nim-ethers/testmodule/testErrorDecoding.nim

56 lines
2.0 KiB
Nim

import std/unittest
import std/strutils
import pkg/questionable/results
import pkg/contractabi
import pkg/ethers/errors
suite "Decoding of custom errors":
type
SimpleError = object of SolidityError
ErrorWithArguments = object of SolidityError
arguments: tuple[one: UInt256, two: bool]
test "decodes a simple error":
let decoded = SimpleError.decode(@[0xc2'u8, 0xbb, 0x94, 0x7c])
check decoded is ?!(ref SimpleError)
check decoded.isSuccess
check (!decoded).msg.contains("SimpleError()")
test "decodes error with arguments":
let expected = (ref ErrorWithArguments)(arguments: (1.u256, true))
let encoded = AbiEncoder.encode(expected)
let decoded = ErrorWithArguments.decode(encoded)
check decoded.isSuccess
check (!decoded).arguments.one == 1.u256
check (!decoded).arguments.two == true
check (!decoded).msg.contains("ErrorWithArguments(one: 1, two: true)")
test "returns failure when decoding fails":
let invalid = @[0xc2'u8, 0xbb, 0x94, 0x0] # last byte is wrong
let decoded = SimpleError.decode(invalid)
check decoded.isFailure
test "returns failure when data is less than 4 bytes":
let invalid = @[0xc2'u8, 0xbb, 0x94]
let decoded = SimpleError.decode(invalid)
check decoded.isFailure
test "returns failure when there are trailing bytes":
let invalid = @[0xc2'u8, 0xbb, 0x94, 0x7c, 0x0] # one byte too many
let decoded = SimpleError.decode(invalid)
check decoded.isFailure
test "returns failure when there are trailing bytes after arguments":
let error = (ref ErrorWithArguments)(arguments: (1.u256, true))
let encoded = AbiEncoder.encode(error)
let invalid = encoded & @[0x0'u8] # one byte too many
let decoded = ErrorWithArguments.decode(invalid)
check decoded.isFailure
test "decoding only works for SolidityErrors":
type InvalidError = ref object of CatchableError
const works = compiles:
InvalidError.decode(@[0x1'u8, 0x2, 0x3, 0x4])
check not works