docs-v2/content/flux/v0/stdlib/testing/assertempty.md

title	description	menu	weight	flux/v0/tags	introduced
testing.assertEmpty() function	`testing.assertEmpty()` tests if an input stream is empty. If not empty, the function returns an error.	flux_v0_ref name parent identifier testing.assertEmpty testing testing/assertEmpty	101	tests	0.18.0

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

assertEmpty can be used to perform in-line tests in a query.

Function type signature

(<-tables: stream[A]) => stream[A]

{{% caption %}} For more information, see Function type signatures. {{% /caption %}}

Parameters

tables

Input data. Default is piped-forward data (<-).

Examples

Check if there is a difference between streams

This example uses testing.diff() to output the difference between two streams of tables. testing.assertEmpty() checks to see if the difference is empty.

import "sampledata"
import "testing"

want = sampledata.int()
got = sampledata.float() |> toInt()

got
    |> testing.diff(want: want)
    |> testing.assertEmpty()