feat: Deploy preview with details which data is going to be updated for each file changed (similar to terraform plan command)

[sir-alex]

What problem does this feature solve?

Before deploying changes to the cloud, it’s beneficial to preview what changes will be submitted. This is similar to the terraform plan command.

While there is a preview flag for npx checkly deploy -p, it only provides a list of logicalIds without showing the exact content of the changes. Without these details, it becomes difficult to understand what will be updated in the cloud, as demonstrated in the image below:

Ideally, a standalone command like npx checkly preview would be available for previews, similar to:

terraform plan
cdk diff
pulumi preview

How would you implement this feature?

Proposed Implementation Steps:

1. Retrieve the current data from the server via API.

2. Gather the data to be sent to the API.

3. Compare the differences and display them in the CLI in a format that clearly shows the current values and the proposed updates for easy understanding.

[sorccu]

Hi @sir-alex, yes that's a great idea and something we have planned already. I cannot provide an estimate right now, but it is something that we will be working on in the near future.

[sir-alex]

Hi @sir-alex, yes that's a great idea and something we have planned already. I cannot provide an estimate right now, but it is something that we will be working on in the near future.

Hi @sorccu
I have proposed my solution in this PR #994
I tried to describe as more details as possible

Please have a look