From 7a6e49200949325f69a05b3bf465ce64eb41bb8d Mon Sep 17 00:00:00 2001
From: Muhammad Altabba <24407834+Muhammad-Altabba@users.noreply.github.com>
Date: Thu, 5 Sep 2024 16:09:32 +0200
Subject: [PATCH] Handle common cases for smart contract errors according to
 EIP 838 (#7155)

* handle smart contracts errors `Error(string)` and `Panic(uint256)`

* add tests

* update CHANGELOG.md
---
 packages/web3-eth-abi/CHANGELOG.md            |  5 ++-
 .../src/decode_contract_error_data.ts         | 30 ++++++++++++++++
 packages/web3-eth-abi/test/fixtures/data.ts   | 34 +++++++++++++++++++
 .../test/unit/decodeContractErrorData.test.ts |  8 ++++-
 4 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/packages/web3-eth-abi/CHANGELOG.md b/packages/web3-eth-abi/CHANGELOG.md
index 6d04047ddef..1bb5910ba18 100644
--- a/packages/web3-eth-abi/CHANGELOG.md
+++ b/packages/web3-eth-abi/CHANGELOG.md
@@ -182,4 +182,7 @@ Documentation:
 
 -   fix encodedata in EIP-712 (#7095)
 
-## [Unreleased]
\ No newline at end of file
+## [Unreleased]
+
+### Added
+-   Handle common cases for smart contract errors according to EIP 838: `0x4e487b71` which is the ‘selector’ for `Panic(uint256)` and `0x08c379a0` is the ‘selector’ of `Error(string)`. (7155)
diff --git a/packages/web3-eth-abi/src/decode_contract_error_data.ts b/packages/web3-eth-abi/src/decode_contract_error_data.ts
index 98eb02d4fd8..11566b79645 100644
--- a/packages/web3-eth-abi/src/decode_contract_error_data.ts
+++ b/packages/web3-eth-abi/src/decode_contract_error_data.ts
@@ -39,6 +39,36 @@ export const decodeContractErrorData = (
 				errorSignature = jsonInterfaceMethodToString(errorAbi);
 				// decode abi.inputs according to EIP-838
 				errorArgs = decodeParameters([...errorAbi.inputs], error.data.substring(10));
+			} else if (error.data.startsWith('0x08c379a0')) {
+				// If ABI was not provided, check for the 2 famous errors: 'Error(string)' or 'Panic(uint256)'
+
+				errorName = 'Error';
+				errorSignature = 'Error(string)';
+				// decode abi.inputs according to EIP-838
+				errorArgs = decodeParameters(
+					[
+						{
+							name: 'message',
+							type: 'string',
+						},
+					],
+					error.data.substring(10),
+				);
+			} else if (error.data.startsWith('0x4e487b71')) {
+				errorName = 'Panic';
+				errorSignature = 'Panic(uint256)';
+				// decode abi.inputs according to EIP-838
+				errorArgs = decodeParameters(
+					[
+						{
+							name: 'code',
+							type: 'uint256',
+						},
+					],
+					error.data.substring(10),
+				);
+			} else {
+				console.error('No matching error abi found for error data', error.data);
 			}
 		} catch (err) {
 			console.error(err);
diff --git a/packages/web3-eth-abi/test/fixtures/data.ts b/packages/web3-eth-abi/test/fixtures/data.ts
index 0fe90638f95..f8990a22e86 100644
--- a/packages/web3-eth-abi/test/fixtures/data.ts
+++ b/packages/web3-eth-abi/test/fixtures/data.ts
@@ -974,6 +974,40 @@ export const validDecodeContractErrorData: {
 	input: any[];
 	output: any;
 }[] = [
+	{
+		input: [
+			[],
+			{
+				code: 12,
+				message: 'message',
+				data: '0x08c379a0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000155468697320697320612063616c6c207265766572740000000000000000000000',
+			},
+		],
+		output: {
+			errorName: 'Error',
+			errorSignature: 'Error(string)',
+			errorArgs: {
+				message: 'This is a call revert',
+			},
+		},
+	},
+	{
+		input: [
+			[],
+			{
+				code: 12,
+				message: 'message',
+				data: '0x4e487b71000000000000000000000000000000000000000000000000000000000000002a00000000000000000000000000000000000000000000000000000000000000',
+			},
+		],
+		output: {
+			errorName: 'Panic',
+			errorSignature: 'Panic(uint256)',
+			errorArgs: {
+				code: 42,
+			},
+		},
+	},
 	{
 		input: [
 			[
diff --git a/packages/web3-eth-abi/test/unit/decodeContractErrorData.test.ts b/packages/web3-eth-abi/test/unit/decodeContractErrorData.test.ts
index 3f6a624ef22..9e99add02f3 100644
--- a/packages/web3-eth-abi/test/unit/decodeContractErrorData.test.ts
+++ b/packages/web3-eth-abi/test/unit/decodeContractErrorData.test.ts
@@ -32,7 +32,13 @@ describe('decodeContractErrorData', () => {
 				expect(err.errorName).toEqual(output.errorName);
 				expect(err.errorSignature).toEqual(output.errorSignature);
 				expect(err.errorArgs?.message).toEqual(output.errorArgs?.message);
-				expect(Number(err.errorArgs?.code)).toEqual(output.errorArgs?.code);
+
+				// This ensures they are equal if one was provided
+				// It also skips if both are not provided
+				if (err.errorArgs?.code || output.errorArgs?.code) {
+					// eslint-disable-next-line jest/no-conditional-expect
+					expect(Number(err.errorArgs?.code)).toEqual(output.errorArgs?.code);
+				}
 				expect(err.cause?.code).toEqual(output.cause?.code);
 			},
 		);