2 files changed, 163 insertions, 0 deletions
diff --git a/app/scripts/controllers/transactions/lib/tx-state-history-helper.js b/app/scripts/controllers/transactions/lib/tx-state-history-helper.js
new file mode 100644
index 000000000..59a4b562c
--- /dev/null
+++ b/app/scripts/controllers/transactions/lib/tx-state-history-helper.js
@@ -0,0 +1,64 @@
+const jsonDiffer = require('fast-json-patch')
+const clone = require('clone')
+/** @module*/
+module.exports = {
+  generateHistoryEntry,
+  replayHistory,
+  snapshotFromTxMeta,
+  migrateFromSnapshotsToDiffs,
+}
+
+/**
+  converts non-initial history entries into diffs
+  @param longHistory {array}
+  @returns {array}
+*/
+function migrateFromSnapshotsToDiffs (longHistory) {
+  return (
+    longHistory
+    // convert non-initial history entries into diffs
+    .map((entry, index) => {
+      if (index === 0) return entry
+      return generateHistoryEntry(longHistory[index - 1], entry)
+    })
+  )
+}
+
+/**
+  generates an array of history objects sense the previous state.
+  The object has the keys opp(the operation preformed),
+  path(the key and if a nested object then each key will be seperated with a `/`)
+  value
+  with the first entry having the note
+  @param previousState {object} - the previous state of the object
+  @param newState {object} - the update object
+  @param note {string} - a optional note for the state change
+  @reurns {array}
+*/
+function generateHistoryEntry (previousState, newState, note) {
+  const entry = jsonDiffer.compare(previousState, newState)
+  // Add a note to the first op, since it breaks if we append it to the entry
+  if (note && entry[0]) entry[0].note = note
+  return entry
+}
+
+/**
+  Recovers previous txMeta state obj
+  @return {object}
+*/
+function replayHistory (_shortHistory) {
+  const shortHistory = clone(_shortHistory)
+  return shortHistory.reduce((val, entry) => jsonDiffer.applyPatch(val, entry).newDocument)
+}
+
+/**
+  @param txMeta {Object}
+  @returns {object} a clone object of the txMeta with out history
+*/
+function snapshotFromTxMeta (txMeta) {
+  // create txMeta snapshot for history
+  const snapshot = clone(txMeta)
+  // dont include previous history in this snapshot
+  delete snapshot.history
+  return snapshot
+}
diff --git a/app/scripts/controllers/transactions/lib/util.js b/app/scripts/controllers/transactions/lib/util.js
new file mode 100644
index 000000000..84f7592a0
--- /dev/null
+++ b/app/scripts/controllers/transactions/lib/util.js
@@ -0,0 +1,99 @@
+const {
+  addHexPrefix,
+  isValidAddress,
+} = require('ethereumjs-util')
+
+/**
+@module
+*/
+module.exports = {
+  normalizeTxParams,
+  validateTxParams,
+  validateFrom,
+  validateRecipient,
+  getFinalStates,
+}
+
+
+// functions that handle normalizing of that key in txParams
+const normalizers = {
+  from: from => addHexPrefix(from).toLowerCase(),
+  to: to => addHexPrefix(to).toLowerCase(),
+  nonce: nonce => addHexPrefix(nonce),
+  value: value => addHexPrefix(value),
+  data: data => addHexPrefix(data),
+  gas: gas => addHexPrefix(gas),
+  gasPrice: gasPrice => addHexPrefix(gasPrice),
+}
+
+ /**
+  normalizes txParams
+  @param txParams {object}
+  @returns {object} normalized txParams
+ */
+function normalizeTxParams (txParams) {
+  // apply only keys in the normalizers
+  const normalizedTxParams = {}
+  for (const key in normalizers) {
+    if (txParams[key]) normalizedTxParams[key] = normalizers[key](txParams[key])
+  }
+  return normalizedTxParams
+}
+
+ /**
+  validates txParams
+  @param txParams {object}
+ */
+function validateTxParams (txParams) {
+  validateFrom(txParams)
+  validateRecipient(txParams)
+  if ('value' in txParams) {
+    const value = txParams.value.toString()
+    if (value.includes('-')) {
+      throw new Error(`Invalid transaction value of ${txParams.value} not a positive number.`)
+    }
+
+    if (value.includes('.')) {
+      throw new Error(`Invalid transaction value of ${txParams.value} number must be in wei`)
+    }
+  }
+}
+
+ /**
+  validates the from field in  txParams
+  @param txParams {object}
+ */
+function validateFrom (txParams) {
+  if (!(typeof txParams.from === 'string')) throw new Error(`Invalid from address ${txParams.from} not a string`)
+  if (!isValidAddress(txParams.from)) throw new Error('Invalid from address')
+}
+
+ /**
+  validates the to field in  txParams
+  @param txParams {object}
+ */
+function validateRecipient (txParams) {
+  if (txParams.to === '0x' || txParams.to === null) {
+    if (txParams.data) {
+      delete txParams.to
+    } else {
+      throw new Error('Invalid recipient address')
+    }
+  } else if (txParams.to !== undefined && !isValidAddress(txParams.to)) {
+    throw new Error('Invalid recipient address')
+  }
+  return txParams
+}
+
+  /**
+    @returns an {array} of states that can be considered final
+  */
+function getFinalStates () {
+  return [
+    'rejected', // the user has responded no!
+    'confirmed', // the tx has been included in a block.
+    'failed', // the tx failed for some reason, included on tx data.
+    'dropped', // the tx nonce was already used
+  ]
+}
+