我在阅读NodeJS文档中读出的19个套路 - 开发者俱乐部

const weirdoString = `name:Sophie;shape:fox;condition:new`;
const result = querystring.parse(weirdoString, `;`, `:`);
// result:
// {
// name: `Sophie`,
// shape: `fox`,
// condition: `new`,
// };

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require(`http`)
.createServer()
.listen({
port: 8080,
host: `localhost`,
})
.on(`request`, (req, res) => {
res.end(`Hello World!`);
});

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const fs = require(`fs`);
const path = require(`path`);
// why have I always done this...
fs.readFile(path.join(__dirname, `myFile.txt`), (err, data) => {
// do something
});
// when I could just do this?
fs.readFile(`./path/to/myFile.txt`, (err, data) => {
// do something
});

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myFilePath = `/someDir/someFile.json`;
path.parse(myFilePath).base === `someFile.json`; // true
path.parse(myFilePath).name === `someFile`; // true
path.parse(myFilePath).ext === `.json`; // true

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const dailyCleanup = setInterval(() => {
cleanup();
}, 1000 * 60 * 60 * 24);
dailyCleanup.unref();
Use Signal Constants

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const fs = require(`fs`);
// bad
fs.readFile(`./myFile.txt`, `utf8`, (err, data) => {
data.split(`\r\n`).forEach(line => {
// do something
});
});
// good
const os = require(`os`);
fs.readFile(`./myFile.txt`, `utf8`, (err, data) => {
data.split(os.EOL).forEach(line => {
// do something
});
});

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// This makes two connections, one to a tcp server, one to an http server (both in server.js)
// It fires off a bunch of connections and times the response
// Both send strings.
const net = require(`net`);
const http = require(`http`);
function parseIncomingMessage(res) {
return new Promise((resolve) => {
let data = ``;
res.on(`data`, (chunk) => {
data += chunk;
});
res.on(`end`, () => resolve(data));
});
}
const testLimit = 5000;
/* ------------------ */
/* -- NET client -- */
/* ------------------ */
function testNetClient() {
const netTest = {
startTime: process.hrtime(),
responseCount: 0,
testCount: 0,
payloadData: {
type: `millipede`,
feet: 100,
test: 0,
},
};
function handleSocketConnect() {
netTest.payloadData.test++;
netTest.payloadData.feet++;
const payload = JSON.stringify(netTest.payloadData);
this.end(payload, `utf8`);
}
function handleSocketData() {
netTest.responseCount++;
if (netTest.responseCount === testLimit) {
const hrDiff = process.hrtime(netTest.startTime);
const elapsedTime = hrDiff[0] * 1e3 + hrDiff[1] / 1e6;
const requestsPerSecond = (testLimit / (elapsedTime / 1000)).toLocaleString();
console.info(`net.Server handled an average of ${requestsPerSecond} requests per second.`);
}
}
while (netTest.testCount < testLimit) {
netTest.testCount++;
const socket = net.connect(8888, handleSocketConnect);
socket.on(`data`, handleSocketData);
}
}
/* ------------------- */
/* -- HTTP client -- */
/* ------------------- */
function testHttpClient() {
const httpTest = {
startTime: process.hrtime(),
responseCount: 0,
testCount: 0,
};
const payloadData = {
type: `centipede`,
feet: 100,
test: 0,
};
const options = {
hostname: `localhost`,
port: 8080,
method: `POST`,
headers: {
'Content-Type': `application/x-www-form-urlencoded`,
},
};
function handleResponse(res) {
parseIncomingMessage(res).then(() => {
httpTest.responseCount++;
if (httpTest.responseCount === testLimit) {
const hrDiff = process.hrtime(httpTest.startTime);
const elapsedTime = hrDiff[0] * 1e3 + hrDiff[1] / 1e6;
const requestsPerSecond = (testLimit / (elapsedTime / 1000)).toLocaleString();
console.info(`http.Server handled an average of ${requestsPerSecond} requests per second.`);
}
});
}
while (httpTest.testCount < testLimit) {
httpTest.testCount++;
payloadData.test = httpTest.testCount;
payloadData.feet++;
const payload = JSON.stringify(payloadData);
options[`Content-Length`] = Buffer.byteLength(payload);
const req = http.request(options, handleResponse);
req.end(payload);
}
}
/* -- Start tests -- */
// flip these occasionally to ensure there's no bias based on order
setTimeout(() => {
console.info(`Starting testNetClient()`);
testNetClient();
}, 50);
setTimeout(() => {
console.info(`Starting testHttpClient()`);
testHttpClient();
}, 2000);
// This sets up two servers. A TCP and an HTTP one.
// For each response, it parses the received string as JSON, converts that object and returns a string
const net = require(`net`);
const http = require(`http`);
function renderAnimalString(jsonString) {
const data = JSON.parse(jsonString);
return `${data.test}: your are a ${data.type} and you have ${data.feet} feet.`;
}
/* ------------------ */
/* -- NET server -- */
/* ------------------ */
net
.createServer((socket) => {
socket.on(`data`, (jsonString) => {
socket.end(renderAnimalString(jsonString));
});
})
.listen(8888);
/* ------------------- */
/* -- HTTP server -- */
/* ------------------- */
function parseIncomingMessage(res) {
return new Promise((resolve) => {
let data = ``;
res.on(`data`, (chunk) => {
data += chunk;
});
res.on(`end`, () => resolve(data));
});
}
http
.createServer()
.listen(8080)
.on(`request`, (req, res) => {
parseIncomingMessage(req).then((jsonString) => {
res.end(renderAnimalString(jsonString));
});
});

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