Recursive Filter on Nested array

Question

I need to filter a nested structure, that looks like this, based on query. I need to return all objects, including the parent object of the subtree, which match the query string in object name. Please help, i am stuck.

[
   {
     name: 'bob',
     type: 1,
     children: [
       {
         name: 'bob',
         type: 2,
         children: [
           {
             name: 'mike',
             type: 3,
             children: [ 
               {
                 name:'bob',
                 type: 7,
                 children: []
               },
               {
                 name: 'mike',
                 type: 9,
                 children: []
               }
             ]
           }
         ]
       },
       {
         name: 'mike',
         type: 2
       }
     ]
   }
 ]

Right now i am able to find a match in the tree recursively, but the function returns the object on the first match and does not search deeper on sub levels in the same object. Any suggestions, how i can modify the code to go search through all levels recursively?

  return tree.map(copy).filter(function filterNested(node) {
    if (node.name.toLowerCase().indexOf(query) !== -1) {
      return true;
    }

    if (node.children) {
      return (node.children = node.children.map(copy).filter(filterNested))
        .length;
    }
  });

if I am searching for query 'bob', the expected result should be,

 const arr = [
   {
     name: 'bob',
     type: 1,
     children: [
       {
         name: 'bob',
         type: 2,
         children: [
           {
             name: 'mike',
             type: 3,
             children: [ 
               {
                 name:'bob',
                 type: 7
               },
  
             ]
           }
         ]
       },
     ]
   }
 ]

---

Answer 1

You could reduce the array and build new objects with optional children, if they have a length not zero.

function filter(array, fn) {
    return array.reduce((r, o) => {
        var children = filter(o.children || [], fn);
        if (fn(o) || children.length) r.push(Object.assign({}, o, children.length && { children }));
        return r;
    }, []);
}

var data = [{ name: 'bob', type: 1, children: [{ name: 'bob', type: 2, children: [{ name: 'mike', type: 3, children: [{ name: 'bob', type: 7 }, { name: 'same', typ: 9 }] }] }, { name: 'mike', type: 2 }] }],
    result = filter(data, ({ name }) => name.toLowerCase() === 'bob');

console.log(result);

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