dedupeByMatchingObjectsValues.js

export function dedupeByMatchingObjectsValues( keys , arrayOfObjects ) {
    return arrayOfObjects.filter( (item, i, inArray) => (
        inArray.find( target => (
            [].concat(keys).reduce( (bool, key) => bool && item[ key ]===target[ key ], true)
        ))===item
    ));
}

some-file.js

import {dedupeByMatchingObjectsValues} from './dedupeByMatchingObjectsValues.js';

let arrayWithDuplicates = [{a: 1, b:2}, {a: 2}, {a: 1, b:2}, {a: 1}, {a: 3}, {a: 1}, {a: 1}, {a: 2}, {a: 8}];

let unique = dedupeByMatchingObjectsValues(['a', 'b'], arrayWithDuplicates);

console.log(unique);
// [{"a":1,"b":2},{"a":2},{"a":1},{"a":3},{"a":8}]