53 lines
1.4 KiB
Markdown
53 lines
1.4 KiB
Markdown
---
|
|
title: testing.assertEmpty() function
|
|
description: The testing.assertEmpty() function tests if an input stream is empty.
|
|
aliases:
|
|
- /influxdb/v2.0/reference/flux/functions/testing/assertempty/
|
|
- /influxdb/v2.0/reference/flux/stdlib/testing/assertempty/
|
|
- /influxdb/cloud/reference/flux/stdlib/testing/assertempty/
|
|
menu:
|
|
flux_0_x_ref:
|
|
name: testing.assertEmpty
|
|
parent: testing
|
|
weight: 301
|
|
flux/v0.x/tags: [tests, transformations]
|
|
introduced: 0.18.0
|
|
---
|
|
|
|
The `testing.assertEmpty()` function tests if an input stream is empty.
|
|
If not empty, the function returns an error.
|
|
|
|
```js
|
|
import "testing"
|
|
|
|
testing.assertEmpty()
|
|
```
|
|
|
|
_The `testing.assertEmpty()` function can be used to perform in-line tests in a query._
|
|
|
|
## Parameters
|
|
|
|
### tables {data-type="stream of tables"}
|
|
Input data.
|
|
Default is piped-forward data ([`<-`](/flux/v0.x/spec/expressions/#pipe-expressions)).
|
|
|
|
## Examples
|
|
|
|
#### Check if there is a difference between streams
|
|
This example uses the [`testing.diff()` function](/flux/v0.x/stdlib/testing/diff)
|
|
which outputs the diff for the two streams.
|
|
The `.testing.assertEmpty()` function checks to see if the diff is empty.
|
|
|
|
```js
|
|
import "testing"
|
|
|
|
got = from(bucket: "example-bucket")
|
|
|> range(start: -15m)
|
|
want = from(bucket: "backup_example-bucket")
|
|
|> range(start: -15m)
|
|
|
|
got
|
|
|> testing.diff(want: want)
|
|
|> testing.assertEmpty()
|
|
```
|