@nestjs/platform-fastify/multipart/storage/memory.storage.js

Run NestJS on Fastify: the HTTP adapter with Fastify's plugins, JSON schemas and serialization.

/**
 * Buffers each file into `file.buffer`. The default storage engine, as in
 * multer.
 *
 * @publicApi
 */
export function memoryStorage() {
    return {
        _handleFile(_req, file, callback) {
            const chunks = [];
            const onData = (chunk) => chunks.push(chunk);
            const onError = (err) => {
                stopListening();
                callback(err);
            };
            const onEnd = () => {
                stopListening();
                const buffer = Buffer.concat(chunks);
                callback(null, { buffer, size: buffer.length });
            };
            // `@fastify/multipart` keeps every part's stream until the request
            // ends, and with it these listeners and the chunks they hold.
            const stopListening = () => file.stream.off('data', onData).off('error', onError).off('end', onEnd);
            file.stream.on('data', onData).once('error', onError).once('end', onEnd);
        },
        _removeFile(_req, file, callback) {
            delete file.buffer;
            callback(null);
        },
    };
}