Given a list of objects and list of keys from them, find the longest length

maxPropLenList.js

const data = [
  { label: 'first', val: 'gold-like' },
  { label: 'second', val: 'silver-esque' },
  { label: 'third', val: 'bronz-ish' },
];

const propLen = (propName) => compose(
  length,
  propOr('', propName)
);

const maxList = reduce(max, 0);

const maxPropLen = (propList) => compose(
  maxList,
  juxt(map(propLen, propList))
);

const maxPropLenList = (propList) => compose(
  maxList,
  map(maxPropLen(propList))
);

const maxPropLenList2 = (propList) => reduce(
  (acc, item) => max(
    acc,
    maxPropLen(propList)(item)
  ),
  0
)

maxPropLenList2(['label', 'val'])(data);