From 4d52c74d318daf4eebb0dae43f581aa20ef62118 Mon Sep 17 00:00:00 2001
From: "moxey.eth" <jakemoxey@gmail.com>
Date: Sat, 16 Mar 2024 09:16:19 +1100
Subject: [PATCH] fix: #1960

---
 .changeset/small-shirts-admire.md         |  5 +++++
 src/utils/abi/encodeAbiParameters.test.ts | 20 ++++++++++++++++++++
 src/utils/abi/encodeAbiParameters.ts      |  5 +++++
 3 files changed, 30 insertions(+)
 create mode 100644 .changeset/small-shirts-admire.md

diff --git a/.changeset/small-shirts-admire.md b/.changeset/small-shirts-admire.md
new file mode 100644
index 0000000000..af6e678d01
--- /dev/null
+++ b/.changeset/small-shirts-admire.md
@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Fixed boolean conversion issue.
diff --git a/src/utils/abi/encodeAbiParameters.test.ts b/src/utils/abi/encodeAbiParameters.test.ts
index 539cb84623..cbb584a86a 100644
--- a/src/utils/abi/encodeAbiParameters.test.ts
+++ b/src/utils/abi/encodeAbiParameters.test.ts
@@ -1776,3 +1776,23 @@ test('getArrayComponents', () => {
   expect(getArrayComponents('uint256[][]')).toEqual([null, 'uint256[]'])
   expect(getArrayComponents('uint256')).toBeUndefined()
 })
+
+test('https://github.com/wevm/viem/issues/1960', () => {
+  expect(() =>
+    encodeAbiParameters(
+      [
+        {
+          name: 'boolz',
+          type: 'bool[]',
+          internalType: 'bool[]',
+        },
+      ] as const,
+      // @ts-expect-error
+      [['true']],
+    ),
+  ).toThrowErrorMatchingInlineSnapshot(`
+    [ViemError: Invalid boolean value: "true" (type: string). Expected: \`true\` or \`false\`.
+
+    Version: viem@1.0.2]
+  `)
+})
diff --git a/src/utils/abi/encodeAbiParameters.ts b/src/utils/abi/encodeAbiParameters.ts
index 6a76895f75..4670b8d5ad 100644
--- a/src/utils/abi/encodeAbiParameters.ts
+++ b/src/utils/abi/encodeAbiParameters.ts
@@ -20,6 +20,7 @@ import {
   InvalidAddressError,
   type InvalidAddressErrorType,
 } from '../../errors/address.js'
+import { BaseError } from '../../errors/base.js'
 import type { ErrorType } from '../../errors/utils.js'
 import type { Hex } from '../../types/misc.js'
 import { type IsAddressErrorType, isAddress } from '../address/isAddress.js'
@@ -311,6 +312,10 @@ export type EncodeBoolErrorType =
   | ErrorType
 
 function encodeBool(value: boolean): PreparedParam {
+  if (typeof value !== 'boolean')
+    throw new BaseError(
+      `Invalid boolean value: "${value}" (type: ${typeof value}). Expected: \`true\` or \`false\`.`,
+    )
   return { dynamic: false, encoded: padHex(boolToHex(value)) }
 }