groupBy based on range of values using RxJS in angular

Question

I have a raw data array

[
  {bugid: b1 , state: 'foo', days: 2}, 
  {bugid: b2, state: 'bar', days: 41}, 
  {bugid: b3, state: 'foo', days: 45}
]

I want to group this data using RxJS in this format

{
  '0-25': [{ name: foo, value: 1}, {name: bar, value: 0}], 
  '26-50': [{name: foo, value: 1}, {name: bar, value: 1}]
}

I am not able to group in the range

Answer 1

You don't need rxjs for this.

const data = [
  { state: 'foo', days: 2 }, 
  { state: 'bar', days: 41 }, 
  { state: 'foo', days: 45 }
];

// get all possible states
const states = [...new Set(data.map(item => item.state))];

const result = {
  '0-25': getCounts(0, 25),
  '26-60': getCounts(26, 50)
};

function getCounts(from, to) {
  return states.map(state => ({ name: state, value: getValue(state, from, to) }));
}

function getValue(state, from, to) {
  return data.filter(item => item.state === state && item.days >= from && item.days <= to).length;
}