Javascript script optimization with map/reduce/filter

Question

Here is my problem, I receive these kind of json data and I don't know in advance the keys (unknownProperty#) but the different objects in this data array have the same keys. What I need to do is to calculate the number of each level of alert (these levels are fixed). Here is what my end result should look like

var result = { unknownProperty1: { unknown: 0, ok: 2, warning: 0, ko: 1 },
  unknownProperty2: { unknown: 0, ok: 0, warning: 2, ko: 1 },
  unknownProperty3: { unknown: 3, ok: 0, warning: 0, ko: 0 },
  unknownProperty4: { unknown: 0, ok: 0, warning: 3, ko: 0 },
  unknownProperty5: { unknown: 0, ok: 0, warning: 2, ko: 1 } }

My script is working but I would like to know if there is any way to optimize/clean it with map/reduce/filter javascript function

const data = [
  {
    unknownProperty1: { alert: "ok", unusedItem1: "something" },
    unknownProperty2: { alert: "warning", unusedItem1: "something" },
    unknownProperty3: { alert: "unknown", unusedItem1: "something" },
    unknownProperty4: { alert: "warning", unusedItem1: "something" },
    unknownProperty5: { alert: "ko", unusedItem1: "something" }
  },
  {
    unknownProperty1: { alert: "ok", unusedItem1: "something" },
    unknownProperty2: { alert: "warning", unusedItem1: "something" },
    unknownProperty3: { alert: "unknown", unusedItem1: "something" },
    unknownProperty4: { alert: "warning", unusedItem1: "something" },
    unknownProperty5: { alert: "warning", unusedItem1: "something" }
  },
  {
    unknownProperty1: { alert: "ko", unusedItem1: "something" },
    unknownProperty2: { alert: "ko", unusedItem1: "something" },
    unknownProperty3: { alert: "unknown", unusedItem1: "something" },
    unknownProperty4: { alert: "warning", unusedItem1: "something" },
    unknownProperty5: { alert: "warning", unusedItem1: "something" }
  }
];

var result = new Object();
var dataKeys = data.map(function(element) {
  return Object.keys(element);
});
dataKeys[0].map(function(element) {
  result[element] = { unknown: 0, ok: 0, warning: 0, ko: 0 };
});
//At this point the result is like what we expect but no calculation has been made yet

//We then increment the right values
data.map(function(element) {
  for (var prop in element) {
    if (Object.prototype.hasOwnProperty.call(element, prop)) {
      // element correspond to the current object
      // prop corresponds to the name of the key, for example 'unknownProperty1'
      switch (element[prop].alert) {
        case "ok":
          result[prop].ok++;
          break;
        case "warning":
          result[prop].warning++;
          break;
        case "unknown":
          result[prop].unknown++;
          break;
        case "ko":
          result[prop].ko++;
          break;

        default:
          break;
      }
    }
  }
});
console.log(result);

Answer 1

Reduce into an object indexed by the unknownProperty_ keys, iterating over the inner objects and creating the appropriate key on the accumulator if it doesn't exist yet, and setting its value to { unknown: 0, ok: 0, warning: 0, ko: 0 }. Then, on each iteration over an unknownProperty object, just extract the alert and increment the a[key][alert]:

const data = [
  {
    unknownProperty1: { alert: "ok", unusedItem1: "something" },
    unknownProperty2: { alert: "warning", unusedItem1: "something" },
    unknownProperty3: { alert: "unknown", unusedItem1: "something" },
    unknownProperty4: { alert: "warning", unusedItem1: "something" },
    unknownProperty5: { alert: "ko", unusedItem1: "something" }
  },
  {
    unknownProperty1: { alert: "ok", unusedItem1: "something" },
    unknownProperty2: { alert: "warning", unusedItem1: "something" },
    unknownProperty3: { alert: "unknown", unusedItem1: "something" },
    unknownProperty4: { alert: "warning", unusedItem1: "something" },
    unknownProperty5: { alert: "warning", unusedItem1: "something" }
  },
  {
    unknownProperty1: { alert: "ko", unusedItem1: "something" },
    unknownProperty2: { alert: "ko", unusedItem1: "something" },
    unknownProperty3: { alert: "unknown", unusedItem1: "something" },
    unknownProperty4: { alert: "warning", unusedItem1: "something" },
    unknownProperty5: { alert: "warning", unusedItem1: "something" }
  }
];

const dataByProperty = data.reduce((a, obj) => {
  Object.entries(obj).forEach(([key, { alert }]) => {
    if (!a[key]) {
      a[key] = { unknown: 0, ok: 0, warning: 0, ko: 0 };
    }
    a[key][alert]++;
  });
  return a;
}, {});
console.log(dataByProperty);