fix(@embark/ens): make resolve() work with promises and callbacks

Changes in c64c093a48 resulted in a regression
that ENS functions within console/dashboard didn't work properly anymore.

This commit ensures that both APIs, `EmbarkJS.Names.resolve()` as well as
`EmbarkJS.Names.lookup()` can be either used using `async/await` or promised
based syntax within the console/dashboard.

Example:

```
await EmbarkJS.Names.resolve('me.eth.eth');

EmbarkJS.Names.resolve('me.eth.eth').then(val => ..., err => ...)

EmbarkJS.Names.resolve('me.eth.eth', (err, val) => ...)
```

Same with:

```
await EmbarkJS.Names.lookup('0x...');

EmbarkJS.Names.lookup('0x...').then(val => ..., err => ...)

EmbarkJS.Names.lookup('0x...', (err, val) => ...)
```

src/lib/core/modules/coderunner/codeRunner.js

@@ -96,7 +96,7 @@ class CodeRunner {
       cb(null, value);
     } catch (error) {
       // Improve error message when there's no connection to node
-      if (error.message.indexOf(WEB3_INVALID_RESPONSE_ERROR) !== -1) {
+      if (error.message && error.message.indexOf(WEB3_INVALID_RESPONSE_ERROR) !== -1) {
         error.message += '. Are you connected to an Ethereum node?';
       }
 

src/lib/modules/ens/embarkjs.js

@@ -172,71 +172,81 @@ __embarkENS.setProvider = function (config) {
 };
 
 __embarkENS.resolve = function (name, callback) {
-  callback = callback || function () {};
+  return new Promise((resolve, reject) => {
+
+    function resolveOrReject(err, addr) {
+      if (err) {
+        if (err === NoDecodeAddrError) {
+          err = `${name} is not registered`;
+          addr = '0x';
+        }
+        return !callback ? reject(err) : callback(err);
+      }
+      return !callback ? resolve(addr) : callback(err, addr);
+    }
+
     if (!this.ens) {
-    return callback(providerNotSetError);
+      resolveOrReject(providerNotSetError);
     }
     if (!web3.eth.defaultAccount) {
-    return callback(defaultAccountNotSetError);
+      resolveOrReject(defaultAccountNotSetError);
     }
 
     let node = namehash.hash(name);
 
-  function cb(err, addr) {
-    if (err === NoDecodeAddrError) {
-      return callback(name + " is not registered", "0x");
-    }
-    callback(err, addr);
-  }
-
-  return this.ens.methods.resolver(node).call()
-    .then(resolverAddress => {
-      if (resolverAddress === voidAddress) {
-        return cb('Name not yet registered');
+    this.ens.methods.resolver(node).call().then(resolvedAddress => {
+      if (resolvedAddress === voidAddress) {
+        return resolveOrReject('Name not yet registered');
       }
       let resolverContract = new EmbarkJS.Blockchain.Contract({
         abi: this.resolverInterface,
-        address: resolverAddress,
+        address: resolvedAddress,
         web3: web3
       });
-      return resolverContract.methods.addr(node).call(cb);
-    })
-    .catch(cb);
+      resolverContract.methods.addr(node).call(resolveOrReject);
+    }).catch(resolveOrReject);
+  });
 };
 
 __embarkENS.lookup = function (address, callback) {
-  callback = callback || function () {};
+  return new Promise((resolve, reject) => {
+
+    function resolveOrReject(err, name) {
+      if (err) {
+        if (err === NoDecodeStringError || err === NoDecodeAddrError) {
+          err = 'Address does not resolve to name. Try syncing chain.';
+        }
+        return !callback ? reject(err) : callback(err);
+      }
+      return !callback ? resolve(name) : callback(err, name);
+    }
+
     if (!this.ens) {
-    return callback(providerNotSetError);
+      return resolveOrReject(providerNotSetError);
     }
+
     if (!web3.eth.defaultAccount) {
-    return callback(defaultAccountNotSetError);
+      return resolveOrReject(defaultAccountNotSetError);
     }
+
     if (address.startsWith("0x")) {
       address = address.slice(2);
     }
+
     let node = web3.utils.soliditySha3(address.toLowerCase() + reverseAddrSuffix);
 
-  function cb(err, name) {
-    if (err === NoDecodeStringError || err === NoDecodeAddrError) {
-      return callback('Address does not resolve to name. Try syncing chain.');
-    }
-    return callback(err, name);
-  }
-
-  return this.ens.methods.resolver(node).call()
-    .then(resolverAddress => {
+    this.ens.methods.resolver(node).call().then(resolverAddress => {
       if (resolverAddress === voidAddress) {
-        return cb('Address not associated to a resolver');
+        return resolveOrReject('Address not associated to a resolver');
       }
       const resolverContract = new EmbarkJS.Blockchain.Contract({
         abi: this.resolverInterface,
         address: resolverAddress,
         web3: web3
       });
-      return resolverContract.methods.name(node).call(cb);
-    })
-    .catch(cb);
+      resolverContract.methods.name(node).call(resolveOrReject);
+    }).catch(resolveOrReject);
+  });
 };
 
 __embarkENS.registerSubDomain = function (name, address, callback) {