When checking pending txs, check for successful txs with same nonce.

If a successful tx with the same nonce exists, transition tx to the failed state.

Fixes #2294

app/scripts/lib/pending-tx-tracker.js

@@ -25,6 +25,7 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
     // default is one day
     this.retryTimePeriod = config.retryTimePeriod || 86400000
     this.getPendingTransactions = config.getPendingTransactions
+    this.getCompletedTransactions = config.getCompletedTransactions
     this.publishTransaction = config.publishTransaction
   }
 
@@ -120,6 +121,7 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
   async _checkPendingTx (txMeta) {
     const txHash = txMeta.hash
     const txId = txMeta.id
+
     // extra check in case there was an uncaught error during the
     // signature and submission process
     if (!txHash) {
@@ -128,6 +130,15 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
       this.emit('tx:failed', txId, noTxHashErr)
       return
     }
+
+    // If another tx with the same nonce is mined, set as failed.
+    const taken = await this._checkIfNonceIsTaken(txMeta)
+    if (taken) {
+      const nonceTakenErr = new Error('Another transaction with this nonce has been mined.')
+      nonceTakenErr.name = 'NonceTakenErr'
+      return this.emit('tx:failed', txId, nonceTakenErr)
+    }
+
     // get latest transaction status
     let txParams
     try {
@@ -159,4 +170,13 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
     }
     nonceGlobalLock.releaseLock()
   }
+
+  async _checkIfNonceIsTaken (txMeta) {
+    const completed = this.getCompletedTransactions()
+    const sameNonce = completed.filter((otherMeta) => {
+      return otherMeta.txParams.nonce === txMeta.txParams.nonce
+    })
+    return sameNonce.length > 0
+  }
+
 }