Bump c8 from 7.14.0 to 8.0.1

Bumps [c8](https://github.com/bcoe/c8) from 7.14.0 to 8.0.1.
- [Release notes](https://github.com/bcoe/c8/releases)
- [Changelog](https://github.com/bcoe/c8/blob/main/CHANGELOG.md)
- [Commits](https://github.com/bcoe/c8/compare/v7.14.0...v8.0.1)

---
updated-dependencies:
- dependency-name: c8
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -12,9 +12,8 @@
 
 -------------------------------------------------------------------------------------------------
 
-<!-- Mark what you have done, Remove unnecessary ones. Add new tasks that may fit (like TODO's) -->
+<!-- Mark what you have done with [x], 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)
 

.github/workflows/ci.yml

@@ -13,8 +13,8 @@ jobs:
   test:
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macOS-latest]
-        node: ["17.3"]
+        os: [ubuntu-latest]
+        node: ["16", "18", "20"]
 
     runs-on: ${{ matrix.os }}
 
@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: '17.3'
+          node-version: ${{ matrix.node }}
       - run: npm install
       - run: npm test
       - run: npm run report -- --colors

CHANGELOG.md

@@ -1,98 +0,0 @@
-# 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).
-- Added blob backed up by filesystem (#55)
-
-## v2.0.1
-
-- Fix: remove upper bound for node engine semver (#49).
-
-## v2.0.0
-
-> Note: This release was previously published as `1.0.7`, but as it contains breaking changes, we renamed it to `2.0.0`.
-
-- **Breaking:** minimum supported Node.js version is now 10.17.
-- **Breaking:** `buffer` option has been removed.
-- Enhance: create TypeScript declarations from JSDoc (#45).
-- Enhance: operate on blob parts (byte sequence) (#44).
-- Enhance: use a `WeakMap` for private properties (#42) .
-- Other: update formatting.
-
-## v1.0.6
-
-- Enhance: use upstream Blob directly in typings (#38)
-- Other: update dependencies
-
-## v1.0.5
-
-- Other: no change to code, update dev dependency to address vulnerability reports
-
-## v1.0.4
-
-- Other: general code rewrite to pass linting, prepare for `node-fetch` release v3
-
-## v1.0.3
-
-- Fix: package.json export `blob.js` properly now
-
-## v1.0.2
-
-- Other: fix test integration
-
-## v1.0.1
-
-- Other: readme update
-
-## 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

@@ -7,6 +7,8 @@
 
 A Blob implementation in Node.js, originally from [node-fetch](https://github.com/node-fetch/node-fetch).
 
+Use the built-in [`Blob`](https://nodejs.org/docs/latest-v18.x/api/buffer.html#class-blob) in Node.js 18 and later.
+
 ## Installation
 
 ```sh
@@ -24,7 +26,6 @@ npm install fetch-blob
     - 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>
@@ -46,14 +47,10 @@ npm install fetch-blob
 
 ```js
 // 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'
+import { Blob } from 'fetch-blob'
+import { File } from 'fetch-blob/file.js'
 
-import {Blob} from 'fetch-blob'
-import {File} from 'fetch-blob/file.js'
-
-const {Blob} = await import('fetch-blob')
+const { Blob } = await import('fetch-blob')
 
 
 // Ways to read the blob:
@@ -73,7 +70,6 @@ It will not read the content into memory. It will only stat the file for last mo
 
 ```js
 // 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'
 
 const fsFile = fileFromSync('./2-GiB-file.bin', 'application/octet-stream')
@@ -87,9 +83,38 @@ console.log(blob.size) // ~4 GiB
 
 `blobFrom|blobFromSync|fileFrom|fileFromSync(path, [mimetype])`
 
+### Creating a temporary file on the disk
+(requires [FinalizationRegistry] - node v14.6)
+
+When using both `createTemporaryBlob` and `createTemporaryFile`
+then you will write data to the temporary folder in their respective OS.
+The arguments can be anything that [fsPromises.writeFile] supports. NodeJS
+v14.17.0+ also supports writing (async)Iterable streams and passing in a
+AbortSignal, so both NodeJS stream and whatwg streams are supported. When the
+file have been written it will return a Blob/File handle with a references to
+this temporary location on the disk. When you no longer have a references to
+this Blob/File anymore and it have been GC then it will automatically be deleted.
+
+This files are also unlinked upon exiting the process.
+```js
+import { createTemporaryBlob, createTemporaryFile } from 'fetch-blob/from.js'
+
+const req = new Request('https://httpbin.org/image/png')
+const res = await fetch(req)
+const type = res.headers.get('content-type')
+const signal = req.signal
+let blob = await createTemporaryBlob(res.body, { type, signal })
+// const file = createTemporaryBlob(res.body, 'img.png', { type, signal })
+blob = undefined // loosing references will delete the file from disk
+```
+
+- `createTemporaryBlob(data, { type, signal })`
+- `createTemporaryFile(data, FileName, { type, signal, lastModified })`
+
 ### 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 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()`, `stream()` methods (the stream method
+can be as simple as being a sync or async iterator that yields Uint8Arrays. 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 (aka: text(), arrayBuffer() and type and a ReadableStream)
 
 An example of this could be to create a file or blob like item coming from a remote HTTP request. Or from a DataBase
 
@@ -104,3 +129,5 @@ See the [MDN documentation](https://developer.mozilla.org/en-US/docs/Web/API/Blo
 [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
+[fsPromises.writeFile]: https://nodejs.org/dist/latest-v18.x/docs/api/fs.html#fspromiseswritefilefile-data-options
+[FinalizationRegistry]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry

file.js

@@ -1,4 +1,4 @@
-import Blob from './index.js'
+import { Blob } from './index.js'
 
 const _File = class File extends Blob {
   #lastModified = 0
@@ -46,4 +46,3 @@ const _File = class File extends Blob {
 
 /** @type {typeof globalThis.File} */// @ts-ignore
 export const File = _File
-export default File

from.js

@@ -1,11 +1,20 @@
-import { statSync, createReadStream, promises as fs } from 'node:fs'
-import { basename } from 'node:path'
+import {
+  realpathSync,
+  statSync,
+  rmdirSync,
+  createReadStream,
+  promises as fs
+} from 'node:fs'
+import { basename, sep, join } from 'node:path'
+import { tmpdir } from 'node:os'
+import process from 'node:process'
 import DOMException from 'node-domexception'
 
-import File from './file.js'
-import Blob from './index.js'
+import { File } from './file.js'
+import { Blob } from './index.js'
 
-const { stat } = fs
+const { stat, mkdtemp } = fs
+let i = 0, tempDir, registry
 
 /**
  * @param {string} path filepath on the disk
@@ -49,6 +58,42 @@ const fromFile = (stat, path, type = '') => new File([new BlobDataItem({
   start: 0
 })], basename(path), { type, lastModified: stat.mtimeMs })
 
+/**
+ * Creates a temporary blob backed by the filesystem.
+ * NOTE: requires node.js v14 or higher to use FinalizationRegistry
+ *
+ * @param {*} data Same as fs.writeFile data
+ * @param {BlobPropertyBag & {signal?: AbortSignal}} options
+ * @param {AbortSignal} [signal] in case you wish to cancel the write operation
+ * @returns {Promise<Blob>}
+ */
+const createTemporaryBlob = async (data, {signal, type} = {}) => {
+  registry = registry || new FinalizationRegistry(fs.unlink)
+  tempDir = tempDir || await mkdtemp(realpathSync(tmpdir()) + sep)
+  const id = `${i++}`
+  const destination = join(tempDir, id)
+  if (data instanceof ArrayBuffer) data = new Uint8Array(data)
+  await fs.writeFile(destination, data, { signal })
+  const blob = await blobFrom(destination, type)
+  registry.register(blob, destination)
+  return blob
+}
+
+/**
+ * Creates a temporary File backed by the filesystem.
+ * Pretty much the same as constructing a new File(data, name, options)
+ *
+ * NOTE: requires node.js v14 or higher to use FinalizationRegistry
+ * @param {*} data
+ * @param {string} name
+ * @param {FilePropertyBag & {signal?: AbortSignal}} opts
+ * @returns {Promise<File>}
+ */
+const createTemporaryFile = async (data, name, opts) => {
+  const blob = await createTemporaryBlob(data)
+  return new File([blob], name, opts)
+}
+
 /**
  * This is a blob backed up by a file on the disk
  * with minium requirement. Its wrapped around a Blob as a blobPart
@@ -65,6 +110,9 @@ class BlobDataItem {
     this.#start = options.start
     this.size = options.size
     this.lastModified = options.lastModified
+    this.originalSize = options.originalSize === undefined
+      ? options.size
+      : options.originalSize
   }
 
   /**
@@ -75,16 +123,19 @@ class BlobDataItem {
     return new BlobDataItem({
       path: this.#path,
       lastModified: this.lastModified,
+      originalSize: this.originalSize,
       size: end - start,
       start: this.#start + start
     })
   }
 
   async * stream () {
-    const { mtimeMs } = await stat(this.#path)
-    if (mtimeMs > this.lastModified) {
+    const { mtimeMs, size } = await stat(this.#path)
+
+    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
@@ -96,5 +147,18 @@ class BlobDataItem {
   }
 }
 
+process.once('exit', () => {
+  tempDir && rmdirSync(tempDir, { recursive: true })
+})
+
 export default blobFromSync
-export { File, Blob, blobFrom, blobFromSync, fileFrom, fileFromSync }
+export {
+  Blob,
+  blobFrom,
+  blobFromSync,
+  createTemporaryBlob,
+  File,
+  fileFrom,
+  fileFromSync,
+  createTemporaryFile
+}

index.js

@@ -1,19 +1,32 @@
 /*! fetch-blob. MIT License. Jimmy Wärting <https://jimmy.warting.se/opensource> */
 
-// TODO (jimmywarting): in the feature use conditional loading with top level await (requires 14.x)
-// Node has recently added whatwg stream into core
-
-import './streams.cjs'
+if (!globalThis.ReadableStream) {
+  try {
+    const process = await import('node:process').then(m => m.default)
+    const { emitWarning } = process
+    try {
+      process.emitWarning = () => {}
+      const streams = await import('node:stream/web').then(m => m.default)
+      Object.assign(globalThis, streams)
+      process.emitWarning = emitWarning
+    } catch (error) {
+      process.emitWarning = emitWarning
+      throw error
+    }
+  } catch (error) {}
+}
 
 // 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) {
+/**
+ * @param {(Blob | Uint8Array)[]} parts
+ * @param {boolean} clone
+ * @returns {AsyncIterableIterator<Uint8Array>}
+ */
+async function * toIterator (parts, clone) {
   for (const part of parts) {
-    if ('stream' in part) {
-      yield * (/** @type {AsyncIterableIterator<Uint8Array>} */ (part.stream()))
-    } else if (ArrayBuffer.isView(part)) {
+    if (ArrayBuffer.isView(part)) {
       if (clone) {
         let position = part.byteOffset
         const end = part.byteOffset + part.byteLength
@@ -26,16 +39,9 @@ async function * toIterator (parts, clone = true) {
       } 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)
-      }
+      // @ts-ignore TS Think blob.stream() returns a node:stream
+      yield * part.stream()
     }
   }
 }
@@ -83,8 +89,12 @@ const _Blob = class Blob {
         part = encoder.encode(`${element}`)
       }
 
-      this.#size += ArrayBuffer.isView(part) ? part.byteLength : part.size
-      this.#parts.push(part)
+      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)
+      }
     }
 
     this.#endings = `${options.endings === undefined ? 'transparent' : options.endings}`
@@ -135,11 +145,6 @@ const _Blob = class Blob {
    * @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;
-
     const data = new Uint8Array(this.size)
     let offset = 0
     for await (const chunk of toIterator(this.#parts, false)) {
@@ -214,7 +219,7 @@ const _Blob = class Blob {
       }
     }
 
-    const blob = new Blob([], { type: String(type).toLowerCase() })
+    const blob = new Blob([], { type: `${type}` })
     blob.#size = span
     blob.#parts = blobParts
 
@@ -247,4 +252,3 @@ Object.defineProperties(_Blob.prototype, {
 
 /** @type {typeof globalThis.Blob} */
 export const Blob = _Blob
-export default Blob

package.json

@@ -1,6 +1,6 @@
 {
     "name": "fetch-blob",
-    "version": "3.1.4",
+    "version": "4.0.0",
     "description": "Blob & File implementation in Node.js, originally from node-fetch.",
     "main": "index.js",
     "type": "module",
@@ -10,8 +10,7 @@
         "file.d.ts",
         "index.js",
         "index.d.ts",
-        "from.d.ts",
-        "streams.cjs"
+        "from.d.ts"
     ],
     "scripts": {
         "test": "node --experimental-loader ./test/http-loader.js ./test/test-wpt-in-node.js",
@@ -26,7 +25,7 @@
         "node-fetch"
     ],
     "engines": {
-        "node": "^12.20 || >= 14.13"
+        "node": ">=16.7"
     },
     "author": "Jimmy Wärting <jimmy@warting.se> (https://jimmy.warting.se)",
     "license": "MIT",
@@ -35,9 +34,9 @@
     },
     "homepage": "https://github.com/node-fetch/fetch-blob#readme",
     "devDependencies": {
-        "@types/node": "^17.0.9",
-        "c8": "^7.11.0",
-        "typescript": "^4.5.4"
+        "@types/node": "^16.5.0",
+        "c8": "^8.0.1",
+        "typescript": "^5.0.4"
     },
     "funding": [
         {
@@ -50,7 +49,6 @@
         }
     ],
     "dependencies": {
-        "node-domexception": "^1.0.0",
-        "web-streams-polyfill": "^3.0.3"
+        "node-domexception": "^1.0.0"
     }
 }

streams.cjs

@@ -1,51 +0,0 @@
-/* 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/http-loader.js

@@ -5,36 +5,29 @@ 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
+export function resolve(specifier, context, nextResolve) {
+  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
-    }
+      shortCircuit: true,
+      url: specifier,
+    };
   } else if (parentURL && parentURL.startsWith('https://')) {
     return {
-      url: new URL(specifier, parentURL).href
-    }
+      shortCircuit: true,
+      url: new URL(specifier, parentURL).href,
+    };
   }
 
   // Let Node.js handle all other specifiers.
-  return defaultResolve(specifier, context, defaultResolve)
+  return nextResolve(specifier);
 }
 
-export async function load (url, context, defaultLoad) {
+export async function load(url, context, nextLoad) {
   // For JavaScript to be loaded over the network, we need to fetch and
   // return it.
   if (url.startsWith('https://')) {
@@ -52,14 +45,15 @@ export async function load (url, context, defaultLoad) {
       fs.writeFileSync(cachedFile, data)
     }
 
+    // This example assumes all network-provided JavaScript is ES module
+    // code.
     return {
-      // This example assumes all network-provided JavaScript is ES module
-      // code.
       format: 'module',
-      source: data
+      shortCircuit: true,
+      source: data,
     }
   }
 
   // Let Node.js handle all other URLs.
-  return defaultLoad(url, context, defaultLoad)
-}
+  return nextLoad(url);
+}

test/own-misc-test.js

@@ -3,7 +3,14 @@
 
 import fs from 'node:fs'
 import buffer from 'node:buffer'
-import syncBlob, { blobFromSync, blobFrom, fileFromSync, fileFrom } from '../from.js'
+import syncBlob, {
+  blobFromSync,
+  blobFrom,
+  fileFromSync,
+  fileFrom,
+  createTemporaryBlob,
+  createTemporaryFile
+} from '../from.js'
 
 const license = fs.readFileSync('./LICENSE')
 
@@ -56,11 +63,6 @@ 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)
@@ -189,6 +191,44 @@ promise_test(async () => {
   assert_equals(await (await fileFrom('./LICENSE')).text(), license.toString())
 }, 'blob part backed up by filesystem slice correctly')
 
+promise_test(async () => {
+  let blob
+  // Can construct a temporary blob from a string
+  blob = await createTemporaryBlob(license.toString())
+  assert_equals(await blob.text(), license.toString())
+
+  // Can construct a temporary blob from a async iterator
+  blob = await createTemporaryBlob(blob.stream())
+  assert_equals(await blob.text(), license.toString())
+
+  // Can construct a temporary file from a arrayBuffer
+  blob = await createTemporaryBlob(await blob.arrayBuffer())
+  assert_equals(await blob.text(), license.toString())
+
+  // Can construct a temporary file from a arrayBufferView
+  blob = await createTemporaryBlob(await blob.arrayBuffer().then(ab => new Uint8Array(ab)))
+  assert_equals(await blob.text(), license.toString())
+
+  // Can specify a mime type
+  blob = await createTemporaryBlob('abc', { type: 'text/plain' })
+  assert_equals(blob.type, 'text/plain')
+
+  // Can create files too
+  let file = await createTemporaryFile('abc', 'abc.txt', {
+    type: 'text/plain',
+    lastModified: 123
+  })
+  assert_equals(file.name, 'abc.txt')
+  assert_equals(file.size, 3)
+  assert_equals(file.lastModified, 123)
+}, 'creating temporary blob/file backed up by filesystem')
+
+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))

test/test-wpt-in-node.js

@@ -22,7 +22,7 @@ function test_blob (fn, expectations) {
     const blob = fn()
     assert_true(blob instanceof Blob)
     assert_false(blob instanceof File)
-    assert_equals(blob.type.toLowerCase(), type)
+    assert_equals(blob.type.toLowerCase(), type.toLowerCase())
     assert_equals(await blob.text(), expected)
     t.done()
   })
@@ -140,4 +140,7 @@ 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)
+if (hasFailed) {
+  console.log('Tests failed')
+  process.exit(1)
+}