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'use strict';
const common = require('../common');
const {
Readable,
} = require('stream');
const assert = require('assert');
const { once } = require('events');
const { setTimeout } = require('timers/promises');
{
// Map works on synchronous streams with a synchronous mapper
const stream = Readable.from([1, 2, 3, 4, 5]).map((x) => x + x);
(async () => {
assert.deepStrictEqual(await stream.toArray(), [2, 4, 6, 8, 10]);
})().then(common.mustCall());
}
{
// Map works on synchronous streams with an asynchronous mapper
const stream = Readable.from([1, 2, 3, 4, 5]).map(async (x) => {
await Promise.resolve();
return x + x;
});
(async () => {
assert.deepStrictEqual(await stream.toArray(), [2, 4, 6, 8, 10]);
})().then(common.mustCall());
}
{
// Map works on asynchronous streams with a asynchronous mapper
const stream = Readable.from([1, 2, 3, 4, 5]).map(async (x) => {
return x + x;
}).map((x) => x + x);
(async () => {
assert.deepStrictEqual(await stream.toArray(), [4, 8, 12, 16, 20]);
})().then(common.mustCall());
}
{
// Map works on an infinite stream
const stream = Readable.from(async function* () {
while (true) yield 1;
}()).map(common.mustCall(async (x) => {
return x + x;
}, 5));
(async () => {
let i = 1;
for await (const item of stream) {
assert.strictEqual(item, 2);
if (++i === 5) break;
}
})().then(common.mustCall());
}
{
// Map works on non-objectMode streams
const stream = new Readable({
read() {
this.push(Uint8Array.from([1]));
this.push(Uint8Array.from([2]));
this.push(null);
}
}).map(async ([x]) => {
return x + x;
}).map((x) => x + x);
const result = [4, 8];
(async () => {
for await (const item of stream) {
assert.strictEqual(item, result.shift());
}
})().then(common.mustCall());
}
{
// Does not care about data events
const source = new Readable({
read() {
this.push(Uint8Array.from([1]));
this.push(Uint8Array.from([2]));
this.push(null);
}
});
setImmediate(() => stream.emit('data', Uint8Array.from([1])));
const stream = source.map(async ([x]) => {
return x + x;
}).map((x) => x + x);
const result = [4, 8];
(async () => {
for await (const item of stream) {
assert.strictEqual(item, result.shift());
}
})().then(common.mustCall());
}
{
// Emitting an error during `map`
const stream = Readable.from([1, 2, 3, 4, 5]).map(async (x) => {
if (x === 3) {
stream.emit('error', new Error('boom'));
}
return x + x;
});
assert.rejects(
stream.map((x) => x + x).toArray(),
/boom/,
).then(common.mustCall());
}
{
// Throwing an error during `map` (sync)
const stream = Readable.from([1, 2, 3, 4, 5]).map((x) => {
if (x === 3) {
throw new Error('boom');
}
return x + x;
});
assert.rejects(
stream.map((x) => x + x).toArray(),
/boom/,
).then(common.mustCall());
}
{
// Throwing an error during `map` (async)
const stream = Readable.from([1, 2, 3, 4, 5]).map(async (x) => {
if (x === 3) {
throw new Error('boom');
}
return x + x;
});
assert.rejects(
stream.map((x) => x + x).toArray(),
/boom/,
).then(common.mustCall());
}
{
// Concurrency + AbortSignal
const ac = new AbortController();
const range = Readable.from([1, 2, 3, 4, 5]);
const stream = range.map(common.mustCall(async (_, { signal }) => {
await once(signal, 'abort');
throw signal.reason;
}, 2), { signal: ac.signal, concurrency: 2 });
// pump
assert.rejects(async () => {
for await (const item of stream) {
assert.fail('should not reach here, got ' + item);
}
}, {
name: 'AbortError',
}).then(common.mustCall());
setImmediate(() => {
ac.abort();
});
}
{
// Concurrency result order
const stream = Readable.from([1, 2]).map(async (item, { signal }) => {
await setTimeout(10 - item, { signal });
return item;
}, { concurrency: 2 });
(async () => {
const expected = [1, 2];
for await (const item of stream) {
assert.strictEqual(item, expected.shift());
}
})().then(common.mustCall());
}
{
// Error cases
assert.throws(() => Readable.from([1]).map(1), /ERR_INVALID_ARG_TYPE/);
assert.throws(() => Readable.from([1]).map((x) => x, {
concurrency: 'Foo'
}), /ERR_OUT_OF_RANGE/);
assert.throws(() => Readable.from([1]).map((x) => x, 1), /ERR_INVALID_ARG_TYPE/);
assert.throws(() => Readable.from([1]).map((x) => x, { signal: true }), /ERR_INVALID_ARG_TYPE/);
}
{
// Test result is a Readable
const stream = Readable.from([1, 2, 3, 4, 5]).map((x) => x);
assert.strictEqual(stream.readable, true);
}
|
