@sap/cds/libx/odata/middleware/parse.js

SAP Cloud Application Programming Model - CDS for Node.js

const cds = require('../../../lib')
const odata = require('../index')
const bodyParser4 = require('../../http/body-parser')
const { isStream } = require('../utils')

/**
 * @param {import('../ODataAdapter')} adapter
 * the adapter instance in which this middleware is used
 */
module.exports = adapter => {
  const { service } = adapter
  const bodyParser = bodyParser4(adapter)

  /**
   * @type {import('express').RequestHandler}
   */
  return function parse_odata_url(req, res, next) {
    if (req.path !== '/$batch')
      req._query ??= odata.parse(req.url, {
        service,
        baseUrl: req.baseUrl,
        strict: true,
        protocol: 'odata'
      })

    switch (req.method) {
      case 'POST':
        if (req.get('content-type')?.includes('multipart/mixed')) return next()
        if (req.get('content-type')?.includes('application/json')) break
        if ((req.get('content-length') || 0) == 0)
          break // works for '0', 0, and undefined
        else throw cds.error(415)
      case 'PUT':
        if (isStream(req._query)) {
          req.body = { value: req }
          return next()
        }
      // falls through
      case 'PATCH':
        if (req._query?.SELECT?.from.ref?.slice(-1)[0]?.operation)
          throw cds.error(405, `Method ${req.method} not allowed for calling custom actions`)
        if (req.get('content-type')?.includes('application/json'))
          if (req.get('content-length') == 0) throw cds.error(400, 'Expected non-empty body')
          else break
        else throw cds.error(415)
    }
    return bodyParser(req, res, next)
  }
}