Pre-request script to prepare header for LNMarket

pre-request.js

const requestTimestamp = new Date().getTime()
const requestPath = `/${pm.request.url.path.join('/')}`
const requestMethod = pm.request.method
let requestParams = ''

if (requestMethod.match(/^(GET|DELETE)$/)) {
  requestParams = new URLSearchParams(pm.request.url.query.all()).toString()
} else {
  requestParams = pm.request.body.raw 
    ? JSON.stringify(JSON.parse(pm.request.body.raw))
    : ''
}

// prepare signature
// const signature = createHmac('sha256', secret).update(`${timestamp}${method}${path}${params}`).digest('base64')
const message = requestTimestamp + requestMethod + requestPath + requestParams
const secret = pm.collectionVariables.get('LNM-ACCESS-SECRET')
const hash = CryptoJS.algo.HMAC.create(CryptoJS.algo.SHA256, secret)
  .update(message)
  .finalize()
const signature = CryptoJS.enc.Base64.stringify(hash)

// set dynamic variable
pm.collectionVariables.set("LNM-ACCESS-TIMESTAMP", requestTimestamp)
pm.collectionVariables.set("LNM-ACCESS-SIGNATURE", signature)

// set default header 
pm.request.headers.add('LNM-ACCESS-KEY: {{LNM-ACCESS-KEY}}')
pm.request.headers.add('LNM-ACCESS-PASSPHRASE: {{LNM-ACCESS-PASSPHRASE}}')
pm.request.headers.add('LNM-ACCESS-SIGNATURE: {{LNM-ACCESS-SIGNATURE}}')
pm.request.headers.add('LNM-ACCESS-TIMESTAMP: {{LNM-ACCESS-TIMESTAMP}}')

// set content type
pm.request.headers.add('Content-Type: application/json')