docs-v2/content/flux/v0.x/stdlib/testing/diff.md

title	description	aliases	menu	weight	flux/v0.x/tags	introduced
testing.diff() function	The testing.diff() function produces a diff between two streams.	/influxdb/v2.0/reference/flux/functions/testing/diff/ /influxdb/v2.0/reference/flux/stdlib/testing/diff/ /influxdb/cloud/reference/flux/stdlib/testing/diff/	flux_0_x_ref name parent testing.diff testing	301	tests transformations	0.18.0

The testing.diff() function produces a diff between two streams.

import "testing"

testing.diff(
    got: stream2,
    want: stream1,
    epsilon: 0.000001,
    nansEqual: false,
    verbose: false,
)

It matches tables from each stream with the same group keys. For each matched table, it produces a diff. Any added or removed rows are added to the table as a row. An additional string column with the name diff is created and contains a - if the row was present in the got table and not in the want table or + if the opposite is true.

The diff function is guaranteed to emit at least one row if the tables are different and no rows if the tables are the same. The exact diff produced may change.

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

Parameters

got

Stream containing data to test. Default is piped-forward data (<-).

want

Stream that contains the expected data to test against.

epsilon

Specifies how far apart two float values can be, but still considered equal. Default is 0.000001.

nansEqual

Consider NaN float values equal. Default is false.

verbose

Include detailed differences in output. Default is false.

Examples

Diff separate streams

import "testing"

want = from(bucket: "backup-example-bucket")
    |> range(start: -5m)
got = from(bucket: "example-bucket")
    |> range(start: -5m)

testing.diff(got: got, want: want)

Inline diff

iimport "testing"

want = from(bucket: "backup-example-bucket") |> range(start: -5m)

from(bucket: "example-bucket")
    |> range(start: -5m)
    |> testing.diff(want: want)