feat(helpers)!: stricter checking for function signature passed to multiple

[pomali]

faker.helpers.multiple() supports using mapFn like in Array.from(), but type signature of function didn't match, PR fixes this and adds test for this case

(but since it changes declared interface I chose feat instead of fix as semantic type)

[xDivisionByZerox]

I'm not sure if this fits the use case of faker.helpers.multiple 🤔

If you require the parameters of the mal function, you are most likely doing some static value generation.

I need some time to think about this in more detail.

[pomali]

Yes, usecase here is generating two sets of objects with matching ids, so I can "join" them later.
Eg.

interface School { locationId: number }
interface Location { id: number }

I could create an function with no arguments that simulates this behavior, but it seemed busywork since underlying code already supports it.

I am using it in place without shared state (in mock service worker in two different endpoints)

[ST-DDT]

The index parameter might be useful when generating a list of entries that should have sequential ids.

However I would like to block this until v9.0 development commences, because then the method might get a new parameter (ref fakerCore) anyway.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.56%. Comparing base (9348138) to head (529aac6).

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #2563      +/-   ##
==========================================
- Coverage   99.57%   99.56%   -0.02%     
==========================================
  Files        2846     2846              
  Lines      248715   248717       +2     
  Branches      655     1011     +356     
==========================================
- Hits       247669   247634      -35     
- Misses       1017     1083      +66     
+ Partials       29        0      -29     

Files	Coverage Δ
src/modules/helpers/index.ts	98.82% <100.00%> (+<0.01%)	⬆️

... and 30 files with indirect coverage changes

[ST-DDT]

Sorry for the delay in feedback.
Could you please update this PR with the latest suggestions?

[pomali]

Sorry for the delay in feedback. Could you please update this PR with the latest suggestions?

No problem, sorry for mine delay. Updated.

[ST-DDT]

Could you please fix the broken tests and examples?
The tests were already broken due to the wrong typing of the method before, but now the method actually requires proper types and thus the bad usage actually shows up.

firstName -> () -> firstName()

[ST-DDT]

Please also enable allow edits by maintainers on this PR so we can update it ourself to the latest commits on next.

[rtm-ctrlz]

GitHub still asking me for review :)

In my opinion this change should be accepted and marked as breaking change.

In most cases this change should not lead to breaks, but it worth a notice.

[Shinigami92]

Really good migration guide 👍