Compares two objects to determine if the first one contains equivalent property values to the second one.

  • Use Object.keys() to get all the keys of the second object.
  • Use Array.prototype.every(), Object.prototype.hasOwnProperty() and strict comparison to determine if all keys exist in the first object and have the same values.
const matches = (obj, source) =>
    key => obj.hasOwnProperty(key) && obj[key] === source[key]
matches({ age: 25, hair: 'long', beard: true }, { hair: 'long', beard: true });
// true
matches({ hair: 'long', beard: true }, { age: 25, hair: 'long', beard: true });
// false