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