metamask-extension/test/unit/migrations/027-test.js

const assert = require('assert')
const migration27 = require('../../../app/scripts/migrations/027')

const oldStorage = {
  'meta': {},
  'data': {
    'TransactionController': {
      'transactions': [
      ],
    },
  },
}

const transactions = []


while (transactions.length < 9) {
  transactions.push({status: 'rejected'})
  transactions.push({status: 'unapproved'})
  transactions.push({status: 'approved'})
}


oldStorage.data.TransactionController.transactions = transactions

describe('migration #27', () => {
  it('should remove rejected transactions', (done) => {
    migration27.migrate(oldStorage)
      .then((newStorage) => {
        const newTransactions = newStorage.data.TransactionController.transactions
        assert.equal(newTransactions.length, 6, 'transactions is expected to have the length of 6')
        newTransactions.forEach((txMeta) => {
          if (txMeta.status === 'rejected') done(new Error('transaction was found with a status of rejected'))
        })
        done()
      })
      .catch(done)
  })

  it('should successfully migrate first time state', (done) => {
    migration27.migrate({
      meta: {},
      data: require('../../../app/scripts/first-time-state'),
    })
      .then((migratedData) => {
        assert.equal(migratedData.meta.version, migration27.version)
        done()
      }).catch(done)
  })
})