migration for removing unnecessary transactions from state

app/scripts/migrations/023.js

@@ -0,0 +1,50 @@
+
+const version = 23
+
+/*
+
+This migration removes transactions that are no longer usefull down to 40 total
+
+*/
+
+const clone = require('clone')
+
+module.exports = {
+  version,
+
+  migrate: function (originalVersionedData) {
+    const versionedData = clone(originalVersionedData)
+    versionedData.meta.version = version
+    try {
+      const state = versionedData.data
+      const newState = transformState(state)
+      versionedData.data = newState
+    } catch (err) {
+      console.warn(`MetaMask Migration #${version}` + err.stack)
+    }
+    return Promise.resolve(versionedData)
+  },
+}
+
+function transformState (state) {
+  const newState = state
+  const transactions = newState.TransactionController.transactions
+
+  if (transactions.length <= 40) return newState
+
+  let reverseTxList = transactions.reverse()
+  let stripping = true
+  while (reverseTxList.length > 40 && stripping) {
+    let txIndex = reverseTxList.findIndex((txMeta) => {
+      return (txMeta.status === 'failed' ||
+      txMeta.status === 'rejected' ||
+      txMeta.status === 'confirmed' ||
+      txMeta.status === 'dropped')
+    })
+    if (txIndex < 0) stripping = false
+    else reverseTxList.splice(txIndex, 1)
+  }
+
+  newState.TransactionController.transactions = reverseTxList.reverse()
+  return newState
+}

app/scripts/migrations/index.js

@@ -32,4 +32,6 @@ module.exports = [
   require('./019'),
   require('./020'),
   require('./021'),
+  require('./022'),
+  require('./023'),
 ]

test/unit/migrations/023-test.js

@@ -0,0 +1,99 @@
+const assert = require('assert')
+const migration23 = require('../../../app/scripts/migrations/023')
+const properTime = (new Date()).getTime()
+const storage = {
+  "meta": {},
+  "data": {
+    "TransactionController": {
+      "transactions": [
+      ]
+    },
+  },
+}
+
+const transactions = []
+const transactions40 = []
+const transactions20 = []
+
+const txStates = [
+  'unapproved',
+  'approved',
+  'signed',
+  'submitted',
+  'confirmed',
+  'rejected',
+  'failed',
+  'dropped',
+]
+
+const deletableTxStates = [
+  'confirmed',
+  'rejected',
+  'failed',
+  'dropped',
+]
+
+let nonDeletableCount = 0
+
+let status
+while (transactions.length <= 100) {
+  status = txStates[Math.floor(Math.random() * Math.floor(txStates.length - 1))]
+  if (!deletableTxStates.find((s) => s === status)) nonDeletableCount++
+  transactions.push({status})
+}
+
+while (transactions40.length < 40) {
+  status = txStates[Math.floor(Math.random() * Math.floor(txStates.length - 1))]
+  transactions40.push({status})
+}
+
+while (transactions20.length < 20) {
+  status = txStates[Math.floor(Math.random() * Math.floor(txStates.length - 1))]
+  transactions20.push({status})
+}
+
+
+
+storage.data.TransactionController.transactions = transactions
+
+describe('storage is migrated successfully and the proper transactions are remove from state', () => {
+  it('should remove transactions that are unneeded', (done) => {
+    migration23.migrate(storage)
+    .then((migratedData) => {
+      let leftoverNonDeletableTxCount = 0
+      const migratedTransactions = migratedData.data.TransactionController.transactions
+      migratedTransactions.forEach((tx) => {
+        if (!deletableTxStates.find((s) => s === tx.status)) {
+          leftoverNonDeletableTxCount++
+        }
+      })
+      assert.equal(leftoverNonDeletableTxCount, nonDeletableCount, 'migration shouldnt delete transactions we want to keep')
+      assert((migratedTransactions.length >= 40), `should be equal or greater to 40 if they are non deletable states got ${migratedTransactions.length} transactions`)
+      done()
+    }).catch(done)
+  })
+
+  it('should not remove any transactions because 40 is the expectable limit', (done) => {
+    storage.meta.version = 22
+    storage.data.TransactionController.transactions = transactions40
+    migration23.migrate(storage)
+    .then((migratedData) => {
+      const migratedTransactions = migratedData.data.TransactionController.transactions
+
+      assert.equal(migratedTransactions.length, 40, 'migration shouldnt delete when at limit')
+      done()
+    }).catch(done)
+  })
+
+  it('should not remove any transactions because 20 txs is under the expectable limit', (done) => {
+    storage.meta.version = 22
+    storage.data.TransactionController.transactions = transactions20
+    migration23.migrate(storage)
+    .then((migratedData) => {
+      const migratedTransactions = migratedData.data.TransactionController.transactions
+      assert.equal(migratedTransactions.length, 20, 'migration shouldnt delete when under limit')
+      done()
+    }).catch(done)
+  })
+
+})