Remove duplicate objects with condition

Suppose I have a list of objects like this:

let b = [
  {
    name: "test1", 
    connectedTo: "",
  },
  {
    name: "test1",
    connectedTo: "test1.test2.test3"
  },
  {
    name: "test2",
    connectedTo: "",
  },
  {
    name: "test3",
    connectedTo: "",
  }
]

I want to get elements without duplicates name and also if there are duplicates take one without empty connectedTo. So from example above the result that I expect is:

let result = [
  {
    name: "test1",
    connectedTo: "test1.test2.test3"
  },
  {
    name: "test2",
    connectedTo: "",
  },
  {
    name: "test3",
    connectedTo: "",
  }
]

Answer

Here’s an approach utilizing Array#reduce function:

let b = [
  {
    name: "test1", 
    connectedTo: "",
  },
  {
    name: "test1",
    connectedTo: "test1.test2.test3"
  },
  {
    name: "test2",
    connectedTo: "",
  },
  {
    name: "test3",
    connectedTo: "test1.test2",
  },
  {
    name: "test3",
    connectedTo: "",
  }
];

const result = Object.values(b.reduce((acc, cur) => {
  if(!acc[cur.name] || !acc[cur.name].connectedTo)
    acc[cur.name] = cur;
  return acc;
}, {}));

console.log(result);