Node.js · Theory

Stream writable.writableFinished Property

Theory

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Stream writable.writableFinished Property

Stream writable.writableFinished Property sits in an upload job. Kabir’s job is read a big CSV. Write that first.

For Stream writable.writableFinished Property, an Express route is in play. Don’t blame it until you have traced read a big CSV.

Stream writable.writableFinished Property exists so Kabir can keep read a big CSV correct in an upload job.

Kabir ships Stream writable.writableFinished Property in an upload job. That is the use case worth saying.

Stream writable.writableFinished Property trap: loading the whole file into RAM. Kabir loses marks for that every viva.

After Stream writable.writableFinished Property, Kabir should still remember loading the whole file into RAM.

One breath for Stream writable.writableFinished Property, then read a big CSV, then loading the whole file into RAM. Sit down.

Exam tip

Say Stream writable.writableFinished Property in one breath, then createReadStream, then loading the whole file into RAM.

Example

const fs = require("fs");
const path = require("path");

const file = path.join(__dirname || ".", "demo.txt");
fs.writeFileSync(file, "hello node\n");
const text = fs.readFileSync(file, "utf8");
console.log(text.trim());
fs.unlinkSync(file);

Stream writable.writableFinished Property — fs reads/writes files. Prefer promises/async APIs in real apps.

Short notes

DefStream writable.writableFinished Property — Kabir uses it for read a big CSV in an upload job.
RuleStream writable.writableFinished Property → createReadStream.
RememberStream writable.writableFinished Property + an Express route (an upload job).
UseStream writable.writableFinished Property in an upload job (read a big CSV).
TrapStream writable.writableFinished Property — loading the whole file into RAM.
ExStream writable.writableFinished Property → read a big CSV.

const fs = require("fs"); const path = require("path"); const file = path.join(__dirname || ".", "demo.txt"); fs.writeFileSync(file, "hello node\n"); const text = fs.readFileSync(file, "utf8"); console.log(text.trim()); fs.unlinkSync(file);

Stream writable.writableFinished Property

Example

Short notes

Questions

Stream writable.writableFinished Property

Example

Short notes

Questions