JSX4: Unhelpful error message in case of duplicate prop

[cknitt]

If the user accidentally adds the same prop twice (which is easy to overlook in case of a big number of props), they get the unhelpful error message:

  A type parameter occurs several times

with no LoC information.

Example:

@react.component
let make = (
  ~someProp: bool,
  // ... more props ...
  ~someProp: bool,
) => React.null

[cknitt]

(Same for external bindings where we actually experienced the problem in practice:)

@module("some-module") @react.component
external make: (
  ~someProp: bool,
  // ... more props ...
  ~someProp: bool,
) => React.element = "default"

[mununki]

Thanks for opening the issue. Looking into it.

[mununki]

@cknitt Can you try this fix #5937 ?

[cknitt]

Sorry, forgot to answer here. I confirm that this is fixed now.