fix: resolves #3705

Author: jxom

.changeset/twelve-shirts-kneel.md

@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Fixed issue where `decodeEventLog` would not check validity of the topic against the signature.

src/utils/abi/decodeEventLog.test.ts

@@ -1,8 +1,11 @@
 import { assertType, describe, expect, test } from 'vitest'
 
+import { waitForTransactionReceipt } from '../../actions/public/waitForTransactionReceipt.js'
+import { base } from '../../chains/index.js'
+import { createClient } from '../../clients/createClient.js'
+import { http } from '../../clients/transports/http.js'
 import { getAddress } from '../address/getAddress.js'
 import { toEventSelector } from '../hash/toEventSelector.js'
-
 import { decodeEventLog } from './decodeEventLog.js'
 
 test('Transfer()', () => {
@@ -193,7 +196,7 @@ test('unnamed args: mixed ordering of indexed args', () => {
     ],
     data: '0x0000000000000000000000000000000000000000000000000000000000000001',
     topics: [
-      '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef',
+      '0x138dbc8474f748db86063dcef24cef1495bc73385a946f8d691128085e5ebec2',
       '0x000000000000000000000000a5cc3c03994db5b0d9a5eedd10cabab0813678ac',
       '0x000000000000000000000000a5cc3c03994db5b0d9a5eedd10cabab0813678ac',
     ],
@@ -908,6 +911,69 @@ describe('GitHub repros', () => {
       )
     })
   })
+
+  test('https://github.com/wevm/viem/issues/3705', async () => {
+    const client = createClient({
+      chain: base,
+      transport: http(),
+    })
+
+    const receipt = await waitForTransactionReceipt(client, {
+      hash: '0xbee3f576c43a29d3c924cd46ff1ff42489eceae5e8e31afdbba8f982c8291a76',
+    })
+
+    const decoded = receipt.logs
+      .map((log) => {
+        try {
+          return decodeEventLog({
+            ...log,
+            abi: [
+              {
+                type: 'event',
+                name: 'PetRegistered',
+                inputs: [
+                  {
+                    name: 'petId',
+                    type: 'uint256',
+                    indexed: true,
+                    internalType: 'uint256',
+                  },
+                  {
+                    name: 'user',
+                    type: 'address',
+                    indexed: true,
+                    internalType: 'address',
+                  },
+                ],
+                anonymous: false,
+              },
+            ],
+          })
+        } catch {
+          return null
+        }
+      })
+      .filter((log) => log?.eventName === 'PetRegistered')
+
+    expect(decoded).toMatchInlineSnapshot(`
+      [
+        {
+          "args": {
+            "petId": 75574n,
+            "user": "0x03998b821AB247677a034762CA7F99fACF227975",
+          },
+          "eventName": "PetRegistered",
+        },
+        {
+          "args": {
+            "petId": 75575n,
+            "user": "0x03998b821AB247677a034762CA7F99fACF227975",
+          },
+          "eventName": "PetRegistered",
+        },
+      ]
+    `)
+  })
 })
 
 test("errors: event doesn't exist", () => {

src/utils/abi/decodeEventLog.ts

@@ -116,14 +116,11 @@ export function decodeEventLog<
   const [signature, ...argTopics] = topics
   if (!signature) throw new AbiEventSignatureEmptyTopicsError({ docsPath })
 
-  const abiItem = (() => {
-    if (abi.length === 1) return abi[0]
-    return abi.find(
-      (x) =>
-        x.type === 'event' &&
-        signature === toEventSelector(formatAbiItem(x) as EventDefinition),
-    )
-  })()
+  const abiItem = abi.find(
+    (x) =>
+      x.type === 'event' &&
+      signature === toEventSelector(formatAbiItem(x) as EventDefinition),
+  )
 
   if (!(abiItem && 'name' in abiItem) || abiItem.type !== 'event')
     throw new AbiEventSignatureNotFoundError(signature, { docsPath })