileSync('./LICENSE')
+
+test_blob(() => new Blob([
+  'a',
+  new Uint8Array([98]),
+  new Uint16Array([25699]),
+  new Uint8Array([101]).buffer,
+  Buffer.from('f'),
+  new Blob(['g']),
+  {},
+  new URLSearchParams('foo')
+]), {
+  desc: 'Blob ctor parts',
+  expected: 'abcdefg[object Object]foo=',
+  type: '',
+  length: 26
+})
+
+promise_test(async () => {
+  assert_equals(fileFromSync('./LICENSE').name, 'LICENSE')
+  assert_equals((await fileFrom('./LICENSE')).name, 'LICENSE')
+}, 'file from returns the same name')
+
+// Could not find similar test on WPT
+test(() => {
+  const now = new Date()
+  assert_equals(new File([], '', { lastModified: now }).lastModified, +now)
+  assert_equals(new File([], '', { lastModified: +now }).lastModified, +now)
+  assert_equals(new File([], '', { lastModified: 100 }).lastModified, 100)
+  assert_equals(new File([], '', { lastModified: '200' }).lastModified, 200)
+  assert_equals(new File([], '', { lastModified: true }).lastModified, 1)
+  assert_equals(new File([], '', { lastModified: false }).lastModified, 0)
+  assert_approx_equals(new File([], '').lastModified, Date.now(), 0.020)
+  assert_approx_equals(new File([], '', { lastModified: undefined }).lastModified, Date.now(), 0.020)
+}, 'File sets current time')
+
+// Could not find similar test on WPT
+test(() => {
+  const values = ['Not a Number', [], {}, null]
+  // I can't really see anything about this in the spec,
+  // but this is how browsers handle type casting for this option...
+  for (const lastModified of values) {
+    const file = new File([], '', { lastModified })
+    assert_equals(file.lastModified, 0)
+  }
+}, 'Interpretes NaN value in lastModified option as 0')
+
+test(() => {
+  assert_equals(blobFromSync, syncBlob)
+}, 'default export is named exported blobFromSync')
+
+promise_test(async () => {
+  const { Blob, default: def } = await import('../index.js')
+  assert_equals(Blob, def)
+}, 'Can use named import - as well as default')
+
+// This was necessary to avoid large ArrayBuffer clones (slice)
+promise_test(async t => {
+  const buf = new Uint8Array(65590)
+  const blob = new Blob([buf])
+  let i = 0
+  // eslint-disable-next-line no-unused-vars
+  for await (const chunk of blob.stream()) {
+    i++
+  }
+
+  assert_equals(i, 2)
+}, 'Large chunks are divided into smaller chunks')
+
+// Couldn't find a test for this on WPT
+promise_test(async () => {
+  const buf = new Uint8Array([97])
+  const blob = new Blob([buf])
+  const chunk = await blob.stream().getReader().read()
+  assert_equals(chunk.value[0], 97)
+  chunk.value[0] = 98
+  assert_equals(await blob.text(), 'a')
+}, 'Blobs are immutable')
+
+/**
+ * Deviation from WPT: it's important to keep boundary value
+ * so we don't lowercase the type
+ * @see https://github.com/w3c/FileAPI/issues/43
+ */
+test(() => {
+  const type = 'multipart/form-data; boundary=----WebKitFormBoundaryTKqdrVt01qOBltBd'
+  assert_equals(new Blob([], { type }).type, type)
+  assert_equals(new File([], '', { type }).type, type)
+}, 'Dose not lowercase the type')
+
+
+test( // Because we have symbol.hasInstance it's best to test it...
+  () => (assert_false(null instanceof Blob), assert_false(null instanceof File)),
+ 'Instanceof check returns false for nullish values'
+)
+
+test( // Because browser normally never tries things taken for granted
+  () => assert_equals(new Blob().toString(), '[object Blob]'),
+  'blob.toString() returns [object Blob]'
+)
+
+test( // Because browser normally never tries things taken for granted
+  () => assert_equals(new File([], '').toString(), '[object File]'),
+  'file.toString() returns [object File]'
+)
+
+// fetch-blob uniques is that it supports arbitrary blobs too
+test(() => {
+  class File {
+    stream () {}
+    get [Symbol.toStringTag] () { return 'File' }
+  }
+  assert_true(new File() instanceof Blob)
+}, 'Blob-ish class is an instance of Blob')
+
+// fetch-blob uniques is that it supports arbitrary blobs too
+if (buffer.Blob) {
+  test_blob(() => new Blob([new buffer.Blob(['blob part'])]), {
+    desc: 'Can wrap buffer.Blob to a fetch-blob',
+    expected: 'blob part',
+    type: '',
+  })
+}
+
+/**
+ * Test if Blob can be constructed with BOM and keep it when casted to string
+ * Test if blob.text() can correctly remove BOM - `buffer.toString()` is bad
+ */
+promise_test(async () => {
+  const text = '{"foo": "bar"}'
+  const blob = new Blob([`\uFEFF${text}`])
+  assert_equals(blob.size, 17)
+  assert_equals(await blob.text(), text)
+  const ab = await blob.slice(0, 3).arrayBuffer()
+  assert_equals_typed_array(new Uint8Array(ab), new Uint8Array([0xEF, 0xBB, 0xBF]))
+}, 'Can wrap buffer.Blob to a fetch-blob')
+
+// Here to make sure our `toIterator` is working as intended
+promise_test(async () => {
+  const stream = new Blob(['Some content']).stream()
+
+  // Cancel the stream before start reading, or this will throw an error
+  await stream.cancel()
+  const reader = stream.getReader()
+  const { done, value: chunk } = await reader.read()
+
+  assert_true(done)
+  assert_equals(chunk, undefined)
+}, 'Blob stream() can be cancelled')
+
+/******************************************************************************/
+/*                                                                            */
+/*                   Test Blobs backed up by the filesystem                   */
+/*                                                                            */
+/******************************************************************************/
+
+promise_test(async () => {
+  assert_equals(fileFromSync('./LICENSE', 'text/plain').type, 'text/plain')
+  assert_equals(fileFromSync('./LICENSE').type, '')
+
+  assert_equals(blobFromSync('./LICENSE', 'text/plain').type, 'text/plain')
+  assert_equals(blobFromSync('./LICENSE').type, '')
+
+  assert_equals((await fileFrom('./LICENSE', 'text/plain')).type, 'text/plain')
+  assert_equals((await fileFrom('./LICENSE')).type, '')
+
+  assert_equals((await blobFrom('./LICENSE', 'text/plain')).type, 'text/plain')
+  assert_equals((await blobFrom('./LICENSE')).type, '')
+}, 'from utilities sets correct type')
+
+promise_test(async () => {
+  assert_equals(await blobFromSync('./LICENSE').text(), license.toString())
+  assert_equals(await fileFromSync('./LICENSE').text(), license.toString())
+  assert_equals(await (await blobFrom('./LICENSE')).text(), license.toString())
+  assert_equals(await (await fileFrom('./LICENSE')).text(), license.toString())
+}, 'blob part backed up by filesystem can be read')
+
+promise_test(async () => {
+  assert_equals(await blobFromSync('./LICENSE').text(), license.toString())
+  assert_equals(await fileFromSync('./LICENSE').text(), license.toString())
+  assert_equals(await (await blobFrom('./LICENSE')).text(), license.toString())
+  assert_equals(await (await fileFrom('./LICENSE')).text(), license.toString())
+}, 'blob part backed up by filesystem slice correctly')
+
+promise_test(async () => {
+  fs.writeFileSync('temp', '')
+  await blobFromSync('./temp').text()
+  fs.unlinkSync('./temp')
+}, 'can read empty files')
+
+test(async () => {
+  const blob = blobFromSync('./LICENSE')
+  await new Promise(resolve => setTimeout(resolve, 2000))
+  const now = new Date()
+  // Change modified time
+  fs.utimesSync('./LICENSE', now, now)
+  const error = await blob.text().then(assert_unreached, e => e)
+  assert_equals(error.constructor.name, 'DOMException')
+  assert_equals(error instanceof Error, true)
+  assert_equals(error.name, 'NotReadableError')
+
+  const file = fileFromSync('./LICENSE')
+  // Above test updates the last modified date to now
+  assert_equals(typeof file.lastModified, 'number')
+  // The lastModifiedDate is deprecated and removed from spec
+  assert_false('lastModifiedDate' in file)
+  assert_approx_equals(file.lastModified, +now, 1000)
+}, 'Reading after modified should fail')
+
+promise_test(async () => {
+  assert_equals(await blobFromSync('./LICENSE').slice(0, 0).text(), '')
+  assert_equals(await blobFromSync('./LICENSE').slice(0, 3).text(), license.slice(0, 3).toString())
+  assert_equals(await blobFromSync('./LICENSE').slice(4, 11).text(), license.slice(4, 11).toString())
+  assert_equals(await blobFromSync('./LICENSE').slice(-11).text(), license.slice(-11).toString())
+  assert_equals(await blobFromSync('./LICENSE').slice(4, 11).slice(2, 5).text(), license.slice(4, 11).slice(2, 5).toString())
+}, 'slicing blobs backed up by filesystem returns correct string')

test/test-wpt-in-node.js

@@ -0,0 +1,143 @@
+// Don't want to use the FileReader, don't want to lowerCase the type either
+// import from 'https://wpt.live/resources/testharnessreport.js'
+import { File, Blob } from '../from.js'
+
+let hasFailed
+globalThis.self = globalThis
+await import('https://wpt.live/resources/testharness.js')
+
+setup({
+  explicit_timeout: true,
+  explicit_done: true
+})
+
+function test_blob (fn, expectations) {
+  const expected = expectations.expected
+  const type = expectations.type
+  const desc = expectations.desc
+  const length = expectations.length
+
+  const t = async_test(desc)
+  t.step(async function () {
+    const blob = fn()
+    assert_true(blob instanceof Blob)
+    assert_false(blob instanceof File)
+    assert_equals(blob.type.toLowerCase(), type)
+    assert_equals(await blob.text(), expected)
+    t.done()
+  })
+}
+
+function test_blob_binary (fn, expectations) {
+  const expected = expectations.expected
+  const type = expectations.type
+  const desc = expectations.desc
+
+  const t = async_test(desc)
+  t.step(async function () {
+    const blob = fn()
+    assert_true(blob instanceof Blob)
+    assert_false(blob instanceof File)
+    assert_equals(blob.type.toLowerCase(), type)
+    const result = await blob.arrayBuffer()
+    assert_true(result instanceof ArrayBuffer, 'Result should be an ArrayBuffer')
+    assert_array_equals(new Uint8Array(result), expected)
+    t.done()
+  })
+}
+
+// Assert that two TypedArray objects have the same byte values
+globalThis.assert_equals_typed_array = (array1, array2) => {
+  const [view1, view2] = [array1, array2].map((array) => {
+    assert_true(array.buffer instanceof ArrayBuffer,
+      'Expect input ArrayBuffers to contain field `buffer`')
+    return new DataView(array.buffer, array.byteOffset, array.byteLength)
+  })
+
+  assert_equals(view1.byteLength, view2.byteLength,
+    'Expect both arrays to be of the same byte length')
+
+  const byteLength = view1.byteLength
+
+  for (let i = 0; i < byteLength; ++i) {
+    assert_equals(view1.getUint8(i), view2.getUint8(i),
+      `Expect byte at buffer position ${i} to be equal`)
+  }
+}
+
+globalThis.add_result_callback((test, ...args) => {
+  if ([
+    'Blob with type "A"',
+    'Blob with type "TEXT/HTML"',
+    'Getters and value conversions should happen in order until an exception is thrown.',
+    'Using type in File constructor: TEXT/PLAIN',
+    'Using type in File constructor: text/plain;charset=UTF-8'
+  ].includes(test.name)) return
+
+  const INDENT_SIZE = 2
+  const reporter = {}
+
+  reporter.startSuite = name => console.log(`\n  ${(name)}\n`)
+
+  reporter.pass = message => console.log((indent(('√ ') + message, INDENT_SIZE)))
+
+  reporter.fail = message => console.log((indent('\u00D7 ' + message, INDENT_SIZE)))
+
+  reporter.reportStack = stack => console.log((indent(stack, INDENT_SIZE * 2)))
+
+  function indent (string, times) {
+    const prefix = ' '.repeat(times)
+    return string.split('\n').map(l => prefix + l).join('\n')
+  }
+
+  if (test.status === 0) {
+    reporter.pass(test.name)
+  } else if (test.status === 1) {
+    reporter.fail(`${test.name}\n`)
+    reporter.reportStack(`${test.message}\n${test.stack}`)
+    hasFailed = true
+  } else if (test.status === 2) {
+    reporter.fail(`${test.name} (timeout)\n`)
+    reporter.reportStack(`${test.message}\n${test.stack}`)
+    hasFailed = true
+  } else if (test.status === 3) {
+    reporter.fail(`${test.name} (incomplete)\n`)
+    reporter.reportStack(`${test.message}\n${test.stack}`)
+    hasFailed = true
+  } else if (test.status === 4) {
+    reporter.fail(`${test.name} (precondition failed)\n`)
+    reporter.reportStack(`${test.message}\n${test.stack}`)
+    hasFailed = true
+  } else {
+    reporter.fail(`unknown test status: ${test.status}`)
+    hasFailed = true
+  }
+})
+
+globalThis.File = File
+globalThis.Blob = Blob
+globalThis.garbageCollect = () => {}
+globalThis.test_blob = test_blob
+globalThis.test_blob_binary = test_blob_binary
+// Cuz WPT don't clean up after itself
+globalThis.MessageChannel = class extends MessageChannel {
+  constructor () {
+    super()
+    setTimeout(() => {
+      this.port1.close()
+      this.port2.close()
+      this.port1.onmessage = this.port2.onmessage = null
+    }, 100)
+  }
+}
+
+import('https://wpt.live/FileAPI/file/File-constructor.any.js')
+import('https://wpt.live/FileAPI/blob/Blob-constructor.any.js')
+import('https://wpt.live/FileAPI/blob/Blob-array-buffer.any.js')
+import('https://wpt.live/FileAPI/blob/Blob-slice-overflow.any.js')
+import('https://wpt.live/FileAPI/blob/Blob-slice.any.js')
+import('https://wpt.live/FileAPI/blob/Blob-stream.any.js')
+import('https://wpt.live/FileAPI/blob/Blob-text.any.js')
+import('./own-misc-test.js')
+
+hasFailed && process.exit(1)