How to get unique array from nested object with lodash

Question

My collection contains the following (array of objects):

[
    {
        id: 'id-1',
        uniqueName: 'operation-level-1',
        operations: [
            {
                name: 'operaion-1',
                label: 'operation-1-label'
            },
            {
                name: 'operaion-2',
                label: 'operation-2-label'
            }
        ]
    },
    {
        id: 'id-2',
        uniqueName: 'operation-level-2'
        operations: [
            {
                name: 'operaion-1',
                label: 'operation-1-label'
            },
            {
                name: 'operaion-3',
                label: 'operation-3-label'
            }
        ]
    }

]

I wanted to get an array of unique operation name and label as shown below

const result = [
    {
        name: 'operaion-1',
        label: 'operation-1-label'
    },
    {
        name: 'operaion-2',
        label: 'operation-2-label'
    },
    {
        name: 'operaion-3',
        label: 'operation-3-label'
    }
]

Can someone suggest the best way to achieve this, please?

Answer 1

This can be easily done without lodash. You can first flat the data then map it as a key value pair and then make use of Map to remove the duplicate entries:

var data=[{ id: 'id-1', uniqueName: 'operation-level-1', operations: [ { name: 'operaion-1', label: 'operation-1-label' }, { name: 'operaion-2', label: 'operation-2-label' } ] }, { id: 'id-2', uniqueName: 'operation-level-2', operations: [ { name: 'operaion-1', label: 'operation-1-label' }, { name: 'operaion-3', label: 'operation-3-label' } ] }];

var result =  [...new Map(data.flatMap(({operations})=>operations).map(k=>([k.name, k]))).values()];

console.log(result);

Or if you do not want to use Map then use filter method:

var data=[{ id: 'id-1', uniqueName: 'operation-level-1', operations: [ { name: 'operaion-1', label: 'operation-1-label' }, { name: 'operaion-2', label: 'operation-2-label' } ] }, { id: 'id-2', uniqueName: 'operation-level-2', operations: [ { name: 'operaion-1', label: 'operation-1-label' }, { name: 'operaion-3', label: 'operation-3-label' } ] }];

var result = data.flatMap(({operations})=>operations).filter((val,i,self)=>self.findIndex(j=>j.name==val.name && j.label==val.label)==i);

console.log(result);