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Fix a few thing with compose

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This commit is contained in:
Lewis Diamond 2019-12-06 16:38:52 -05:00
parent ff2b652ddf
commit 4b806c4d4e
7 changed files with 1351 additions and 1826 deletions
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6
package.json
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@ -1,6 +1,6 @@
{
"name": "@jogogo/mhysa",
"version": "0.0.1-beta.4",
"version": "0.1.0-alpha.1",
"description": "Streams and event emitter utils for Node.js",
"keywords": [
"promise",
@ -35,7 +35,7 @@
"type": "git"
},
"scripts": {
"test": "NODE_PATH=src node node_modules/.bin/ava 'tests/*.spec.ts' -e",
"test": "NODE_PATH=src node node_modules/.bin/ava tests/*.spec.ts -e",
"test:debug": "NODE_PATH=src node inspect node_modules/ava/profile.js",
"test:all": "NODE_PATH=src node node_modules/.bin/ava",
"lint": "tslint -p tsconfig.json",
@ -47,7 +47,7 @@
"@types/chai": "^4.1.7",
"@types/node": "^12.7.2",
"@types/sinon": "^7.0.13",
"ava": "^1.0.0-rc.2",
"ava": "^2.4.0",
"chai": "^4.2.0",
"mhysa": "./",
"prettier": "^1.14.3",

115
src/functions/compose.ts
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@ -1,16 +1,17 @@
import { pipeline, Duplex, DuplexOptions } from "stream";
import { pipeline, TransformOptions, Transform } from "stream";
export function compose(
streams: Array<
NodeJS.ReadableStream | NodeJS.ReadWriteStream | NodeJS.WritableStream
>,
options?: DuplexOptions,
errorCallback?: (err: any) => void,
options?: TransformOptions,
): Compose {
if (streams.length < 2) {
throw new Error("At least two streams are required to compose");
}
return new Compose(streams, options);
return new Compose(streams, errorCallback, options);
}
enum EventSubscription {
@ -20,46 +21,72 @@ enum EventSubscription {
Self,
}
const eventsTarget = {
close: EventSubscription.Last,
data: EventSubscription.Last,
drain: EventSubscription.Self,
end: EventSubscription.Last,
error: EventSubscription.Self,
finish: EventSubscription.Last,
pause: EventSubscription.Last,
pipe: EventSubscription.First,
readable: EventSubscription.Last,
resume: EventSubscription.Last,
unpipe: EventSubscription.First,
};
type AllStreams =
| NodeJS.ReadableStream
| NodeJS.ReadWriteStream
| NodeJS.WritableStream;
export class Compose extends Duplex {
function isReadable(stream: AllStreams): stream is NodeJS.WritableStream {
return (
(stream as NodeJS.ReadableStream).pipe !== undefined &&
(stream as any).readable === true
);
}
export class Compose extends Transform {
private first: AllStreams;
private last: AllStreams;
private streams: AllStreams[];
private inputStream: ReadableStream;
constructor(streams: AllStreams[], options?: DuplexOptions) {
constructor(
streams: AllStreams[],
errorCallback?: (err: any) => void,
options?: TransformOptions,
) {
super(options);
this.first = streams[0];
this.last = streams[streams.length - 1];
this.streams = streams;
pipeline(streams, (err: any) => {
this.emit("error", err);
pipeline(
streams,
errorCallback ||
((error: any) => {
if (error) {
this.emit("error", error);
}
}),
);
if (isReadable(this.last)) {
(this.last as NodeJS.ReadWriteStream).pipe(
new Transform({
...options,
transform: (d: any, encoding, cb) => {
this.push(d);
cb();
},
}),
);
}
}
public _transform(chunk: any, encoding: string, cb: any) {
(this.first as NodeJS.WritableStream).write(chunk, encoding, cb);
}
public _flush(cb: any) {
if (isReadable(this.first)) {
(this.first as any).push(null);
}
this.last.once("end", () => {
cb();
});
}
public pipe<T extends NodeJS.WritableStream>(dest: T) {
return (this.last as NodeJS.ReadableStream).pipe(dest);
}
public _write(chunk: any, encoding: string, cb: any) {
(this.first as NodeJS.WritableStream).write(chunk, encoding, cb);
public _destroy(error: any, cb: (error?: any) => void) {
this.streams.forEach(s => (s as any).destroy());
cb(error);
}
public bubble(...events: string[]) {
@ -69,38 +96,4 @@ export class Compose extends Duplex {
});
});
}
public on(event: string, cb: any) {
switch (eventsTarget[event]) {
case EventSubscription.First:
this.first.on(event, cb);
break;
case EventSubscription.Last:
this.last.on(event, cb);
break;
case EventSubscription.All:
this.streams.forEach(s => s.on(event, cb));
break;
default:
super.on(event, cb);
}
return this;
}
public once(event: string, cb: any) {
switch (eventsTarget[event]) {
case EventSubscription.First:
this.first.once(event, cb);
break;
case EventSubscription.Last:
this.last.once(event, cb);
break;
case EventSubscription.All:
this.streams.forEach(s => s.once(event, cb));
break;
default:
super.once(event, cb);
}
return this;
}
}

7
src/functions/index.ts
View File

@ -121,6 +121,10 @@ export default function mhysa(defaultOptions?: TransformOptions) {
/**
* Return a ReadWrite stream that parses the streamed chunks as JSON. Each streamed chunk
* must be a fully defined JSON string in utf8.
* @param format: @type SerializationFormats defaults SerializationFormats.utf8
* @param emitError: @type boolean Whether or not to emit an error when
* failing to parse. An error will automatically close the stream.
* Defaults to true.
*/
parse,
@ -245,9 +249,10 @@ export default function mhysa(defaultOptions?: TransformOptions) {
/**
* Composes multiple streams together. Writing occurs on first stream, piping occurs from last stream.
* @param streams Array of streams to compose. Minimum of two.
* @param errorCallback a function that handles any error coming out of the pipeline
* @param options Transform stream options
*/
compose: withDefaultOptions(1, compose),
compose: withDefaultOptions(2, compose),
/**
* Composes multiple streams together. Writing occurs on first stream, piping occurs from last stream.

9
src/functions/parse.ts
View File

@ -4,6 +4,7 @@ import { SerializationFormats } from "./baseDefinitions";
export function parse(
format: SerializationFormats = SerializationFormats.utf8,
emitError: boolean = true,
): Transform {
const decoder = new StringDecoder(format);
return new Transform({
@ -13,9 +14,13 @@ export function parse(
try {
const asString = decoder.write(chunk);
// Using await causes parsing errors to be emitted
callback(undefined, await JSON.parse(asString));
callback(null, await JSON.parse(asString));
} catch (err) {
callback(err);
if (emitError) {
callback(err);
} else {
callback();
}
}
},
});

306
tests/compose.spec.ts
View File

@ -1,6 +1,7 @@
const test = require("ava");
const { expect } = require("chai");
const { sleep } = require("../src/helpers");
import * as test from "ava";
import { expect } from "chai";
import { sleep } from "../src/helpers";
import { Readable, Writable } from "stream";
import mhysa from "../src";
import { performance } from "perf_hooks";
const { compose, map } = mhysa({ objectMode: true });
@ -22,10 +23,7 @@ test.cb("compose() chains two streams together in the correct order", t => {
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true },
);
const composed = compose([first, second]);
composed.on("data", data => {
expect(data).to.deep.equal(result[i]);
@ -35,12 +33,6 @@ test.cb("compose() chains two streams together in the correct order", t => {
t.end();
}
});
composed.on("error", err => {
t.end(err);
});
composed.on("end", () => {
t.end();
});
const input = [
{ key: "a", visited: [] },
@ -72,10 +64,7 @@ test.cb("piping compose() maintains correct order", t => {
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true },
);
const composed = compose([first, second]);
const third = map((chunk: Chunk) => {
chunk.visited.push(3);
return chunk;
@ -115,28 +104,19 @@ test("compose() writable length should be less than highWaterMark when handing w
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const first = map(async (chunk: Chunk) => {
chunk.mapped.push(1);
return chunk;
});
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const second = map(async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 2 },
);
const composed = compose([first, second], undefined, {
highWaterMark: 2,
});
composed.on("error", err => {
reject();
});
@ -180,29 +160,20 @@ test("compose() should emit drain event ~rate * highWaterMark ms for every write
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const first = map(async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
});
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const second = map(async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark },
);
const composed = compose([first, second], undefined, {
highWaterMark,
});
composed.on("error", err => {
reject();
});
@ -255,29 +226,20 @@ test.cb(
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const first = map(async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
});
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const second = map(async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 5 },
);
const composed = compose([first, second], undefined, {
highWaterMark: 5,
});
composed.on("error", err => {
t.end(err);
@ -322,15 +284,10 @@ test.cb(
key: string;
mapped: number[];
}
const first = map(
(chunk: Chunk) => {
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const first = map((chunk: Chunk) => {
chunk.mapped.push(1);
return chunk;
});
const second = map(
async (chunk: Chunk) => {
@ -341,13 +298,12 @@ test.cb(
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 5 },
);
const composed = compose([first, second], undefined, {
highWaterMark: 5,
});
composed.on("error", err => {
t.end(err);
});
@ -398,7 +354,6 @@ test.cb(
return chunk;
},
{
objectMode: true,
highWaterMark: 2,
},
);
@ -410,13 +365,12 @@ test.cb(
chunk.mapped.push("second");
return chunk;
},
{ objectMode: true, highWaterMark: 2 },
{ highWaterMark: 2 },
);
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 5 },
);
const composed = compose([first, second], undefined, {
highWaterMark: 5,
});
composed.on("error", err => {
t.end(err);
});
@ -458,29 +412,20 @@ test.cb(
key: string;
mapped: number[];
}
const first = map(
async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
},
{
objectMode: true,
},
);
const first = map(async (chunk: Chunk) => {
await sleep(_rate);
chunk.mapped.push(1);
return chunk;
});
const second = map(
async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true },
);
const second = map(async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
});
const composed = compose(
[first, second],
{ objectMode: true, highWaterMark: 6 },
);
const composed = compose([first, second], undefined, {
highWaterMark: 6,
});
composed.on("error", err => {
t.end(err);
@ -510,3 +455,124 @@ test.cb(
});
},
);
test.cb("compose() should be 'destroyable'", t => {
t.plan(3);
const _sleep = 100;
interface Chunk {
key: string;
mapped: number[];
}
const first = map(async (chunk: Chunk) => {
await sleep(_sleep);
chunk.mapped.push(1);
return chunk;
});
const second = map(async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
});
const composed = compose([first, second], (err: any) => {
t.pass();
});
const fakeSource = new Readable({
objectMode: true,
read() {
return;
},
});
const fakeSink = new Writable({
objectMode: true,
write(data, enc, cb) {
const cur = input.shift();
t.is(cur.key, data.key);
t.deepEqual(cur.mapped, [1, 2]);
if (cur.key === "a") {
composed.destroy();
}
cb();
},
});
composed.on("close", t.end);
fakeSource.pipe(composed).pipe(fakeSink);
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
fakeSource.push(input[0]);
fakeSource.push(input[1]);
fakeSource.push(input[2]);
fakeSource.push(input[3]);
fakeSource.push(input[4]);
});
test.cb("compose() `finish` and `end` propagates", t => {
interface Chunk {
key: string;
mapped: number[];
}
t.plan(8);
const first = map(async (chunk: Chunk) => {
chunk.mapped.push(1);
return chunk;
});
const second = map(async (chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
});
const composed = compose([first, second], undefined, {
highWaterMark: 3,
});
const fakeSource = new Readable({
objectMode: true,
read() {
return;
},
});
const sink = map((d: Chunk) => {
const curr = input.shift();
t.is(curr.key, d.key);
t.deepEqual(d.mapped, [1, 2]);
});
fakeSource.pipe(composed).pipe(sink);
fakeSource.on("end", () => {
t.pass();
});
composed.on("finish", () => {
t.pass();
});
composed.on("end", () => {
t.pass();
t.end();
});
sink.on("finish", () => {
t.pass();
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
fakeSource.push(input[0]);
fakeSource.push(input[1]);
fakeSource.push(null);
});

12
tests/parse.spec.ts
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@ -1,4 +1,4 @@
import { Readable } from "stream";
import { Readable, finished } from "stream";
import test from "ava";
import { expect } from "chai";
import mhysa from "../src";
@ -26,13 +26,17 @@ test.cb("parse() parses the streamed elements as JSON", t => {
});
test.cb("parse() emits errors on invalid JSON", t => {
t.plan(2);
t.plan(1);
const source = new Readable({ objectMode: true });
source
.pipe(parse())
.resume()
.on("error", () => t.pass())
.on("end", t.end);
.on("error", (d: any) => {
t.pass();
t.end();
})
.on("end", t.fail);
source.push("{}");
source.push({});

2722
yarn.lock
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