Expose TextEncoder for use in workers

lib/__tests__/cloudworker-e2e.test.js

@@ -274,4 +274,62 @@ describe('cloudworker-e2e', async () => {
     await server.close()
     cb()
   })
+
+  test('simple text encoder', async (cb) => {
+    const script = `
+      addEventListener('fetch', event => {
+        const encoder = new TextEncoder()
+        const { readable, writable } = new TransformStream()
+        const writer = writable.getWriter()
+        writer.write(encoder.encode('hello')).then(() => writer.close())
+        event.respondWith(new Response(readable, {status: 200}))
+      })
+    `
+    const server = new Cloudworker(script).listen(8080)
+    const res = await axios.get('http://localhost:8080', defaultAxiosOpts)
+    expect(res.status).toEqual(200)
+    expect(res.data).toEqual('hello')
+    await server.close()
+    cb()
+  })
+
+  test('simple text encoder and decoder', async (cb) => {
+    const script = `
+      addEventListener('fetch', event => {
+        const helloBytes = new Uint8Array([104, 101, 108, 108, 111])
+        const decoder = new TextDecoder()
+        const { readable, writable } = new TransformStream()
+        const writer = writable.getWriter()
+        writer.write(new TextEncoder().encode(decoder.decode(helloBytes))).then(() => writer.close())
+        event.respondWith(new Response(readable, {status: 200}))
+      })
+    `
+    const server = new Cloudworker(script).listen(8080)
+    const res = await axios.get('http://localhost:8080', defaultAxiosOpts)
+    expect(res.status).toEqual(200)
+    expect(res.data).toEqual('hello')
+    await server.close()
+    cb()
+  })
+
+  test('test ascii decoder can be specified', async (cb) => {
+    const script = `
+      addEventListener('fetch', event => {
+        const euroSymbol = new Uint8Array([226, 130, 172])
+        const decoder = new TextDecoder()
+        const asciiDecoder = new TextDecoder('ascii')
+        const sameDecodedValues = (decoder.decode(euroSymbol)) === (asciiDecoder.decode(euroSymbol))
+        const { readable, writable } = new TransformStream()
+        const writer = writable.getWriter()
+        writer.write(new TextEncoder().encode(sameDecodedValues)).then(() => writer.close())
+        event.respondWith(new Response(readable, {status: 200}))
+      })
+    `
+    const server = new Cloudworker(script).listen(8080)
+    const res = await axios.get('http://localhost:8080', defaultAxiosOpts)
+    expect(res.status).toEqual(200)
+    expect(res.data).toEqual(false)
+    await server.close()
+    cb()
+  })
 })

lib/runtime.js

@@ -2,6 +2,7 @@ const { Request, Response, fetch, Headers, freezeHeaders } = require('./runtime/
 const { URL } = require('./runtime/url')
 const { ReadableStream, WritableStream, TransformStream } = require('./runtime/stream')
 const { FetchEvent } = require('./runtime/fetch-event')
+const { TextDecoder, TextEncoder } = require('./runtime/text-encoder')
 const { atob, btoa } = require('./runtime/base64')
 
 class Context {
@@ -18,6 +19,8 @@ class Context {
     this.TransformStream = TransformStream
     this.FetchEvent = FetchEvent
     this.caches = cacheFactory
+    this.TextDecoder = TextDecoder
+    this.TextEncoder = TextEncoder
     this.atob = atob
     this.btoa = btoa
     Object.assign(this, bindings)

lib/runtime/__tests__/textencoder.test.js

@@ -0,0 +1,28 @@
+const textEncoding = require('../text-encoder.js')
+
+describe('text-encoder', () => {
+  test('able to fetch encoding from text decoder', () => {
+    const asciiDecoder = new textEncoding.TextDecoder('cp1251')
+    expect(asciiDecoder.encoding).toEqual('windows-1251')
+  })
+
+  test('able to obtain ignoreBom from text decoder', () => {
+    const asciiDecoder = new textEncoding.TextDecoder('ascii', { ignoreBOM: false })
+    expect(asciiDecoder.encoding).toEqual('windows-1252')
+    expect(asciiDecoder.ignoreBOM).toEqual(false)
+
+    const asciiDecoder2 = new textEncoding.TextDecoder('ascii', { ignoreBOM: true })
+    expect(asciiDecoder2.encoding).toEqual('windows-1252')
+    expect(asciiDecoder2.ignoreBOM).toEqual(true)
+  })
+
+  test('able to obtain fatal from text decoder', () => {
+    const asciiDecoder = new textEncoding.TextDecoder('ascii', { fatal: false })
+    expect(asciiDecoder.encoding).toEqual('windows-1252')
+    expect(asciiDecoder.fatal).toEqual(false)
+
+    const asciiDecoder2 = new textEncoding.TextDecoder('ascii', { fatal: true })
+    expect(asciiDecoder2.encoding).toEqual('windows-1252')
+    expect(asciiDecoder2.fatal).toEqual(true)
+  })
+})

lib/runtime/text-encoder.js

@@ -0,0 +1,40 @@
+const textEncoding = require('text-encoding')
+
+function CustomTextDecoder (label, options) {
+  if (!(this instanceof CustomTextDecoder)) {
+    throw TypeError('Called as a function. Did you forget \'new\'?')
+  }
+  this.decoder = new textEncoding.TextDecoder(label, options)
+  return this
+}
+
+CustomTextDecoder.prototype.decode = function decode (input, options) {
+  if (Object.prototype.toString.call(input) === '[object Uint8Array]') {
+    const buffer = new ArrayBuffer(input.length)
+    const view = new Uint8Array(buffer)
+    view.set(input)
+    return this.decoder.decode(
+      view,
+      options)
+  }
+
+  return this.decoder.decode(input, options)
+}
+
+Object.defineProperty(CustomTextDecoder.prototype, 'encoding', {
+  /** @this {CustomTextDecoder} */
+  get: function () { return this.decoder.encoding },
+})
+
+Object.defineProperty(CustomTextDecoder.prototype, 'fatal', {
+  /** @this {CustomTextDecoder} */
+  get: function () { return this.decoder.fatal },
+})
+
+Object.defineProperty(CustomTextDecoder.prototype, 'ignoreBOM', {
+  /** @this {CustomTextDecoder} */
+  get: function () { return this.decoder.ignoreBOM },
+})
+
+module.exports.TextDecoder = CustomTextDecoder
+module.exports.TextEncoder = textEncoding.TextEncoder