How to combine multiple commit diffs?

[ZheNing Hu <adlternative@gmail.com>]

Hi everyone,

Our company wants to design a "small-batch" code review feature.
Simply put, this "small-batch" means being able to treat multiple
related commits within a MergeRequest as an independent "small" code
review.

Let me give you an example: We have five commits: A1, B, A2, C, A3.
Among them, A1, A2, and A3 are multiple commits for the same feature.
So when the user selects these commits, the page will return a
"combine diff" that combines them together.

A1       B A2 A3 C
*--------*----*-----*-------* (branch)
 \ A1'        \ A2'  \ A3'
  *------------*------*------- (small branch code review)

This may seem similar to cherry-picking a few commits from a pile of
commits, but in fact, we do not expect to actually perform
cherry-picking.

Do you have any suggestions on how we can merge a few commits together
and display the diff? The only reference we have is the non-open
source platform, JetBrains Space CodeReview, they support selecting
multiple commits for CodeReview. [1], .

[1]: https://www.jetbrains.com/help/space/review-code.html#code-review-example

Thanks,
--
ZheNing Hu