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GeezerVison is showing github.com — buffer: implement blob.textStream() · nodejs/node@55f4844

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  • doc/api
    • buffer.md
  • lib/internal
    • blob.js
  • test/parallel
    • test-blob.js
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‎doc/api/buffer.md‎

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+14Lines changed: 14 additions & 0 deletions
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@@ -593,6 +593,18 @@ added:
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Returns a promise that fulfills with the contents of the `Blob` decoded as a
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UTF-8 string.
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### `blob.textStream()`
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<!-- YAML
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added: REPLACEME
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-->
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* Returns: {ReadableStream}
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Returns a new `ReadableStream` that allows the content of the `Blob` to be read
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as a stream of UTF-8 decoded strings. It is equivalent to piping
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[`blob.stream()`][] through a [`TextDecoderStream`][] set up with UTF-8.
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### `blob.type`
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<!-- YAML
@@ -5610,10 +5622,12 @@ introducing security vulnerabilities into an application.
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[`String.prototype.indexOf()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/indexOf
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[`String.prototype.lastIndexOf()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/lastIndexOf
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[`String.prototype.length`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length
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[`TextDecoderStream`]: webstreams.md#class-textdecoderstream
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[`TypedArray.from()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/from
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[`TypedArray.prototype.set()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/set
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[`TypedArray.prototype.slice()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/slice
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[`TypedArray.prototype.subarray()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/subarray
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[`blob.stream()`]: #blobstream
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[`buf.buffer`]: #bufbuffer
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[`buf.compare()`]: #bufcomparetarget-targetstart-targetend-sourcestart-sourceend
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[`buf.entries()`]: #bufentries
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‎lib/internal/blob.js‎

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+20Lines changed: 20 additions & 0 deletions
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@@ -85,6 +85,7 @@ const kNotCloneable = Symbol('kNotCloneable');
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const disallowedTypeCharacters = /[^\u{0020}-\u{007E}]/u;
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let ReadableStream;
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let TextDecoderStream;
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const enc = new TextEncoder();
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let dec;
@@ -100,6 +101,13 @@ function lazyReadableStream(options) {
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return new ReadableStream(options);
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}
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function lazyTextDecoderStream() {
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// eslint-disable-next-line no-global-assign
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TextDecoderStream ??=
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require('internal/webstreams/encoding').TextDecoderStream;
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return new TextDecoderStream();
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}
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const { EOL } = require('internal/constants');
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function isBlob(object) {
@@ -325,6 +333,17 @@ class Blob {
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throw new ERR_INVALID_THIS('Blob');
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return createBlobReaderStream(this[kHandle].getReader());
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}
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/**
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* @returns {ReadableStream}
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*/
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textStream() {
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if (!isBlob(this))
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throw new ERR_INVALID_THIS('Blob');
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const stream = createBlobReaderStream(this[kHandle].getReader());
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const decoder = lazyTextDecoderStream();
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return stream.pipeThrough(decoder);
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}
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}
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function TransferableBlob(handle, length, type = '') {
@@ -358,6 +377,7 @@ ObjectDefineProperties(Blob.prototype, {
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type: kEnumerableProperty,
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slice: kEnumerableProperty,
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stream: kEnumerableProperty,
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textStream: kEnumerableProperty,
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text: kEnumerableProperty,
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arrayBuffer: kEnumerableProperty,
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bytes: kEnumerableProperty,
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‎test/parallel/test-blob.js‎

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+20-1Lines changed: 20 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -3,7 +3,7 @@
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const common = require('../common');
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const assert = require('assert');
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const { Blob } = require('buffer');
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const { Blob, File } = require('buffer');
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const { inspect } = require('util');
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const { EOL } = require('os');
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const { kState } = require('internal/webstreams/util');
@@ -524,3 +524,22 @@ assert.throws(() => new Blob({}), {
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Blob.prototype.arrayBuffer = arrayBuffer;
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}
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})().then(common.mustCall());
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{
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assert.strictEqual(typeof Blob.prototype.textStream, 'function');
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assert.strictEqual(typeof File.prototype.textStream, 'function');
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assert.strictEqual(File.prototype.textStream, Blob.prototype.textStream);
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}
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(async () => {
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const smiley = Buffer.from('😀', 'utf8');
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const blob = new Blob(['hello ', smiley.subarray(0, 2), smiley.subarray(2)]);
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const stream = blob.textStream();
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assert.ok(stream instanceof ReadableStream);
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let result = '';
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for await (const chunk of stream) {
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assert.strictEqual(typeof chunk, 'string');
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result += chunk;
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}
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assert.strictEqual(result, 'hello 😀');
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})().then(common.mustCall());

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