fix: add deploy-related environment variables to local builds

[ehmicky]

Fixes #3904

This PR builds on top of #3931 which was created by @lukasholzer a few months ago to solve this issue.

This adds dummy values for 4 environment variables in local builds (not production builds): DEPLOY_ID, BUILD_ID, DEPLOY_URL and DEPLOY_PRIME_URL.

This is a rather small change from a production code standpoint. However, it updates a high amount of test snapshots, but those changes are all identical, essentially just adding those new default values to the test snapshots.

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[ehmicky]

In local builds, this default value for the site name is used by the DEPLOY_URL and DEPLOY_PRIME_URL environment variables, but intentionally not by the SITE_NAME environment variable. This is to be consistent with SITE_ID which is also unavailable when the authentication token or siteId has not been provided.

Please note this situation is an edge case, since it cannot happen in neither production nor CLI builds, only when @netlify/build is called programmatically (which at the moment is mostly only used in @netlify/build automated tests).

[erezrokah]

Thanks @ehmicky, the code looks great.

I added 2 comments on possible edge cases to handle.

[erezrokah]

I wonder if NETLIFY_DEFAULT_DOMAIN is still used when a user has a custom domain configured.
What will be the host for DEPLOY_PRIME_URL and DEPLOY_URL in that case?
If not, we might be able to take them from the siteInfo (if it is available)

[ehmicky]

Good question. Yes, .netlify.app is still used even with a custom domain, but only for DEPLOY_URL and DEPLOY_PRIME_URL, not for URL. This is documented as such, but I also confirmed this with a manual test on my test site which uses a custom domain (see build logs).

[erezrokah]

Where do we get branch and deployId from?

branch might not be available if running from a non git folder

[ehmicky]

deployId is taken from:

build/packages/config/src/options/main.js

Line 47 in e118a5c

deployId: combinedEnv.DEPLOY_ID,

Before this PR, it was set either the @netlify/config flag deployId (which we use in production) or the DEPLOY_ID environment variable. With this PR, it also defaults to 0 for CLI and programmatic builds.

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branch is taken from:

https://github.com/netlify/build/blob/main/packages/config/src/options/branch.js#L3-L9

It has a default value when used in a non-git environment.