spdx3: element_writer: switch from tab characters to two spaces

[stanislaw]

Hello everyone,

This is my first issue to this repository. I am new to SPDX and apologize for possible misunderstanding of the intentions behind the code I am modifying.

I am integrating the SPDX 3.0 export to the StrictDoc tool, see strictdoc-project/strictdoc#1541.

The starting point for this issue is the fact that the Creation Information block is suddenly nested with a tab character when I try to populate an spdx3.*.SpdxDocument and write to a string buffer. My IDE is set up to ignore tab characters, so the output is displayed as if the indentation level was 1 character wide.

In this MR, the creation info is unindented, and a test is added to demonstrate the behavior I would expect to see.

[maxhbr]

I think that the indentation was intentional. As sub-structures within an object are also come with indentation in other places. Maybe we could indent with spaces instead of \t to be more stable.

[stanislaw]

I think that the indentation was intentional. As sub-structures within an object are also come with indentation in other places. Maybe we could indent with spaces instead of \t to be more stable.

This makes sense. Definitely it would make sense to replace \t with \n\n for example.

An extra thought regarding the indentation of creation info: in YAML things are indented when there is a key that bundles together indented content. On the screenshot above, the role of a "key" is played by a comment Creation Information which to me looks confusing visually because it is just a comment and on actual key.

In YAML this would look like:

creation_info:
  spec_version: ...
  ...

I am ready to both engage or disengage, so how could we proceed? Is it worth to use this MR for replacing \t with \n\n everywhere?

[maxhbr]

we would appreciate if you would make the changes to spaces. But you could also just put it into a new issue, if you want.

[stanislaw]

we would appreciate if you would make the changes to spaces. But you could also just put it into a new issue, if you want.

Please check the change I've made.

[maxhbr]

LGTM