Trial Script to map any object/array to an structure object for easier interface mapping

script.js

console.log("structure", this.fetchObjectStructure([
  {
    attributes: [ 1, 2, 3 ]
  },
  {
    attributes: [ "a", "b" ]
  }
]));
fetchObjectStructure(data: any) {
    if(data === null) {
      return "null";
    }
    switch(data.__proto__.constructor.name) {
      case 'Object': {
        const structure: { [prop: string]: any, [prop: number]: any} = {};
        for(let key in data) {
          const temp = this.fetchObjectStructure(data[key]);
          if(structure[key] === undefined || structure[key] === "null") {
            structure[key] = temp;
            if(structure[key].__proto__.constructor.name==="String") {
              structure[key] = structure[key].toLowerCase() + ";";
            }
            return;
          }
          if(structure[key].__proto__.constructor.name === temp.__proto__.constructor.name) {
            if(structure[key].__proto__.constructor.name === "Object" && temp.__proto__.constructor.name === "Object") {
              Object.assign(structure[key], temp);
            } else if(structure[key].__proto__.constructor.name === 'Array' && temp.__proto__.constructor.name === 'Array') {
              Object.assign(structure[key][0], temp[0]);
            }
          } else {
            structure[key] = JSON.stringify(structure[key])+" | "+JSON.stringify(temp);
          }
        }
        return structure;
      }
      case 'Array': {
        let structure: any;
        for(let item of data) { 
          const subStructure = this.fetchObjectStructure(item);
          if(subStructure.__proto__.constructor.name === 'Object') {
            for(let key in subStructure) {
              if(structure[key] === undefined || structure[key] === "null") {
                structure[key] = subStructure[key];
                if(structure[key].__proto__.constructor.name==="String")
                  structure[key] = structure[key].toLowerCase() + ";";
              } else if(structure[key].__proto__.constructor.name === subStructure[key].__proto__.constructor.name) {
                if(structure[key].__proto__.constructor.name === "Object" && subStructure[key].__proto__.constructor.name === "Object") {
                  Object.assign(structure[key], subStructure[key]);
                } else if(structure[key].__proto__.constructor.name === 'Array' && subStructure[key].__proto__.constructor.name === 'Array') {
                  Object.assign(structure[key][0], subStructure[key][0]);
                }
              } else {
                structure[key] = JSON.stringify(structure[key])+" | "+JSON.stringify(subStructure[key]);
              }
            }
          } else if(subStructure.__proto__.constructor.name === 'Array') {

          } else {
            if(structure === null || structure === undefined || structure === 'null') {
              structure = subStructure;
            } else if(structure !== subStructure) {
              structure += structure+" | "+subStructure;
            }
          }
        }
        return [structure];
      }
      default:
        return data.__proto__.constructor.name;
    }
  }

Script fails and returns a "circular" object with the current temp input.