Exclude some keys during snapshot testing

[denisbrainyyack]

During the snapshot testing, we want to ignore some document keys that are important during the deployment of the chart, but are not important during development. For example, the key helm.sh/chart , which is updated every time we update the version field in Chart.yaml.

It would be great if it were possible to specify such a configuration:

templates:
  - templates/serviceaccount.yaml
tests:
  - it: Manifests should match snapshot
    asserts:
      - matchSnapshot:
          ignoreKeys:
            - "helm.sh/chart"

Expecting that in this case the snapshot would not contain keys with that name.

Manifests should match snapshot:
  1: |
    apiVersion: v1
    kind: ServiceAccount
    metadata:
      labels:
        app.kubernetes.io/instance: RELEASE-NAME
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/name: helm-unittest-snapshot-testing
        app.kubernetes.io/version: 1.16.0
        # Commented-out lines should not be generated when using the `ignoreKeys` settings.
        # helm.sh/chart: helm-unittest-snapshot-testing-0.1.0
      name: RELEASE-NAME-helm-unittest-snapshot-testing

[quintush]

Hello @denisbrainyyack,

I will look into this.
With the current set it is possible to set a path to generate the snapshot.
With the path it is not required to validate the whole output.

Greetings,
@quintush

[denisbrainyyack]

Hello @quintush,

I'll add some context about our case.

We have a library chart and several application charts that we build based on the library chart. When developing a library chart, we do not use snapshot testing, but for application charts we use snapshot testing to control changes in default values, dependency versions, etc. Some application charts may consist of several sub-charts and that in total gives more than 50 documents.

It looks like using the path key is not suitable in this case.

I would like to take this opportunity to thank you for your great work!

[michael-todorovic]

Until we can have this feat, I did a small workaround in _helpers.tpl

{{- define "mychart.version" -}}
{{- printf "%s-%s" .Chart.Name (.Values.unittestChartVersion | default .Chart.Version) | replace "+" "_" | trunc 63 | trimSuffix "-" -}}
{{- end -}}

and then I use it in my annotation:

helm.sh/chart: {{ include "mychart.version" . }}

Finally, in the values I give to unittest, I have

# this is only to make snapshot work
unittestChartVersion: 0.0.1-unittest

[begemotik]

Alternatively, you might simply implement some "switch variable", for instance .Values.unitTest == false (by default). If set to true it should prevent rendering dynamic entities like app.kubernetes.io/version, checksum/config, checksum/secret, etc.