docs-v2/content/v2.0/reference/flux/functions/testing/assertempty.md

title	description	menu
testing.assertEmpty() function	The testing.assertEmpty() function tests if an input stream is empty.	v2_0_ref name parent weight testing.assertEmpty Testing 301

The testing.assertEmpty() function tests if an input stream is empty. If not empty, the function outputs an error.

Function type: Test

import "testing"

testing.assertEmpty()

The testing.assertEmpty() function can be used to perform in-line tests in a query.

Examples

Check if there is a difference between streams

This example uses the diff() function which outputs the diff for the two streams. The .testing.assertEmpty() function checks to see if the diff is empty.

import "testing"

got = from(bucket: "telegraf/autogen")
  |> range(start: -15m)
want = from(bucket: "backup_telegraf/autogen")
  |> range(start: -15m)
got
  |> diff(want: want)
  |> testing.assertEmpty()