Interview Q&A / Node.js
Node.js interview questions
The event loop on the server, streams, modules and building APIs with Express.
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- Write an Express middleware that checks a JWT and protects a route.
Read the Bearer token from the Authorization header, verify it with jwt.verify, attach the claims to req.user and call next. On a missing or invalid token, respond 401 without calling next.
BeginnerQuick answerCoding1 min read - Write a Transform stream that converts incoming text to uppercase.
Extend stream.Transform (or pass a transform function), call this.push with the changed chunk, and call the callback when done. Then pipe a readable into it and into a writable.
IntermediateQuick answerCoding1 min read