Ensure that // +optional params default to their zero value

[jedevc]

This means that we will always pass in an inline opts struct without the pointers, but we preserve the default value in the other cases.

So for example, given a *string parameter, if was optional and not set, we should default to nil, not a pointer to an empty string (which was the previous behaviour).

Tests for this as well, and also handles a weird and edgy case where we could maybe have an *Optional.

Original bug reported by @aweris (thanks thanks!!):

// External workflow file to run.
// +optional=true
workflowFile *File,

as parameter does not return nil. Instead returns empty object which by passes if workflowfile != nil check

The original use for findOptsAccessPattern was for handling inline opts structs more easily, but we should only apply it for those cases, and not across the board, since it removes our ability to use the proper default zero value.

Looking forward to removing the inline opts structs maybe at some point? Lots of code to simplify if we do!

[sipsma]

@jedevc saw there were legit test failures, it was a quick fix so I just pushed that now so I can approve and everything will be ready for the release tomorrow: a7f51c1

Basically, the test cases involving this function were failing:

func (m *Minimal) EchoOptionalPointer(msg **Optional[**string]) string {
	v, ok := (*msg).Get()
	if !ok {
		v = ptr(ptr("default"))
	}
	return m.Echo(**v)
}

specifically due to a nil panic on (*msg).

That was due to the fact that the change resulted in any *Optional or **Optional to itself be nil when the value wasn't provided, which didn't feel correct besides causing that test to fail.

The new generated code that had the problem looked like:

var msg **Optional[**string]
if inputArgs["msg"] != nil {
  err = json.Unmarshal([]byte(inputArgs["msg"]), &msg)
  if err != nil {
    fmt.Println(err.Error())
    os.Exit(2)
  }
}
return (*Minimal).EchoOptionalPointer(&parent, msg), nil

After the commit I pushed that particular case of an **Optional wrapped arg goes back to the way it was before:

var msg Optional[**string]
if inputArgs["msg"] != nil {
  err = json.Unmarshal([]byte(inputArgs["msg"]), &msg)
  if err != nil {
    fmt.Println(err.Error())
    os.Exit(2)
  }
}
return (*Minimal).EchoOptionalPointer(&parent, ptr(ptr(msg))), nil

Agree that it would be nice to remove support for the inline struct soon (next release?) and maybe also consider removing Optional sometime too if the new //+optional works out as expected.

[jedevc]

Ah thanks @sipsma!