Jest: TypeError: Cannot read property 'fantasy-land/map'

I’m testing a React app with Jest and when some code hits a R.map() function, i get the following error:

TypeError: Cannot read property 'fantasy-land/map' of undefined

      at node_modules/ramda/src/internal/_dispatchable.js:29:23
      at Object.f2 [as map] (node_modules/ramda/src/internal/_curry2.js:25:16)

Looks related to the fantasy-land inclusion. Gotta say i don’t know how this can be fixed.

Ramda 0.24.1 Jest 20.0.4

If i comment the lines using those R.map() functions, error goes away.

[CrossEye]

Ramda has long taken a stand against hand-holding, assuming users would pass the correct types to its functions, and not checking this unless necessary. While I think that sentiment is slowly shifting, it’s not at all clear to me that Ramda is ready for that sort of argument validation.

[buzzdecafe]

There’s nowhere near enough context to offer any help here. I suspect that an undefined value is being passed as the second arg to map. But that is just a guess.