metamask-extension/app/scripts/controllers/permissions/selectors.test.js

import { cloneDeep } from 'lodash';
import { getChangedAccounts, getPermittedAccountsByOrigin } from './selectors';

describe('PermissionController selectors', () => {
  describe('getChangedAccounts', () => {
    it('returns the new value if the previous value is undefined', () => {
      const newAccounts = new Map([['foo.bar', ['0x1']]]);
      expect(getChangedAccounts(newAccounts)).toBe(newAccounts);
    });

    it('returns an empty map if the new and previous values are the same', () => {
      const newAccounts = new Map([['foo.bar', ['0x1']]]);
      expect(getChangedAccounts(newAccounts, newAccounts)).toStrictEqual(
        new Map(),
      );
    });

    it('returns a new map of the changed accounts if the new and previous values differ', () => {
      // We set this on the new and previous value under the key 'foo.bar' to
      // check that identical values are excluded.
      const identicalValue = ['0x1'];

      const previousAccounts = new Map([
        ['bar.baz', ['0x1']], // included: different accounts
        ['fizz.buzz', ['0x1']], // included: removed in new value
      ]);
      previousAccounts.set('foo.bar', identicalValue);

      const newAccounts = new Map([
        ['bar.baz', ['0x1', '0x2']], // included: different accounts
        ['baz.fizz', ['0x3']], // included: brand new
      ]);
      newAccounts.set('foo.bar', identicalValue);

      expect(getChangedAccounts(newAccounts, previousAccounts)).toStrictEqual(
        new Map([
          ['bar.baz', ['0x1', '0x2']],
          ['fizz.buzz', []],
          ['baz.fizz', ['0x3']],
        ]),
      );
    });
  });

  describe('getPermittedAccountsByOrigin', () => {
    it('memoizes and gets permitted accounts by origin', () => {
      const state1 = {
        subjects: {
          'foo.bar': {
            origin: 'foo.bar',
            permissions: {
              eth_accounts: {
                caveats: [{ type: 'restrictReturnedAccounts', value: ['0x1'] }],
              },
            },
          },
          'bar.baz': {
            origin: 'bar.baz',
            permissions: {
              eth_accounts: {
                caveats: [{ type: 'restrictReturnedAccounts', value: ['0x2'] }],
              },
            },
          },
          'baz.bizz': {
            origin: 'baz.fizz',
            permissions: {
              eth_accounts: {
                caveats: [
                  { type: 'restrictReturnedAccounts', value: ['0x1', '0x2'] },
                ],
              },
            },
          },
          'no.accounts': {
            // we shouldn't see this in the result
            permissions: {
              foobar: {},
            },
          },
        },
      };

      const expected1 = new Map([
        ['foo.bar', ['0x1']],
        ['bar.baz', ['0x2']],
        ['baz.fizz', ['0x1', '0x2']],
      ]);

      const selected1 = getPermittedAccountsByOrigin(state1);

      expect(selected1).toStrictEqual(expected1);
      // The selector should return the memoized value if state.subjects is
      // the same object
      expect(selected1).toBe(getPermittedAccountsByOrigin(state1));

      // If we mutate the state, the selector return value should be different
      // from the first.
      const state2 = cloneDeep(state1);
      delete state2.subjects['foo.bar'];

      const expected2 = new Map([
        ['bar.baz', ['0x2']],
        ['baz.fizz', ['0x1', '0x2']],
      ]);

      const selected2 = getPermittedAccountsByOrigin(state2);

      expect(selected2).toStrictEqual(expected2);
      expect(selected2).not.toBe(selected1);
      // Since we didn't mutate the state at this point, the value should once
      // again be the memoized.
      expect(selected2).toBe(getPermittedAccountsByOrigin(state2));
    });
  });
});