Typings and comment

2 files changed, 6 insertions, 1 deletions

diff --git a/packages/utils/package.json b/packages/utils/package.json
index ee5953801..f4f39956c 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -36,7 +36,7 @@
     },
     "dependencies": {
         "ethereum-types": "^0.0.1",
-        "@0xproject/typescript-typings": "^0.4.1",
+        "@0xproject/typescript-typings": "^0.4.2",
         "@types/node": "^8.0.53",
         "ethereumjs-util": "^5.1.1",
         "bignumber.js": "~4.1.0",
diff --git a/packages/utils/src/abi_decoder.ts b/packages/utils/src/abi_decoder.ts
index 1f805c2f1..390423644 100644
--- a/packages/utils/src/abi_decoder.ts
+++ b/packages/utils/src/abi_decoder.ts
@@ -37,6 +37,11 @@ export class AbiDecoder {
           decodedData = ethersInterface.events[event.name].parse(log.data);
         } catch (error) {
           if (error.code === ethers.errors.INVALID_ARGUMENT) {
+            // Because we index events by Method ID, and Method IDs are derived from the method
+            // name and the input parameters, it's possible that the return value of the event
+            // does not match our ABI. If that's the case, then ethers will throw an error
+            // when we try to parse the event. We handle that case here by returning the log rather
+            // than throwing an error.
             return log;
           }
           throw error;