From 8b5f2b8a4e875562ae8562de487c9c4cd75cd180 Mon Sep 17 00:00:00 2001
From: Simon Warta <simon@warta.it>
Date: Wed, 29 Jun 2022 08:52:00 +0200
Subject: [PATCH] Fix decoding of events with no attributes

---
 CHANGELOG.md                                  |  6 ++++
 .../tendermint34/adaptor/responses.spec.ts    | 30 +++++++++++++++++--
 .../src/tendermint34/adaptor/responses.ts     |  7 +++--
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e809dfdefa..e34e8dc38f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,12 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Fixed
+
+- @cosmjs/tendermint-rpc: Fix decoding events without attributes ([#1198]).
+
+[#1198]: https://github.com/cosmos/cosmjs/pull/1198
+
 ## [0.28.9] - 2022-06-21
 
 This version replaces the 0.28.8 release which was erroneously tagged as 0.26.8
diff --git a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
index d00a31209d..0ad26490ab 100644
--- a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
+++ b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
@@ -1,9 +1,35 @@
 /* eslint-disable @typescript-eslint/naming-convention */
-import { fromBase64, fromHex } from "@cosmjs/encoding";
+import { fromBase64, fromHex, toUtf8 } from "@cosmjs/encoding";
 
-import { decodeValidatorGenesis, decodeValidatorInfo, decodeValidatorUpdate } from "./responses";
+import { decodeEvent, decodeValidatorGenesis, decodeValidatorInfo, decodeValidatorUpdate } from "./responses";
 
 describe("Adaptor Responses", () => {
+  describe("decodeEvent", () => {
+    it("works with attributes", () => {
+      // from https://rpc.mainnet-1.tgrade.confio.run/tx?hash=0x2C44715748022DB2FB5F40105383719BFCFCEE51DBC02FF4088BE3F5924CD7BF
+      const event = decodeEvent({
+        type: "coin_spent",
+        attributes: [
+          { key: "c3BlbmRlcg==", value: "dGdyYWRlMWpzN2V6cm01NWZxZ3h1M3A2MmQ5eG42cGF0amt1Mno3bmU1ZHZn" },
+          { key: "YW1vdW50", value: "NjAwMDAwMDAwMHV0Z2Q=" },
+        ],
+      });
+      expect(event.type).toEqual("coin_spent");
+      expect(event.attributes).toEqual([
+        { key: toUtf8("spender"), value: toUtf8("tgrade1js7ezrm55fqgxu3p62d9xn6patjku2z7ne5dvg") },
+        { key: toUtf8("amount"), value: toUtf8("6000000000utgd") },
+      ]);
+    });
+
+    it("works with no attribute", () => {
+      const event = decodeEvent({
+        type: "cosmos.module.EmittedEvent",
+      });
+      expect(event.type).toEqual("cosmos.module.EmittedEvent");
+      expect(event.attributes).toEqual([]);
+    });
+  });
+
   describe("decodeValidatorGenesis", () => {
     it("works for genesis format", () => {
       // from https://raw.githubusercontent.com/cosmos/mainnet/master/genesis.json
diff --git a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
index f4ac865fa3..e7f1eefc33 100644
--- a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
@@ -111,13 +111,14 @@ function decodeAttributes(attributes: readonly RpcAttribute[]): responses.Attrib
 
 interface RpcEvent {
   readonly type: string;
-  readonly attributes: readonly RpcAttribute[];
+  /** Can be omitted (see https://github.com/cosmos/cosmjs/pull/1198) */
+  readonly attributes?: readonly RpcAttribute[];
 }
 
-function decodeEvent(event: RpcEvent): responses.Event {
+export function decodeEvent(event: RpcEvent): responses.Event {
   return {
     type: event.type,
-    attributes: decodeAttributes(event.attributes),
+    attributes: event.attributes ? decodeAttributes(event.attributes) : [],
   };
 }