test.js

var el = {}

var props = Object.keys(el)

propes.forEach(function (p) {
  el[p] = function(v) {
    
  }
})

//----------------------------

function createGetter(p, el) {
  return function (v) {
    // do something with el[p]
  }
}

for (var p in el) {
  el[p] = createGetter(p, el)
}