Fix feature to work

app/scripts/controllers/transactions.js

@@ -180,7 +180,8 @@ module.exports = class TransactionController extends EventEmitter {
     // ensure value
     txMeta.gasPriceSpecified = Boolean(txParams.gasPrice)
     txMeta.nonceSpecified = Boolean(txParams.nonce)
-    const gasPrice = txParams.gasPrice || this.getGasPrice()
+    const gasPrice = txParams.gasPrice || this.getGasPrice ? this.getGasPrice()
+      : await this.query.gasPrice()
     txParams.gasPrice = ethUtil.addHexPrefix(gasPrice.toString(16))
     txParams.value = txParams.value || '0x0'
     // set gasLimit

app/scripts/metamask-controller.js

@@ -491,13 +491,20 @@ module.exports = class MetamaskController extends EventEmitter {
     const { recentBlocksController } = this
     const { recentBlocks } = recentBlocksController.store.getState()
     const lowestPrices = recentBlocks.map((block) => {
-      return block.transactions
+      if (!block.gasPrices) {
+        return new BN(0)
+      }
+      return block.gasPrices
+      .map(hexPrefix => hexPrefix.substr(2))
+      .map(hex => new BN(hex, 16))
       .sort((a, b) => {
         return a.gt(b) ? 1 : -1
       })[0]
     })
     .map(number => number.div(GWEI_BN).toNumber())
-    return percentile(50, lowestPrices)
+    const percentileNum = percentile(50, lowestPrices)
+    const percentileNumBn = new BN(percentileNum)
+    return '0x' + percentileNumBn.mul(GWEI_BN).toString(16)
   }
 
   //

test/unit/metamask-controller-test.js

@@ -55,8 +55,10 @@ describe('MetaMaskController', function () {
             getState: () => {
               return {
                 recentBlocks: [
-                  { transactions: [ new BN('50000000000'), new BN('100000000000') ] },
-                  { transactions: [ new BN('60000000000'), new BN('100000000000') ] },
+                  { gasPrices: [ '0x3b9aca00', '0x174876e800'] },
+                  { gasPrices: [ '0x3b9aca00', '0x174876e800'] },
+                  { gasPrices: [ '0x174876e800', '0x174876e800' ]},
+                  { gasPrices: [ '0x174876e800', '0x174876e800' ]},
                 ]
               }
             }
@@ -64,7 +66,7 @@ describe('MetaMaskController', function () {
         }
 
         const gasPrice = metamaskController.getGasPrice()
-        assert.equal(gasPrice, 50, 'accurately estimates 50th percentile accepted gas price')
+        assert.equal(gasPrice, '0x3b9aca00', 'accurately estimates 50th percentile accepted gas price')
 
         metamaskController.recentBlocksController = realRecentBlocksController
       })