should throw on invalid stateRoots

Author: wanderer

index.js

@@ -149,7 +149,10 @@ module.exports = class Hypervisor {
   async setStateRoot (stateRoot) {
     this.tree.root = stateRoot
     const node = await this.tree.get(Buffer.from([0]))
-    this.nonce = node.value || 0
+    if (!node.value) {
+      throw new Error('invalid state root')
+    }
+    this.nonce = node.value
   }
 
   /**

tests/index.js

@@ -266,7 +266,7 @@ tape('three communicating actors, with tick counting', async t => {
 })
 
 tape('errors', async t => {
-  t.plan(3)
+  t.plan(4)
   const expectedState = Buffer.from('25bc7e81511bfded44a1846f4bca1acc99f24273', 'hex')
   const tree = new RadixTree({
     db
@@ -306,6 +306,12 @@ tape('errors', async t => {
   hypervisor.send(message)
   const stateRoot = await hypervisor.createStateRoot()
   t.deepEquals(stateRoot, expectedState, 'expected root!')
+
+  try {
+    await hypervisor.setStateRoot(Buffer.from([0]))
+  } catch (e) {
+    t.pass('should catch invalid state roots')
+  }
 })
 
 tape('out-of-gas', async t => {