Unexpected anchor behaviour when using functions

[groundnuty]

What steps did you take:

Input:

#@ def group_alpha():
name: alpha
#@ end
groups: &all_groups
  - #@ group_alpha()
foo:
  groups: *all_groups

Result:

groups:
- null
foo:
  groups:
  - name: alpha

Expected:

groups:
- alpha
foo:
  groups:
  - name: alpha

Expected according to limitations

groups:
- alpha
foo:
  groups:
  - null

Interactive reproduction from gist.

Anything else you would like to add:
Please explain this unexpected behaviour, as it's not consistent with #172 or #186

Environment:

• ytt version 0.36.0
• macos 10.14 (18A391)

[cppforlife]

hey @groundnuty, as you found this is one of the known limitations (https://carvel.dev/ytt/docs/latest/known-limitations/); however, we should have probably made more clear that results are "undefined" (instead of providing some example). currently (and that may change) last node that splats the anchor would receive data. for your example:

#@ def group_alpha():
name: alpha
#@ end
groups: &all_groups
  - #@ group_alpha()
foo:
  groups: *all_groups  <--- this will be nil
  foo: *all_groups  <--- this will actually contain it

tldr -- we should improve docs to clarify that you should not rely on this behaviour.

[Rajdeep1311]

I want to get involved in this project can anybody please help? how to get started?