Handle op:add for same path in patch

[omarismail94]

IMPORTANT: All PRs must be linked to an issue (except for extremely trivial and straightforward changes).

Fixes #2342

Description
When merging JSON patches:
* "replace" and "remove" operations from the second patch will overwrite any existing operations for the same path.
* "add" operations from the second patch will be added to the list of operations for that path, even if operations already exist for that path.

Alternative(s) considered
Have you considered any alternatives? And if so, why have you chosen the approach in this PR?

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Checklist

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• I have discussed my proposed solution with code owners in the linked issue(s) and we have agreed upon the general approach.
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[kelvin-ngure]

Edit: Below the *** was a concern had but I was wrong since the code is extracting the object from the list. And at the end, only the objects are inserted into the output array. So the structure during the reduction stays the same.

---

@omarismail94 since mergePatches is being called in a reduce function, the first time it runs, the parameters will receive strings with this sort of structure (the below are patch strings)

[{"op":"add","path":"/member/-","value":{"entity":{"reference":"Patient/dbe7936d-a1bc-4593-b219-025f34a8a8bf"}}}]
[{"op":"add","path":"/member/-","value":{"entity":{"reference":"Patient/e4ebe735-cbf5-4365-b8ad-0169466d51r9"}}}]

The output of the mergePatches function has the below structure since it is created from an Array Node (I use the word Patch String in place of the above objects)

[
Patch string,
Patch String,
]

Therefore, the next time the merge patches function is run (e.g when there are more than 2 LocalChange), the parameter for firstPatch will receive the correct data type but not the same structure. The first time, it was like this => [{}] but subsequent times it will be like this => [[{}], [{}]].

Will the op.get("path") still work? I assume that due to the nesting, path won't be recognized as a key. Thoughts?

[omarismail94]

Edit: Below the *** was a concern had but I was wrong since the code is extracting the object from the list. And at the end, only the objects are inserted into the output array. So the structure during the reduction stays the same.

@omarismail94 since mergePatches is being called in a reduce function, the first time it runs, the parameters will receive strings with this sort of structure (the below are patch strings)

[{"op":"add","path":"/member/-","value":{"entity":{"reference":"Patient/dbe7936d-a1bc-4593-b219-025f34a8a8bf"}}}] [{"op":"add","path":"/member/-","value":{"entity":{"reference":"Patient/e4ebe735-cbf5-4365-b8ad-0169466d51r9"}}}]

The output of the mergePatches function has the below structure since it is created from an Array Node (I use the word Patch String in place of the above objects)

[ Patch string, Patch String, ]

Therefore, the next time the merge patches function is run (e.g when there are more than 2 LocalChange), the parameter for firstPatch will receive the correct data type but not the same structure. The first time, it was like this => [{}] but subsequent times it will be like this => [[{}], [{}]].

Will the op.get("path") still work? I assume that due to the nesting, path won't be recognized as a key. Thoughts?

@kelvin-ngure thanks for clarifying! i assume the change fixes the issue you have then?

[kelvin-ngure]

@omarismail94 yes it looks like it will work for my issue

[MJ1998]

Is there any latest version of jsonpatch ?

I think for each activity the path generated should be unique and not activity/-

Update: We are using the latest library!
The idea to overwrite patches when op = replace / remove is scary to me. Let's say there are 2 activities added. and then 1 is updated. This would mean the patch will contain 2 adds and 1 replace. Will the path be same for all these 3 operations ? If yes then again we lose the second activity in the patch.

Can we add a test to check that on replace / remove the path is always different ?!