Include changelog history for each operator on their doc page

[martinsik]

Please check those that apply

• typo
• documentation doesn't exist
• documentation needs clarification
• error(s) in example
• needs example

Description Of The Issue

I personally find it increasingly difficult to keep track of what operator behavior has changed in what version and I always have to search through CHANGELOG.md.

So it made me thinking that the API documentation for each operator could include a section with all changes ordered by RxJS version (ideally with links to relevant issues and PRs). CHANGELOG.md already has each line starting with scope so this could work automatically by "just" creating another dgeni processor.

[imcotton]

This would be great, reminds me what Node.js been doing, e.g. fs.readFile (click the History toggle)

[martinsik]

@imcotton That's exactly what I meant.

[niklas-wortmann]

Oh that is a very cool idea. I will think about it and add some of my thoughts later on!

[martinsik]

Maybe related to this #5128

[BioPhoton]

Hi @martinsik!

@ deprecations can be important from 2 perspectives:

• A) I used an operator back then and now it is not working how I used it. I want to have a history of changes for the operator in question
• B) I want to upgrade RxJS and get a complete list of changes from my current to the version in question

I suggest a simple data view change in the MigrationTimeline.

You can switch from group by version to group by subject .e.g. operators.

This would

• help A)
• help B)
• don't bloat the documentation page even more. (Actual the deprecated overloads make it noisy)