Correct EIP-712 encoding (#11092)

* support encoding custom array types as fields

* new line

* removed expect

* Update util/EIP-712/src/encode.rs

Co-Authored-By: Andronik Ordian <write@reusable.software>

* bump lunarity

* update cargo lock

* nits

* nits

Cargo.lock

@@ -815,13 +815,12 @@ dependencies = [
  "itertools 0.7.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "keccak-hash 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "lunarity-lexer 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lunarity-lexer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.89 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
- "toolshed 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "validator 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "validator_derive 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2456,6 +2455,27 @@ dependencies = [
  "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "logos"
+version = "0.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "logos-derive 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "toolshed 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "logos-derive"
+version = "0.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "lru-cache"
 version = "0.1.2"
@@ -2466,10 +2486,10 @@ dependencies = [
 
 [[package]]
 name = "lunarity-lexer"
-version = "0.1.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "toolshed 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "logos 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -4704,7 +4724,7 @@ dependencies = [
 
 [[package]]
 name = "toolshed"
-version = "0.4.0"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4905,6 +4925,11 @@ dependencies = [
 name = "using_queue"
 version = "0.1.0"
 
+[[package]]
+name = "utf8-ranges"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "validator"
 version = "0.8.0"
@@ -5377,8 +5402,10 @@ dependencies = [
 "checksum lock_api 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ed946d4529956a20f2d63ebe1b69996d5a2137c91913fe3ebbeff957f5bca7ff"
 "checksum lock_api 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f8912e782533a93a167888781b836336a6ca5da6175c05944c86cf28c31104dc"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
+"checksum logos 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)" = "60ca690691528b32832c7e8aaae8ae1edcdee4e9ffde55b2d31a4795bc7a12d0"
+"checksum logos-derive 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)" = "917dccdd529d5681f3d28b26bcfdafd2ed67fe4f26d15b5ac679f67b55279f3d"
 "checksum lru-cache 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "31e24f1ad8321ca0e8a1e0ac13f23cb668e6f5466c2c57319f6a5cf1cc8e3b1c"
-"checksum lunarity-lexer 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8a1670671f305792567116d4660e6e5bd785d6fa973e817c3445c0a7a54cecb6"
+"checksum lunarity-lexer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "28a5446c03ed5bd4ae2cca322c4c84d9bd9741b6788f75c404719474cb63d3b7"
 "checksum malloc_size_of_derive 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "35adee9ed962cf7d07d62cb58bc45029f3227f5b5b86246caa8632f06c187bc3"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 "checksum memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "88579771288728879b57485cc7d6b07d648c9f0141eb955f8ab7f9d45394468e"
@@ -5559,7 +5586,7 @@ dependencies = [
 "checksum tokio-uds 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "22e3aa6d1fcc19e635418dc0a30ab5bd65d347973d6f43f1a37bf8d9d1335fc9"
 "checksum toml 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "758664fc71a3a69038656bee8b6be6477d2a6c315a6b81f7081f591bffa4111f"
 "checksum toml 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b8c96d7873fa7ef8bdeb3a9cda3ac48389b4154f32b9803b4bc26220b677b039"
-"checksum toolshed 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "450441e131c7663af72e63a33c02a6a1fbaaa8601dc652ed6757813bb55aeec7"
+"checksum toolshed 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "54a272adbf14cfbb486774d09ee3e00c38d488cd390084a528f70e10e3a184a8"
 "checksum trace-time 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dbe82f2f0bf1991e163e757baf044282823155dd326e70f44ce2186c3c320cc9"
 "checksum transaction-pool 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "454adc482e32785c3beab9415dd0f3c689f29cc2d16717eb62f6a784d53544b4"
 "checksum transient-hashmap 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "aeb4b191d033a35edfce392a38cdcf9790b6cebcb30fa690c312c29da4dc433e"
@@ -5580,6 +5607,7 @@ dependencies = [
 "checksum unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "382810877fe448991dfc7f0dd6e3ae5d58088fd0ea5e35189655f84e6814fa56"
 "checksum untrusted 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "55cd1f4b4e96b46aeb8d4855db4a7a9bd96eeeb5c6a1ab54593328761642ce2f"
 "checksum url 1.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2a321979c09843d272956e73700d12c4e7d3d92b2ee112b31548aef0d4efc5a6"
+"checksum utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b4ae116fef2b7fea257ed6440d3cfcff7f190865f170cdad00bb6465bf18ecba"
 "checksum validator 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "236a5eda3df2c877872e98dbc55d497d943792e6405d8fc65bd4f8a5e3b53c99"
 "checksum validator_derive 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d360d6f5754972c0c1da14fb3d5580daa31aee566e1e45e2f8d3bf5950ecd3e9"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"

util/EIP-712/Cargo.toml

@@ -20,10 +20,9 @@ ethereum-types = "0.6.0"
 failure = "0.1"
 itertools = "0.7"
 lazy_static = "1.1"
-toolshed = "0.4"
 regex = "1.0"
 validator = "0.8"
 validator_derive = "0.8"
-lunarity-lexer = "0.1"
+lunarity-lexer = "0.2"
 rustc-hex = "2.0"
 indexmap = "1.0.2"

util/EIP-712/src/encode.rs

@@ -23,7 +23,7 @@ use std::str::FromStr;
 use itertools::Itertools;
 use indexmap::IndexSet;
 use serde_json::to_value;
-use crate::parser::{Parser, Type};
+use crate::parser::{parse_type, Type};
 use crate::error::{Result, ErrorKind, serde_error};
 use crate::eip712::{EIP712, MessageTypes};
 use rustc_hex::FromHex;
@@ -56,11 +56,16 @@ fn build_dependencies<'a>(message_type: &'a str, message_types: &'a MessageTypes
 			deps.insert(item);
 
 			for field in fields {
+				// check if this field is an array type
+				let field_type = if let Some(index) = field.type_.find('[') {
+					&field.type_[..index]
+				} else {
+					&field.type_
+				};
 				// seen this type before? or not a custom type skip
-				if deps.contains(&*field.type_) || !message_types.contains_key(&*field.type_) {
+				if !deps.contains(field_type) || message_types.contains_key(field_type) {
-					continue;
+					types.insert(field_type);
 				}
-				types.insert(&*field.type_);
 			}
 		}
 	};
@@ -70,7 +75,8 @@ fn build_dependencies<'a>(message_type: &'a str, message_types: &'a MessageTypes
 
 fn encode_type(message_type: &str, message_types: &MessageTypes) -> Result<String> {
 	let deps = {
-		let mut temp = build_dependencies(message_type, message_types).ok_or_else(|| ErrorKind::NonExistentType)?;
+		let mut temp = build_dependencies(message_type, message_types)
+			.ok_or(ErrorKind::NonExistentType)?;
 		temp.remove(message_type);
 		let mut temp = temp.into_iter().collect::<Vec<_>>();
 		(&mut temp[..]).sort_unstable();
@@ -99,7 +105,6 @@ fn type_hash(message_type: &str, typed_data: &MessageTypes) -> Result<H256> {
 }
 
 fn encode_data(
-	parser: &Parser,
 	message_type: &Type,
 	message_types: &MessageTypes,
 	value: &Value,
@@ -112,17 +117,25 @@ fn encode_data(
 			length
 		} => {
 			let mut items = vec![];
-			let values = value.as_array().ok_or_else(|| serde_error("array", field_name))?;
+			let values = value.as_array()
+				.ok_or(serde_error("array", field_name))?;
 
 			// check if the type definition actually matches
 			// the length of items to be encoded
 			if length.is_some() && Some(values.len() as u64) != *length {
 				let array_type = format!("{}[{}]", *inner, length.unwrap());
-				return Err(ErrorKind::UnequalArrayItems(length.unwrap(), array_type, values.len() as u64))?
+				return Err(
+					ErrorKind::UnequalArrayItems(length.unwrap(), array_type, values.len() as u64)
+				)?
 			}
 
 			for item in values {
-				let mut encoded = encode_data(parser, &*inner, &message_types, item, field_name)?;
+				let mut encoded = encode_data(
+					&*inner,
+					&message_types,
+					item,
+					field_name
+				)?;
 				items.append(&mut encoded);
 			}
 
@@ -135,8 +148,13 @@ fn encode_data(
 
 			for field in message_types.get(ident).expect("Already checked in match guard; qed") {
 				let value = &value[&field.name];
-				let type_ = parser.parse_type(&*field.type_)?;
+				let type_ = parse_type(&*field.type_)?;
-				let mut encoded = encode_data(parser, &type_, &message_types, &value, Some(&*field.name))?;
+				let mut encoded = encode_data(
+					&type_,
+					&message_types,
+					&value,
+					Some(&*field.name)
+				)?;
 				tokens.append(&mut encoded);
 			}
 
@@ -144,7 +162,8 @@ fn encode_data(
 		}
 
 		Type::Bytes => {
-			let string = value.as_str().ok_or_else(|| serde_error("string", field_name))?;
+			let string = value.as_str()
+				.ok_or(serde_error("string", field_name))?;
 
 			check_hex(&string)?;
 
@@ -157,7 +176,8 @@ fn encode_data(
 		}
 
 		Type::Byte(_) => {
-			let string = value.as_str().ok_or_else(|| serde_error("string", field_name))?;
+			let string = value.as_str()
+				.ok_or(serde_error("string", field_name))?;
 
 			check_hex(&string)?;
 
@@ -169,28 +189,34 @@ fn encode_data(
 		}
 
 		Type::String => {
-			let value = value.as_str().ok_or_else(|| serde_error("string", field_name))?;
+			let value = value.as_str()
+				.ok_or(serde_error("string", field_name))?;
 			let hash = keccak(value).as_ref().to_vec();
 			encode(&[EthAbiToken::FixedBytes(hash)])
 		}
 
-		Type::Bool => encode(&[EthAbiToken::Bool(value.as_bool().ok_or_else(|| serde_error("bool", field_name))?)]),
+		Type::Bool => encode(&[EthAbiToken::Bool(value.as_bool()
+			.ok_or(serde_error("bool", field_name))?)]),
 
 		Type::Address => {
-			let addr = value.as_str().ok_or_else(|| serde_error("string", field_name))?;
+			let addr = value.as_str()
+				.ok_or(serde_error("string", field_name))?;
 			if addr.len() != 42 {
 				return Err(ErrorKind::InvalidAddressLength(addr.len()))?;
 			}
-			let address = EthAddress::from_str(&addr[2..]).map_err(|err| ErrorKind::HexParseError(format!("{}", err)))?;
+			let address = EthAddress::from_str(&addr[2..])
+				.map_err(|err| ErrorKind::HexParseError(format!("{}", err)))?;
 			encode(&[EthAbiToken::Address(address)])
 		}
 
 		Type::Uint | Type::Int => {
-			let string = value.as_str().ok_or_else(|| serde_error("int/uint", field_name))?;
+			let string = value.as_str()
+				.ok_or(serde_error("int/uint", field_name))?;
 
 			check_hex(&string)?;
 
-			let uint = U256::from_str(&string[2..]).map_err(|err| ErrorKind::HexParseError(format!("{}", err)))?;
+			let uint = U256::from_str(&string[2..])
+				.map_err(|err| ErrorKind::HexParseError(format!("{}", err)))?;
 
 			let token = if *message_type == Type::Uint {
 				EthAbiToken::Uint(uint)
@@ -200,7 +226,12 @@ fn encode_data(
 			encode(&[token])
 		}
 
-		_ => return Err(ErrorKind::UnknownType(format!("{}", field_name.unwrap_or("")), format!("{}", *message_type)))?
+		_ => return Err(
+			ErrorKind::UnknownType(
+				format!("{}", field_name.unwrap_or("")),
+				format!("{}", *message_type)
+			).into()
+		)
 	};
 
 	Ok(encoded)
@@ -213,10 +244,19 @@ pub fn hash_structured_data(typed_data: EIP712) -> Result<H256> {
 	// EIP-191 compliant
 	let prefix = (b"\x19\x01").to_vec();
 	let domain = to_value(&typed_data.domain).unwrap();
-	let parser = Parser::new();
 	let (domain_hash, data_hash) = (
-		encode_data(&parser, &Type::Custom("EIP712Domain".into()), &typed_data.types, &domain, None)?,
+		encode_data(
-		encode_data(&parser, &Type::Custom(typed_data.primary_type), &typed_data.types, &typed_data.message, None)?
+			&Type::Custom("EIP712Domain".into()),
+			&typed_data.types,
+			&domain,
+			None
+		)?,
+		encode_data(
+			&Type::Custom(typed_data.primary_type),
+			&typed_data.types,
+			&typed_data.message,
+			None
+		)?
 	);
 	let concat = [&prefix[..], &domain_hash[..], &data_hash[..]].concat();
 	Ok(keccak(concat))
@@ -412,4 +452,196 @@ mod tests {
 			ErrorKind::UnequalArrayItems(2, "Person[2]".into(), 1)
 		)
 	}
+
+	#[test]
+	fn test_typed_data_v4() {
+		let string = r#"{
+            "types": {
+                "EIP712Domain": [
+                    {
+                      "name": "name",
+                      "type": "string"
+                    },
+                    {
+                      "name": "version",
+                      "type": "string"
+                    },
+                    {
+                      "name": "chainId",
+                      "type": "uint256"
+                    },
+                    {
+                      "name": "verifyingContract",
+                      "type": "address"
+                    }
+                ],
+                "Person": [
+                    {
+                      "name": "name",
+                      "type": "string"
+                    },
+                    {
+                      "name": "wallets",
+                      "type": "address[]"
+                    }
+                ],
+                "Mail": [
+                    {
+                      "name": "from",
+                      "type": "Person"
+                    },
+                    {
+                      "name": "to",
+                      "type": "Person[]"
+                    },
+                    {
+                      "name": "contents",
+                      "type": "string"
+                    }
+                ],
+                "Group": [
+                    {
+                      "name": "name",
+                      "type": "string"
+                    },
+                    {
+                      "name": "members",
+                      "type": "Person[]"
+                    }
+                ]
+            },
+            "domain": {
+                "name": "Ether Mail",
+                "version": "1",
+                "chainId": "0x1",
+                "verifyingContract": "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"
+            },
+            "primaryType": "Mail",
+            "message": {
+                "from": {
+                    "name": "Cow",
+                    "wallets": [
+                      "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826",
+                      "0xDeaDbeefdEAdbeefdEadbEEFdeadbeEFdEaDbeeF"
+                    ]
+                },
+                "to": [
+                    {
+                        "name": "Bob",
+                        "wallets": [
+                            "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB",
+                            "0xB0BdaBea57B0BDABeA57b0bdABEA57b0BDabEa57",
+                            "0xB0B0b0b0b0b0B000000000000000000000000000"
+                        ]
+                    }
+                ],
+                "contents": "Hello, Bob!"
+            }
+        }"#;
+
+		let typed_data = from_str::<EIP712>(string).expect("alas error!");
+		let hash = hash_structured_data(typed_data.clone()).expect("alas error!");
+		assert_eq!(
+			&format!("{:x}", hash)[..],
+
+			"a85c2e2b118698e88db68a8105b794a8cc7cec074e89ef991cb4f5f533819cc2",
+		);
+	}
+
+	#[test]
+	fn test_typed_data_v4_custom_array() {
+		let string = r#"{
+            "types": {
+                "EIP712Domain": [
+                    {
+                        "name": "name",
+                        "type": "string"
+                    },
+                    {
+                        "name": "version",
+                        "type": "string"
+                    },
+                    {
+                        "name": "chainId",
+                        "type": "uint256"
+                    },
+                    {
+                        "name": "verifyingContract",
+                        "type": "address"
+                    }
+                ],
+              "Person": [
+                {
+                  "name": "name",
+                  "type": "string"
+                },
+                {
+                  "name": "wallets",
+                  "type": "address[]"
+                }
+              ],
+              "Mail": [
+                {
+                  "name": "from",
+                  "type": "Person"
+                },
+                {
+                  "name": "to",
+                  "type": "Group"
+                },
+                {
+                  "name": "contents",
+                  "type": "string"
+                }
+              ],
+              "Group": [
+                {
+                  "name": "name",
+                  "type": "string"
+                },
+                {
+                  "name": "members",
+                  "type": "Person[]"
+                }
+              ]
+            },
+            "domain": {
+              "name": "Ether Mail",
+              "version": "1",
+              "chainId": "0x1",
+              "verifyingContract": "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"
+            },
+            "primaryType": "Mail",
+            "message": {
+              "from": {
+                "name": "Cow",
+                "wallets": [
+                  "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826",
+                  "0xDeaDbeefdEAdbeefdEadbEEFdeadbeEFdEaDbeeF"
+                ]
+              },
+              "to": {
+                "name": "Farmers",
+                "members": [
+                  {
+                    "name": "Bob",
+                    "wallets": [
+                      "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB",
+                      "0xB0BdaBea57B0BDABeA57b0bdABEA57b0BDabEa57",
+                      "0xB0B0b0b0b0b0B000000000000000000000000000"
+                    ]
+                  }
+                ]
+              },
+              "contents": "Hello, Bob!"
+            }
+          }"#;
+		let typed_data = from_str::<EIP712>(string).expect("alas error!");
+		let hash = hash_structured_data(typed_data.clone()).expect("alas error!");
+
+		assert_eq!(
+			&format!("{:x}", hash)[..],
+			"cd8b34cd09c541cfc0a2fcd147e47809b98b335649c2aa700db0b0c4501a02a0",
+		);
+	}
 }

util/EIP-712/src/parser.rs

@@ -17,7 +17,6 @@
 //! Solidity type-name parsing
 use lunarity_lexer::{Lexer, Token};
 use crate::error::*;
-use toolshed::Arena;
 use std::{fmt, result};
 
 #[derive(Debug, Clone, PartialEq)]
@@ -68,23 +67,13 @@ impl fmt::Display for Type {
 	}
 }
 
-pub struct Parser {
-	arena: Arena,
-}
-
-impl Parser {
-	pub fn new() -> Self {
-		Parser {
-			arena: Arena::new()
-		}
-	}
 
 /// the type string is being validated before it's parsed.
-	pub fn parse_type(&self, field_type: &str) -> Result<Type> {
+pub fn parse_type(field_type: &str) -> Result<Type> {
 	#[derive(PartialEq)]
 	enum State { Open, Close }
 
-		let mut lexer = Lexer::new(&self.arena, field_type);
+	let mut lexer = Lexer::new(field_type);
 	let mut token = None;
 	let mut state = State::Close;
 	let mut array_depth = 0;
@@ -92,8 +81,8 @@ impl Parser {
 
 	while lexer.token != Token::EndOfProgram {
 		let type_ = match lexer.token {
-				Token::Identifier => Type::Custom(lexer.token_as_str().to_owned()),
+			Token::Identifier => Type::Custom(lexer.slice().to_owned()),
-				Token::TypeByte => Type::Byte(lexer.type_size.0),
+			Token::TypeByte => Type::Byte(lexer.extras.0),
 			Token::TypeBytes => Type::Bytes,
 			Token::TypeBool => Type::Bool,
 			Token::TypeUint => Type::Uint,
@@ -101,20 +90,20 @@ impl Parser {
 			Token::TypeString => Type::String,
 			Token::TypeAddress => Type::Address,
 			Token::LiteralInteger => {
-					let length = lexer.token_as_str();
+				let length = lexer.slice();
 				current_array_length = Some(length
 					.parse()
 					.map_err(|_|
 						ErrorKind::InvalidArraySize(length.into())
 					)?
 				);
-					lexer.consume();
+				lexer.advance();
 				continue;
-				},
+			}
 			Token::BracketOpen if token.is_some() && state == State::Close => {
 				state = State::Open;
-					lexer.consume();
+				lexer.advance();
-					continue
+				continue;
 			}
 			Token::BracketClose if array_depth < 10 => {
 				if state == State::Open && token.is_some() {
@@ -122,27 +111,26 @@ impl Parser {
 					state = State::Close;
 					token = Some(Type::Array {
 						inner: Box::new(token.expect("if statement checks for some; qed")),
-							length
+						length,
 					});
-						lexer.consume();
+					lexer.advance();
 					array_depth += 1;
-						continue
+					continue;
 				} else {
-						return Err(ErrorKind::UnexpectedToken(lexer.token_as_str().to_owned(), field_type.to_owned()))?
+					return Err(ErrorKind::UnexpectedToken(lexer.slice().to_owned(), field_type.to_owned()))?;
 				}
 			}
 			Token::BracketClose if array_depth == 10 => {
-					return Err(ErrorKind::UnsupportedArrayDepth)?
+				return Err(ErrorKind::UnsupportedArrayDepth)?;
 			}
-				_  => return Err(ErrorKind::UnexpectedToken(lexer.token_as_str().to_owned(), field_type.to_owned()))?
+			_ => return Err(ErrorKind::UnexpectedToken(lexer.slice().to_owned(), field_type.to_owned()))?
 		};
 
 		token = Some(type_);
-			lexer.consume();
+		lexer.advance();
 	}
 
-		Ok(token.ok_or_else(|| ErrorKind::NonExistentType)?)
+	Ok(token.ok_or(ErrorKind::NonExistentType)?)
-	}
 }
 
 #[cfg(test)]
@@ -151,22 +139,19 @@ mod tests {
 
 	#[test]
 	fn test_parser() {
-		let parser = Parser::new();
 		let source = "byte[][][7][][][][][][][]";
-		parser.parse_type(source).unwrap();
+		parse_type(source).unwrap();
 	}
 
 	#[test]
 	fn test_nested_array() {
-		let parser = Parser::new();
 		let source = "byte[][][7][][][][][][][][]";
-		assert_eq!(parser.parse_type(source).is_err(), true);
+		assert_eq!(parse_type(source).is_err(), true);
 	}
 
 	#[test]
 	fn test_malformed_array_type() {
-		let parser = Parser::new();
 		let source = "byte[7[]uint][]";
-		assert_eq!(parser.parse_type(source).is_err(), true)
+		assert_eq!(parse_type(source).is_err(), true)
 	}
 }