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'use strict';
const { mustCall } = require('../common');
const { once } = require('events');
const { Readable } = require('stream');
const { strictEqual } = require('assert');
async function toReadableBasicSupport() {
async function* generate() {
yield 'a';
yield 'b';
yield 'c';
}
const stream = Readable.from(generate());
const expected = ['a', 'b', 'c'];
for await (const chunk of stream) {
strictEqual(chunk, expected.shift());
}
}
async function toReadableSyncIterator() {
function* generate() {
yield 'a';
yield 'b';
yield 'c';
}
const stream = Readable.from(generate());
const expected = ['a', 'b', 'c'];
for await (const chunk of stream) {
strictEqual(chunk, expected.shift());
}
}
async function toReadablePromises() {
const promises = [
Promise.resolve('a'),
Promise.resolve('b'),
Promise.resolve('c')
];
const stream = Readable.from(promises);
const expected = ['a', 'b', 'c'];
for await (const chunk of stream) {
strictEqual(chunk, expected.shift());
}
}
async function toReadableString() {
const stream = Readable.from('abc');
const expected = ['a', 'b', 'c'];
for await (const chunk of stream) {
strictEqual(chunk, expected.shift());
}
}
async function toReadableOnData() {
async function* generate() {
yield 'a';
yield 'b';
yield 'c';
}
const stream = Readable.from(generate());
let iterations = 0;
const expected = ['a', 'b', 'c'];
stream.on('data', (chunk) => {
iterations++;
strictEqual(chunk, expected.shift());
});
await once(stream, 'end');
strictEqual(iterations, 3);
}
async function toReadableOnDataNonObject() {
async function* generate() {
yield 'a';
yield 'b';
yield 'c';
}
const stream = Readable.from(generate(), { objectMode: false });
let iterations = 0;
const expected = ['a', 'b', 'c'];
stream.on('data', (chunk) => {
iterations++;
strictEqual(chunk instanceof Buffer, true);
strictEqual(chunk.toString(), expected.shift());
});
await once(stream, 'end');
strictEqual(iterations, 3);
}
async function destroysTheStreamWhenThrowing() {
async function* generate() {
throw new Error('kaboom');
}
const stream = Readable.from(generate());
stream.read();
const [err] = await once(stream, 'error');
strictEqual(err.message, 'kaboom');
strictEqual(stream.destroyed, true);
}
async function asTransformStream() {
async function* generate(stream) {
for await (const chunk of stream) {
yield chunk.toUpperCase();
}
}
const source = new Readable({
objectMode: true,
read() {
this.push('a');
this.push('b');
this.push('c');
this.push(null);
}
});
const stream = Readable.from(generate(source));
const expected = ['A', 'B', 'C'];
for await (const chunk of stream) {
strictEqual(chunk, expected.shift());
}
}
Promise.all([
toReadableBasicSupport(),
toReadableSyncIterator(),
toReadablePromises(),
toReadableString(),
toReadableOnData(),
toReadableOnDataNonObject(),
destroysTheStreamWhenThrowing(),
asTransformStream()
]).then(mustCall());
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