UUIDV4 in for loop not changing value

Question

I am trying to create a function to generate an array of objects with a UUID as the key, as well as a UUID for some of the nested object ids.

Each game will be based on a mock object which I import into the file.

The function expects a sport (string) which will get assigned to a key and a quantity (number) which will determine the for loop iterations.

When using a for loop the UUID for the nested object ids are getting overridden on each iteration.

const mockGame = require('../mock-game');
const uuidv4 = require('uuid/v4');

function generateMockGames(sport, quantity) {
    let games = []

    for (let i = 0; i < quantity; i++) {
        let game = {}
        let id = uuidv4()

        game[id] = {
            search: mockGame.search,
            query: mockGame.query,
            variables: mockGame.variables,
        }

        game[id].search.eventId = id
        game[id].search.competition.categoryName = sport

        game[id].search.id = id
        game[id].search.competition.categoryName = sport;

        games.push(game);
    }

    return games;
}

const mockFootballGame = generateMockGames('football', 3);

Expected result:

[
  {
    '286c1911-b155-4197-bbde-64dba0b304fe': {
       search: {
           eventId: '286c1911-b155-4197-bbde-64dba0b304fe',
           name: 'test name',
           competition: {
               categoryName: 'football'
           }
      },
      query: {
           id: '286c1911-b155-4197-bbde-64dba0b304fe',
           competition: {
               categoryName: 'football'
           }
      },
      variables: {
           name: 'test name'
      }
  },
  {
    '082a46a6-4dde-433d-8011-9e94a5ee79ff': {
       search: {
           eventId: '082a46a6-4dde-433d-8011-9e94a5ee79ff',
           name: 'test name',
           competition: {
               categoryName: 'football'
           }
      },
      query: {
           id: '082a46a6-4dde-433d-8011-9e94a5ee79ff',
           competition: {
               categoryName: 'football'
           }
      },
      variables: {
           name: 'test name'
      }
  },
  {
    'ba911751-3ea3-40ab-9bec-c525ab2a07b9': {
       search: {
           eventId: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           name: 'test name',
           competition: {
               categoryName: 'football'
           }
      },
      query: {
           id: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           competition: {
               categoryName: 'football'
           }
      },
      variables: {
           name: 'test name'
      }
  }
]

Output is:

[
  {
    '286c1911-b155-4197-bbde-64dba0b304fe': {
       search: {
           eventId: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           name: 'test name',
           competition: {
               categoryName: 'football'
           }
      },
      query: {
           id: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           competition: {
               categoryName: 'football'
           }
      },
      variables: {
           name: 'test name'
      }
  },
  {
    '082a46a6-4dde-433d-8011-9e94a5ee79ff': {
       search: {
           eventId: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           name: 'test name',
           competition: {
               categoryName: 'football'
           }
      },
      query: {
           id: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           competition: {
               categoryName: 'football'
           }
      },
      variables: {
           name: 'test name'
      }
  },
  {
    'ba911751-3ea3-40ab-9bec-c525ab2a07b9': {
       search: {
           eventId: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           name: 'test name',
           competition: {
               categoryName: 'football'
           }
      },
      query: {
           id: 'ba911751-3ea3-40ab-9bec-c525ab2a07b9',
           competition: {
               categoryName: 'football'
           }
      },
      variables: {
           name: 'test name'
      }
  }
]

Answer 1

You are assigning subobjects of mockGame in your loop to the entries, without copying them. So you keep overwriting mockGame.query.id etc, with a new uuid in your loop, but then assign the mockGame.query object as a whole to your output.