How can i rewrite type checks of object props in Ramda

Question

I'm trying put my head around how rewrite the following TS code using Ramda:

const uniqueIdentifierRegEx = /.*id.*|.*name.*|.*key.*/i;
const uniqueIdentifierPropTypes = ['string', 'number', 'bigint'];

const findUniqueProp = (obj: any) => Object.keys(obj)
    .filter(prop => uniqueIdentifierPropTypes.includes(typeof obj[prop]))
    .find(prop => uniqueIdentifierRegEx.test(prop));

I ended up with something like this, but it does not really work:

const data = {a:1, name: 'name', nameFn: () => {}};
const uniqueIdentifierRegEx = /.*id.*|.*name.*|.*key.*/i;
const uniqueIdentifierPropTypes = ['string', 'number', 'bigint'];

const filterPred = curry((obj, prop_, types) => includes(type(prop(prop_, obj)), types));
const findProd = curry((prop_, regEx) => regEx.test(prop))

const findUniqueProp = (obj, types, regEx) =>
   pipe(
     keys,
     filter(filterPred(types)),
     find(findProd(regEx))
   )(obj)

findUniqueProp(data, uniqueIdentifierPropTypes, uniqueIdentifierRegEx)

Potentially, pickBy can be used to filter out props... but Im lost. Please help to connect the dots.

Answer 1

To transform an object properties by key and value, it's often easiest to convert the object to an array of [key, value] pairs via R.toPairs , transform the pairs (using R.filter in this case), and then convert back to an object using R.fromPairs .

To filter the pairs, I'm using R.where to check the key (index 0 in the pair), and the value (index 1 in the pair) by wrapping the RegExp, and the array of permitted types in functions.

Note: R.type returns the types in pascal case - String , Number , and BigInt .

 const { test, pipe, type, flip, includes, toPairs, filter, where, fromPairs } = R const uniqueIdentifierRegEx = test(/.*id.*|.*name.*|.*key.*/i) // test if string matches regexp const uniqueIdentifierPropTypes = pipe(type, flip(includes)(['String', 'Number', 'BigInt'])) // test if the type of the value is in the array const fn = pipe( toPairs, // convert to [key, value] pairs filter(where([ // filter and use where to check the key (0) and the value (1) uniqueIdentifierRegEx, uniqueIdentifierPropTypes ])), fromPairs // convert back to object ) const data = {a: 1, name: 'name', nameFn: () => {}} const result = fn(data) console.log(result)

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