node-postgres/packages/pg-native/test/async-workflow.js

const Client = require('../')
const ok = require('okay')
const assert = require('assert')
const concat = require('concat-stream')

describe('async workflow', function () {
  before(function (done) {
    this.client = new Client()
    this.client.connect(done)
  })

  const echoParams = function (params, cb) {
    this.client.query(
      'SELECT $1::text as first, $2::text as second',
      params,
      ok(cb, function (rows) {
        checkParams(params, rows)
        cb(null, rows)
      })
    )
  }

  const checkParams = function (params, rows) {
    assert.equal(rows.length, 1)
    assert.equal(rows[0].first, params[0])
    assert.equal(rows[0].second, params[1])
  }

  it('sends async query', function (done) {
    const params = ['one', 'two']
    echoParams.call(this, params, done)
  })

  it('sends multiple async queries', function (done) {
    const self = this
    const params = ['bang', 'boom']
    echoParams.call(
      this,
      params,
      ok(done, function (rows) {
        echoParams.call(self, params, done)
      })
    )
  })

  it('sends an async query, copies in, copies out, and sends another query', function (done) {
    const self = this
    this.client.querySync('CREATE TEMP TABLE test(name text, age int)')
    this.client.query(
      "INSERT INTO test(name, age) VALUES('brian', 32)",
      ok(done, function () {
        self.client.querySync('COPY test FROM stdin')
        const input = self.client.getCopyStream()
        input.write(Buffer.from('Aaron\t30\n', 'utf8'))
        input.end(function () {
          self.client.query(
            'SELECT COUNT(*) FROM test',
            ok(done, function (rows) {
              assert.equal(rows.length, 1)
              self.client.query(
                'COPY test TO stdout',
                ok(done, function () {
                  const output = self.client.getCopyStream()

                  // pump the stream
                  output.read()
                  output.pipe(
                    concat(function (res) {
                      done()
                    })
                  )
                })
              )
            })
          )
        })
      })
    )
  })
})