my-idlers/node_modules/decompress-response/index.js

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'use strict';
const {Transform, PassThrough} = require('stream');
const zlib = require('zlib');
const mimicResponse = require('mimic-response');
module.exports = response => {
const contentEncoding = (response.headers['content-encoding'] || '').toLowerCase();
if (!['gzip', 'deflate', 'br'].includes(contentEncoding)) {
return response;
}
// TODO: Remove this when targeting Node.js 12.
const isBrotli = contentEncoding === 'br';
if (isBrotli && typeof zlib.createBrotliDecompress !== 'function') {
response.destroy(new Error('Brotli is not supported on Node.js < 12'));
return response;
}
let isEmpty = true;
const checker = new Transform({
transform(data, _encoding, callback) {
isEmpty = false;
callback(null, data);
},
flush(callback) {
callback();
}
});
const finalStream = new PassThrough({
autoDestroy: false,
destroy(error, callback) {
response.destroy();
callback(error);
}
});
const decompressStream = isBrotli ? zlib.createBrotliDecompress() : zlib.createUnzip();
decompressStream.once('error', error => {
if (isEmpty && !response.readable) {
finalStream.end();
return;
}
finalStream.destroy(error);
});
mimicResponse(response, finalStream);
response.pipe(checker).pipe(decompressStream).pipe(finalStream);
return finalStream;
};