cmd/cue: trim default + optional interaction

[vikstrous2]

What version of CUE are you using (cue version)?

$ cue version v0.3.0-beta.4 linux/amd64

Does this issue reproduce with the latest release?

yes

What did you do?

tmp.cue

#maybeString: {ip?: string}
something: ip: *"default" | string
something: #maybeString

cue trim tmp.cue

What did you expect to see?

I don't think this looks like something that can be trimmed, so probably no change.

What did you see instead?

  {
      #maybeString: close({
        ip?: string
      })
      something: {
-         ip: (*"default" | string) & string
+         ip?: string
      }
  }
Aborting trim, output differs after trimming. This is a bug! Use -i to force trim.
You can file a bug here: https://github.com/cuelang/cue/issues/new?assignees=&labels=NeedsInvestigation&template=bug_report.md&title=

[myitcv]

Confirmed with 760aa11:

cp main.cue.golden main.cue
exec cue trim ./...
cmp main.cue main.cue.golden

-- main.cue.golden --
package main

#maybeString: {ip?: string}
something: ip: *"default" | string
something: #maybeString

Marking as a feature request because trim needs to be coded for each case.

[cueckoo]

This issue has been migrated to cue-lang/cue#759.

For more details about CUE's migration to a new home, please see cue-lang/cue#1078.