Does terratest support snapshot based assertion?

[jguionnet]

helm-unittest as a great feature called snapshot testing.

Sometimes you may just want to check that the rendered manifest did not change between helm package version without every details asserted.

With Terratest, we could add a feature in helm module to support that. For example, we could

• Add a set of helper functions, like the UnmarshalK8SYaml functions.
  • one function would create/refresh the local snapshot
  • one function would diff the manifest generated by the test against the local snapshot. It would return false if they are different and would have an option to display the difference in that case.

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Tracked in ticket #110569

[gitsstewart]

@jguionnet We will take a look at your suggestion and see if it fits on our current priority list for terratest. In the meantime, we welcome you to submit a pull request for the community to review.

[denis256]

Hello,
yes, snapshot testing functions will be helpful, looking forward for PRs :)

[jguionnet]

Created an issue for it gruntwork-io/terratest#1377

[so0k]

looks like this was closed for k8s yaml with gruntwork-io/terratest#1378

for reference of future visitors/googlers, golang has many snapshot testing libraries for example:

• github.com/google/go-cmp/cmp
• github.com/gkampitakis/go-snaps

both work great, in my case I wanted to be able to template and test a fragment, so I built some helpers

https://github.com/envtio/base/blob/v0.0.7/integ/aws/iam/helpers_test.go#L32

However, as I try to match the Integration testing behaviour of AWS CDK, I created JMESPath based regex assertions instead

for example:

• https://github.com/envtio/base/blob/v0.0.7/integ/aws/edge/edge_test.go#L70-L93
• https://github.com/envtio/base/blob/v0.0.7/integ/aws/compute/function_test.go#L89-L106

Not sure what's the best place to discuss if there's interest in upstreaming some of this functionality, but I felt it was related to snapshot testing and assertions, and this was the only discussion thread with recent activity on terratest.

EDIT 3: As I was unaware there was pre-existing work for snapshot testing in terratest (maybe it should be outside of helm and more under a module of its own?

I'll have a look at the existing libraries used instead

• github.com/gonvenience/ytbx
• github.com/homeport/dyff/pkg/dyff