strom/tests/compose.spec.ts
2019-09-26 10:36:36 -04:00

512 lines
13 KiB
TypeScript

const test = require("ava");
const { expect } = require("chai");
const { compose, map } = require("../src");
const { sleep } = require("../src/helpers");
import { performance } from "perf_hooks";
test.cb("compose() chains two streams together in the correct order", t => {
t.plan(3);
interface Chunk {
visited: number[];
key: string;
}
let i = 0;
const first = map((chunk: Chunk) => {
chunk.visited.push(1);
return chunk;
});
const second = map((chunk: Chunk) => {
chunk.visited.push(2);
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true },
);
composed.on("data", data => {
expect(data).to.deep.equal(result[i]);
t.pass();
i++;
if (i === 3) {
t.end();
}
});
composed.on("error", err => {
t.end(err);
});
composed.on("end", () => {
t.end();
});
const input = [
{ key: "a", visited: [] },
{ key: "b", visited: [] },
{ key: "c", visited: [] },
];
const result = [
{ key: "a", visited: [1, 2] },
{ key: "b", visited: [1, 2] },
{ key: "c", visited: [1, 2] },
];
input.forEach(item => composed.write(item));
});
test.cb("piping compose() maintains correct order", t => {
t.plan(3);
interface Chunk {
visited: number[];
key: string;
}
let i = 0;
const first = map((chunk: Chunk) => {
chunk.visited.push(1);
return chunk;
});
const second = map((chunk: Chunk) => {
chunk.visited.push(2);
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true },
);
const third = map((chunk: Chunk) => {
chunk.visited.push(3);
return chunk;
});
composed.pipe(third).on("data", data => {
expect(data).to.deep.equal(result[i]);
t.pass();
i++;
if (i === 3) {
t.end();
}
});
composed.on("error", err => {
t.end(err);
});
const input = [
{ key: "a", visited: [] },
{ key: "b", visited: [] },
{ key: "c", visited: [] },
];
const result = [
{ key: "a", visited: [1, 2, 3] },
{ key: "b", visited: [1, 2, 3] },
{ key: "c", visited: [1, 2, 3] },
];
input.forEach(item => composed.write(item));
});
test("compose() writable length should be less than highWaterMark when handing writes", async t => {
t.plan(7);
return new Promise(async (resolve, reject) => {
interface Chunk {
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 2 },
);
composed.on("error", err => {
reject();
});
composed.on("drain", () => {
t.pass();
expect(composed._writableState.length).to.be.equal(0);
});
composed.on("data", (chunk: Chunk) => {
if (chunk.key === "e") {
resolve();
}
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
for (const item of input) {
const res = composed.write(item);
expect(composed._writableState.length).to.be.at.most(2);
t.pass();
if (!res) {
await sleep(10);
}
}
});
});
test("compose() should emit drain event ~rate * highWaterMark ms for every write that causes backpressure", async t => {
t.plan(7);
const _rate = 100;
const highWaterMark = 2;
return new Promise(async (resolve, reject) => {
interface Chunk {
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark },
);
composed.on("error", err => {
reject();
});
composed.on("drain", () => {
t.pass();
expect(composed._writableState.length).to.be.equal(0);
expect(performance.now() - start).to.be.closeTo(
_rate * highWaterMark,
10,
);
});
composed.on("data", (chunk: Chunk) => {
pendingReads--;
if (pendingReads === 0) {
resolve();
}
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
let start = performance.now();
let pendingReads = input.length;
start = performance.now();
for (const item of input) {
const res = composed.write(item);
expect(composed._writableState.length).to.be.at.most(highWaterMark);
t.pass();
if (!res) {
await sleep(_rate * highWaterMark * 2);
start = performance.now();
}
}
});
});
test.cb(
"compose() should emit drain event after 500 ms when writing 5 items that take 100ms to process with a highWaterMark of 5 ",
t => {
t.plan(6);
const _rate = 100;
interface Chunk {
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 5 },
);
composed.on("error", err => {
t.end(err);
});
composed.on("drain", () => {
expect(composed._writableState.length).to.be.equal(0);
expect(performance.now() - start).to.be.closeTo(
_rate * input.length,
25,
);
t.pass();
});
composed.on("data", (chunk: Chunk) => {
t.pass();
if (chunk.key === "e") {
t.end();
}
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
input.forEach(item => {
composed.write(item);
});
const start = performance.now();
},
);
test.cb(
"compose() should emit drain event immediately when second stream is bottleneck",
t => {
t.plan(6);
const _rate = 200;
interface Chunk {
key: string;
mapped: number[];
}
const first = map(
(chunk: Chunk) => {
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const second = map(
async (chunk: Chunk) => {
pendingReads--;
await sleep(_rate);
expect(second._writableState.length).to.be.equal(1);
expect(first._readableState.length).to.equal(pendingReads);
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 5 },
);
composed.on("error", err => {
t.end(err);
});
composed.on("drain", () => {
expect(composed._writableState.length).to.be.equal(0);
expect(performance.now() - start).to.be.lessThan(_rate);
t.pass();
});
composed.on("data", (chunk: Chunk) => {
expect(composed._writableState.length).to.be.equal(0);
t.pass();
if (chunk.key === "e") {
t.end();
}
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
let pendingReads = input.length;
input.forEach(item => {
composed.write(item);
});
const start = performance.now();
},
);
test.cb(
"compose() should emit drain event and first should contain up to highWaterMark items in readable state when second is bottleneck",
t => {
t.plan(6);
interface Chunk {
index: number;
mapped: string[];
}
const first = map(
async (chunk: Chunk) => {
expect(first._readableState.length).to.be.at.most(2);
chunk.mapped.push("first");
return chunk;
},
{
objectMode: true,
highWaterMark: 2,
},
);
const second = map(
async (chunk: Chunk) => {
expect(second._writableState.length).to.be.equal(1);
await sleep(100);
chunk.mapped.push("second");
return chunk;
},
{ objectMode: true, highWaterMark: 2 },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 5 },
);
composed.on("error", err => {
t.end(err);
});
composed.on("data", (chunk: Chunk) => {
expect(chunk.mapped.length).to.equal(2);
expect(chunk.mapped).to.deep.equal(["first", "second"]);
t.pass();
if (chunk.index === 5) {
t.end();
}
});
composed.on("drain", () => {
expect(composed._writableState.length).to.be.equal(0);
t.pass();
});
const input = [
{ index: 1, mapped: [] },
{ index: 2, mapped: [] },
{ index: 3, mapped: [] },
{ index: 4, mapped: [] },
{ index: 5, mapped: [] },
];
input.forEach(item => {
composed.write(item);
});
},
);
test.cb(
"compose() should not emit drain event writing 5 items to compose with a highWaterMark of 6",
t => {
t.plan(5);
const _rate = 100;
interface Chunk {
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 6 },
);
composed.on("error", err => {
t.end(err);
});
composed.on("drain", () => {
t.end(new Error("Drain should not be emitted"));
});
composed.on("data", (chunk: Chunk) => {
t.pass();
if (chunk.key === "e") {
t.end();
}
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
input.forEach(item => {
composed.write(item);
});
},
);