Out of order response from Node.js response streaming - provided by Doug Moscrop and Ampt

lambda_streaming_out_of_order.js

const MAX_LINES = 30000
export const handler = awslambda.streamifyResponse(async (_event, responseStream, _context) => {
    await new Promise((resolve, _reject) => {
        let i = 1
        responseStream.on('error', (err) => {
            console.error('error:', err)
            _reject(err)
        })
        responseStream.on('close', () => {
            console.log('closed')
        })
        responseStream.on('finish', () => {
            console.log('finished')
            resolve()
        })
        write()

        function write() {
            let ok = true
            do {
                if (i === MAX_LINES) {
                    responseStream.end(`This is line ${i}\n`)
                } else {
                    ok = responseStream.write(`This is line ${i}\n`)
                }
                i++
            } while (i <= MAX_LINES && ok)
            if (i <= MAX_LINES) {
                console.log('buffer full - waiting for drain')
                responseStream.once('drain', write)
            }
        }
    })
})