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Review Summary
I am requesting changes because the implementation does not satisfy the explicit Streams requirement on the server side [CHECKLIST ITEM #11], even though most other functional requirements are correctly met.
Critical issues that must be fixed:
- In
src/createServer.js, the upload handler currently reads the entire file into memory usingfs.readFileand then compresses it with buffer-based helpers likezlib.gzip,zlib.deflate, andzlib.brotliCompress; this violates the requirement to use streaming I/O and will not scale for large files. Instead, you should switch to a streaming pipeline such as:const readStream = fs.createReadStream(filePath);const compressor = zlib.createGzip()/zlib.createDeflate()/zlib.createBrotliCompress()chosen from yourcompressionTypesmap.- Pipe them into the response:
readStream.pipe(compressor).pipe(res);, settingContent-TypeandContent-Dispositionheaders before starting the pipe, and adding.on('error', ...)handlers on the streams to send a 400/500 and cleanly end the response.
- The
compressionTypesmappings in bothsrc/createServer.jsand the logic tied tosrc/index.htmlcurrently refer to callback-based functions (e.g.zlib.gzip); these need to be updated to store the corresponding stream factory functions (zlib.createGzip,zlib.createDeflate,zlib.createBrotliCompress) so that your request handler can consistently create transform streams instead of compressing buffers.
Minor improvements (optional but recommended):
- When setting the
Content-Dispositionheader, quote the filename (e.g.attachment; filename="${safeName}.${ext}") to avoid issues with spaces or special characters.
Your form, routing, validation, and extension mapping are all well done, so once you refactor the compression path to use Node.js streams as described, your solution will fully align with the task requirements.
✨ Please rate this review in the Platform's notification center1. I will be grateful for your feedback! ✨
Important
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Footnotes
| fs.readFile(filePath, (readError, fileBuffer) => { | ||
| if (readError) { | ||
| sendBadRequest(response); | ||
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| return; | ||
| } | ||
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| const { compress, extension } = compressionTypes[compressionType]; | ||
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| compress(fileBuffer, (compressError, compressed) => { | ||
| if (compressError) { | ||
| sendBadRequest(response); | ||
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| return; | ||
| } | ||
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| response.writeHead(200, { | ||
| 'Content-Type': 'application/octet-stream', | ||
| 'Content-Disposition': `attachment; filename=${filename}.${extension}`, | ||
| }); | ||
| response.end(compressed); | ||
| }); |
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The server reads the entire uploaded file into memory using fs.readFile and then calls the non-stream zlib functions. This doesn't meet checklist item #11 which requires using Streams. Consider using fs.createReadStream(filePath) and piping it through the appropriate zlib transform (zlib.createGzip(), zlib.createDeflate(), or zlib.createBrotliCompress()) into the HTTP response to stream the compressed data.
| const compressionTypes = { | ||
| gzip: { | ||
| compress: zlib.gzip, | ||
| extension: 'gz', | ||
| }, | ||
| deflate: { | ||
| compress: zlib.deflate, | ||
| extension: 'dfl', | ||
| }, | ||
| br: { | ||
| compress: zlib.brotliCompress, | ||
| extension: 'br', | ||
| }, | ||
| }; |
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The compressionTypes object maps to zlib.gzip, zlib.deflate, and zlib.brotliCompress (buffer-based functions). To comply with the Streams requirement (checklist item #11) replace these with the streaming compressors (zlib.createGzip, zlib.createDeflate, zlib.createBrotliCompress) and update the request handling to pipe streams instead of compressing buffers.
| <h1>Compress a file</h1> | ||
| <form action="/compress" method="post" enctype="multipart/form-data"> | ||
| <label> | ||
| Choose file: | ||
| <input type="file" name="file" required /> | ||
| </label> | ||
| <br /> | ||
| <label> | ||
| Compression type: | ||
| <select name="compressionType" required> | ||
| <option value="gzip">gzip</option> | ||
| <option value="deflate">deflate</option> | ||
| <option value="br">br</option> | ||
| </select> |
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compressionTypes maps compress to the callback-based zlib functions (zlib.gzip, zlib.deflate, zlib.brotliCompress). To use streams you should instead store the stream factory functions (zlib.createGzip, zlib.createDeflate, zlib.createBrotliCompress) or otherwise adapt the code to create appropriate transform streams. This change is necessary for implementing streaming compression (checklist item #11).
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