Accessing optional inputs should return null rather than resulting in an error about kestra

[loicmathieu]

I run the first example and it show this exception: Missing variable: 'my_input' on '{{ inputs.my_input }}' at line 1 which is expected ad the variable my_input didn't exist. If you have the exception with the variable inputs it means you are not on the latest version of Kestra.

For the second point:

In the above flow, inputs is an empty map {} as if there would be no inputs, even though there is one, even explicitly set to null.

null means no input, one possibility would be to switch run context variables serialization to ALWAYS (inputs will be included in this list) so variables set to null would be included.

[anna-geller]

Let's explore that option with ALWAYS or some alternatives then. The goal is for both examples from the issue body to work in 0.17

[anna-geller]

great work @loicmathieu <3 I thought this would be way more complex, thx a lot!

this one also works as expected:

id: my_flow
namespace: dev

inputs:
  - id: my_input
    type: STRING
    defaults: null
    required: false

tasks:
  - id: check
    type: io.kestra.plugin.core.flow.If
    condition: "{{ inputs.my_input is null }}"
    then: 
      - id: isnull
        type: io.kestra.plugin.core.log.Log
        message: it's a null
    else:
      - id: isnotnull
        type: io.kestra.plugin.core.log.Log
        message: not null

seems like nothing left to discuss regarding serialization so I'll cancel that meeting