Fix error message on parse failure

Author: mkruskal-google

src/root.js

@@ -110,16 +110,16 @@ Root.prototype.load = function load(filename, options, callback) {
 
     // Finishes loading by calling the callback (exactly once)
     function finish(err, root) {
-        if (root) {
-            root.resolveAll();
-        }
         /* istanbul ignore if */
         if (!callback) {
             return;
         }
         if (sync) {
             throw err;
         }
+        if (root) {
+            root.resolveAll();
+        }
         var cb = callback;
         callback = null;
         cb(err, root);

tests/comp_parse-uncommon.js

@@ -34,3 +34,13 @@ function traverseTypes(current, fn) {
             traverseTypes(nested, fn);
         });
 }
+
+tape.test("invalid lookup", async function(test) {
+    try {
+        await protobuf.load("tests/data/invalid-lookup.proto");
+        test.fail("should have thrown");
+    } catch(err) {
+        test.match(err.message, /illegal token 'required'/, "failed to parse");
+    }
+});
+

tests/data/invalid-lookup.proto

@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package test;
+
+service MyService {
+  rpc MyMethod (InvalidMessage) returns (stream InvalidMessage) {};
+}
+
+message InvalidMessage {
+  required bad_field = 1;
+}