1 files changed, 43 insertions, 0 deletions
diff --git a/app/scripts/controllers/network/createMetamaskMiddleware.js b/app/scripts/controllers/network/createMetamaskMiddleware.js
new file mode 100644
index 000000000..8b17829b7
--- /dev/null
+++ b/app/scripts/controllers/network/createMetamaskMiddleware.js
@@ -0,0 +1,43 @@
+const mergeMiddleware = require('json-rpc-engine/src/mergeMiddleware')
+const createScaffoldMiddleware = require('json-rpc-engine/src/createScaffoldMiddleware')
+const createAsyncMiddleware = require('json-rpc-engine/src/createAsyncMiddleware')
+const createWalletSubprovider = require('eth-json-rpc-middleware/wallet')
+
+module.exports = createMetamaskMiddleware
+
+function createMetamaskMiddleware ({
+  version,
+  getAccounts,
+  processTransaction,
+  processEthSignMessage,
+  processTypedMessage,
+  processPersonalMessage,
+  getPendingNonce,
+}) {
+  const metamaskMiddleware = mergeMiddleware([
+    createScaffoldMiddleware({
+      // staticSubprovider
+      eth_syncing: false,
+      web3_clientVersion: `MetaMask/v${version}`,
+    }),
+    createWalletSubprovider({
+      getAccounts,
+      processTransaction,
+      processEthSignMessage,
+      processTypedMessage,
+      processPersonalMessage,
+    }),
+    createPendingNonceMiddleware({ getPendingNonce }),
+  ])
+  return metamaskMiddleware
+}
+
+function createPendingNonceMiddleware ({ getPendingNonce }) {
+  return createAsyncMiddleware(async (req, res, next) => {
+    if (req.method !== 'eth_getTransactionCount') return next()
+    const address = req.params[0]
+    const blockRef = req.params[1]
+    if (blockRef !== 'pending') return next()
+    req.result = await getPendingNonce(address)
+  })
+}