ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta Releases feedback issue #923 or our Discord channel.

This is the second beta release towards a final library release, see beta.1 release notes for an overview on the full changes since the last publicly released version.

• Added consensus information to chains, new functions Common.consensusType() for consensus type access ("pow" or "poa") and Common.consensusAlgorithm() to get the associated algorithm or protocol (e.g. "ethash" PoW algorithm or "clique" PoA protocol), see PR #937

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta Releases feedback issue #923 or our Discord channel.

This is the second beta release towards a final library release, see beta.1 release notes for an overview on the full changes since the last publicly released version.

This release introduces new breaking changes, so please carefully read the additional release note sections!

Safe Static Constructor

The library now has an additional safe static constructor Blockchain.create() which awaits the init method and throws if the init method throws:

const common = new Common({ chain: 'ropsten' })
const blockchain = await Blockchain.create({ common })

This is the new recommended way to instantiate a Blockchain object, see PR #930.

Refactored Genesis Block Handling Mechanism

Genesis handling has been reworked to now be safer and reduce the risk of wiping a blockchain by setting a new genesis, see PR #930.

Breaking: The dedicated setGenesisBlock() methods and the optional isGenesis option on Blockchain.putBlock() have been removed. Instead the genesis block is created on initialization either from the Common library instance passed or a custom genesis block passed along with the genesisBlock option. If a custom genesis block is used, this custom block now always has to be passed along on Blockchain initialization, also when operating on an already existing DB.

Changes and Refactoring

• Refactored DBManager with the introduction of an abstract DB operation handling mechanism, if you have modified DBManager in your code this will be a potentially breaking change for you, PR #927
• Renaming of internal variables like Blockchain._headBlock, if you are using these variables in your code this will be a potentially breaking change for you, PR #930
• Made internal _ methods like _saveHeads() private, if you are using these functions in your code this will be a potentially breaking change for you, PR #930
• Improved code documentation, PR #930
• Fixed potential blockchain DB concurrency issues along PR #930

Testing and CI

• Dedicated blockchain reorg test setup and executable test, PR #926
• Breaking: validatePow option has been renamed to validateConsensus to prepare for a future integration of non-PoW (PoA) consensus mechanisms, validateConsensus as well as validateBlocks options now throw when set to true for validation on a non-PoW chain (determined by Common, e.g. 'goerli'), see PR #937

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta Releases feedback issue #923 or our Discord channel.

This is the second beta release towards a final library release, see beta.1 release notes for an overview on the full changes since the last publicly released version.

• Added freeze option to allow for block freeze deactivation (e.g. to allow for subclassing block and adding additional parameters), see PR #941
• Breaking: Difficulty-depending methods canonicalDifficulty() and validateDifficulty() in block and header now throw on non-PoW chains, see PR #937
• Breaking: Non-blockchain dependent validation checks have been extracted from validate() to its own Block.validateData() function. For the validate() method in block and header blockchain is now a mandatory parameter, see PR #942
• Fixed bug where block options have not been passed on to the main constructor from the static factory methods, see PR #941

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta.1 Releases feedback issue #923 or our Discord channel.

New Package Name

Attention! This new version is part of a series of EthereumJS releases all moving to a new scoped package name format. In this case the library is renamed as follows:

• ethereumjs-vm -> @ethereumjs/vm

Please update your library references accordingly or install with:

npm i @ethereumjs/vm

Support for all current Hardforks / HF API Changes

This is the first release of the VM which supports all hardforks currently applied on mainnet starting with the support of the Frontier HF rules all along up to MuirGlacier. 🎉

The following HFs have been added:

• Spurious Dragon, PR #791
• Tangerine Whistle, PR #807
• DAO, PR #843
• Homestead, PR #815
• Frontier, PR #828

A VM with the specific HF rules (on the chain provided) can be instantiated by passing in a Common instance:

import VM from '@ethereumjs/vm'
import Common from '@ethereumjs/common'

const common = new Common({ chain: 'mainnet', hardfork: 'spuriousDragon' })
const vm = new VM({ common })

Breaking: The default HF from the VM has been updated from petersburg to instanbul. The HF setting is now automatically taken from the HF set for Common.DEAULT_HARDFORK, see PR #906.

Breaking: Please note that the options to directly pass in chain and hardfork strings have been removed to simplify the API. Providing a Common instance is now the only way to change the chain setup, see PR #863

Berlin HF Support / HF-independent EIPs

This releases adds support for subroutines (EIP-2315) which gets activated under the berlin HF setting which can now be used as a hardfork instantiation option, see PR #754.

Attention! Berlin HF support is still considered experimental and implementations can change on non-major VM releases!

Support for BLS12-381 precompiles (EIP-2537) is added as an independent EIP implementation - see PR #785 - since there is still an ongoing discussion on taking this EIP in for Berlin or using a more generalized approach on curve computation with the Ethereum EVM (evm384 by the eWASM team).

Another new EIP added is the EIP-2929 with gas cost increases for state access opcodes, see PR #889.

These integrations come along with an API addition to the VM to support the activation of specific EIPs, see PR #856, PR #869 and PR #872.

This API can be used as follows:

import VM from '@ethereumjs/vm'
const vm = new VM({ eips: [2537] })

API Change: New Major Library Versions

The following EthereumJS libraries which are used within the VM internally and can be passed in on instantiation have been updated to new major versions.

• merkle-patricia-tree v3 (VM option state) -> merkle-patricia-tree v4, PR #787
• ethereumjs-blockchain v4-> @ethereumjs/blockchain v5, PR #833
• ethereumjs-common v1 -> @ethereumjs/common v2

Breaking: If you pass in instances of these libraries to the VM please make sure to update these library versions as stated. Please also take a note on the package name changes!

All these libraries are now written in TypeScript and use promises instead of callbacks for accessing their APIs.

New StateManager Interface / StateManager API Changes

There is now a new TypeScript interface for the StateManager, see PR #763. If you are using a custom StateManager you can use this interface to get better assurance that you are using a StateManager which conforms with the current StateManager API and will run in the VM without problems.

The integration of this new interface is highly encouraged since this release also comes with StateManager API changes. Usage of the old ethereumjs-account package (this package will be retired) has been replaced by the new Account class
from the ethereumjs-util package. This affects all Account related StateManager methods, see PR #911.

The Util package also introduces a new Address class. This class replaces all current Buffer inputs on StateManager methods representing an address.

Dual ES5 and ES2017 Builds

We significantly updated our internal tool and CI setup along the work on PR #913 with an update to ESLint from TSLint for code linting and formatting and the introduction of a new build setup.

Packages now target ES2017 for Node.js builds (the main entrypoint from package.json) and introduce a separate ES5 build distributed along using the browser directive as an entrypoint, see PR #921. This will result in performance benefits for Node.js consumers, see here for a releated discussion.

Other Changes

Changes and Refactoring

• Group opcodes based upon hardfork, PR #798
• Split opcodes logic into codes, fns, and utils files, PR #896
• Group precompiles based upon hardfork, PR #783
• Breaking: the step event now emits an ethereumjs-util Account object instead of an ethereumjs-account (package retired) object
• Breaking: NewContractEvent now emits an address of type Address (see ethereumjs-util) instead of a Buffer, PR #919
• Breaking: EVMResult now returns a createdAddress of type Address (see ethereumjs-util) instead of a Buffer, PR #919
• Breaking: RunTxResult now returns a createdAddress of type Address (see ethereumjs-util) instead of a Buffer, PR #919
• Breaking: RunCallOpts now expects origin, caller and to inputs to be of type Address (see ethereumjs-util) instead of a Buffer, PR #919
• Breaking: RunCodeOpts now expects origin, caller and
  address inputs to be of type Address (see ethereumjs-util) instead of a Buffer, PR #919
• Make memory.ts use Buffers instead of Arrays, PR #850
• Use Map for OpcodeList and opcode handlers, PR #852
• Compare buffers directly, PR #851
• Moved gas base fees from VM to Common, PR #806
• Return precompiles on getPrecompile() based on hardfork,
  PR #783
• Removed async dependency, PR #779
• Updated ethereumjs-util to v7, PR #748

CI and Test Improvements

• New benchmarking tool for the VM, CI integration on GitHub actions, PR #794 and PR #830
• Various updates, fixes and refactoring work on the test runner, PR #752 and PR #849
• Integrated ethereumjs-testing code logic into VM for more flexible future test load optimizations, PR #808
• Transition VM tests to TypeScript, PR #881 and PR #882

Bug Fixes

• Fix activatePrecompiles, PR #797
• Strip zeros when putting contract storage in StateManager, PR #880
• Two bug fixes along istanbul SSTORE gas calculation, PR #870

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta.1 Releases feedback issue #923 or our Discord channel.

New Package Name

Attention! This new version is part of a series of EthereumJS releases all moving to a new scoped package name format. In this case the library is renamed as follows:

• ethereumjs-tx -> @ethereumjs/tx

Please update your library references accordingly or install with:

npm i @ethereumjs/tx

Major Refactoring - Breaking Changes

This release is a major refactoring of the transaction library to simplify and strengthen its code base. Refactoring work has been done along PR #812 and PR #887.

New Constructor Params

The constructor used to accept a varying amount of options but now has the following shape:

  Transaction(
    nonce: BN,
    gasPrice: BN,
    gasLimit: BN,
    to: Address | undefined,
    value: BN,
    data: Buffer,
    v?: BN,
    r?: BN,
    s?: BN,
    opts?: TxOptions
  )

Initializing from other data types is assisted with new static factory helpers fromTxData, fromRlpSerializedTx, and fromValuesArray.

Examples:

// Initializing from serialized data
const s1 = tx1.serialize().toString('hex')
const tx = Transaction.fromRlpSerializedTx(toBuffer('0x' + s1))

// Initializing with object
const txData = {
  gasPrice: 1000,
  gasLimit: 10000000,
  value: 42,
}
const tx = Transaction.fromTxData(txData)

// Initializing from array of 0x-prefixed strings.
// First, convert to array of Buffers.
const arr = txFixture.raw.map(toBuffer)
const tx = Transaction.fromValuesArray(arr)

Learn more about the full API in the docs.

Immutability

The returned transaction is now frozen and immutable. To work with a maliable transaction, copy it with const fakeTx = Object.create(tx).

from

The tx.from alias was removed, please use const from = tx.getSenderAddress().

Message to sign

Getting a message to sign has been changed from calling tx.hash(false) to tx.getMessageToSign().

Fake Transaction

The FakeTransaction class was removed since its functionality can now be implemented with less code. To create a fake tansaction for use in e.g. VM.runTx() overwrite getSenderAddress with your own Address. See a full example in the section in the README.

New Default Hardfork

Breaking: The default HF on the library has been updated from petersburg to instanbul, see PR #906.
The HF setting is now automatically taken from the HF set for Common.DEAULT_HARDFORK, see PR #863.

Dual ES5 and ES2017 Builds

We significantly updated our internal tool and CI setup along the work on PR #913 with an update to ESLint from TSLint for code linting and formatting and the introduction of a new build setup.

Packages now target ES2017 for Node.js builds (the main entrypoint from package.json) and introduce a separate ES5 build distributed along using the browser directive as an entrypoint, see PR #921. This will result in performance benefits for Node.js consumers, see here for a releated discussion.

Other Changes

Changes and Refactoring

• Updated ethereumjs-util to v7, PR #748
• Replaced new Buffer() (deprecated) statements with Buffer.from(), PR #721

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta.1 Releases feedback issue #923 or our Discord channel.

New Package Name

Attention! This new version is part of a series of EthereumJS releases all moving to a new scoped package name format. In this case the library is renamed as follows:

• ethashjs -> @ethereumjs/ethash

Please update your library references accordingly or install with:

npm i @ethereumjs/ethash

Library Promisification

The Ethash library has been promisified and callbacks have been removed along PR #833 and preceeding PR #779.

Old API:

ethash.verifyPOW(validblock, (result) => {
  console.log(result)
})

New API:

const result = await ethash.verifyPOW(validBlock)
console.log(result) // => true

See Ethash README for a complete example.

Dual ES5 and ES2017 Builds

We significantly updated our internal tool and CI setup along the work on PR #913 with an update to ESLint from TSLint for code linting and formatting and the introduction of a new build setup.

Packages now target ES2017 for Node.js builds (the main entrypoint from package.json) and introduce a separate ES5 build distributed along using the browser directive as an entrypoint, see PR #921. This will result in performance benefits for Node.js consumers, see here for a releated discussion.

Other Changes

• Updated Block dependency to @ethereumjs/block v3.0.0, PR #883
• Removed async dependency, PR #779

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta.1 Releases feedback issue #923 or our Discord channel.

New Package Name

Attention! This new version is part of a series of EthereumJS releases all moving to a new scoped package name format. In this case the library is renamed as follows:

• ethereumjs-common -> @ethereumjs/common

Please update your library references accordingly or install with:

npm i @ethereumjs/common

New constructor

Breaking: The constructor has been changed to require an options dict to be passed, PR #863

Example:

import Common from '@ethereumjs/common'
const common = new Common({ chain: 'mainnet', hardfork: 'muirGlacier' })

EIP Support

EIPs are now native citizens within the Common library, see PRs #856, #869 and #872. Supported EIPs have their own configuration file like the eips/2537.json file for the BLS precompile EIP and EIP settings can be activated by passing supported EIP numbers to the constructor:

const c = new Common({ chain: 'mainnet', eips: [2537] })

The following EIPs are initially supported within this release:

• EIP-2537 BLS Precompiles
• EIP-2315 EVM Subroutines (PR #876)

EIPs provided are then activated and parameters requested with Common.param() being present in these EIPs take precedence over the setting from the latest hardfork.

There are two new utility functions which return hardfork and EIP values respectively:

• Common.paramByHardfork()
• Common.paramByEIP()

Breaking: It is now not possible any more to pass a dedicated HF setting to Common.param(). Please update your code to explicitly use Common.paramByHardfork() for requesting a parameter for a HF deviating from the HF currently set within your Common instance.

For setting and requesting active EIPs there is Common.setEIPs() and Common.eips() added to the mix.

There is also a new EIP-based hardfork file format which delegates parameter definition to dedicated EIP files (see PR #876). This is in preparation for an upcoming Yolo v2 testnet integration.

Side note: with this new structural setup it gets now possible for all EIPs still implicitly contained within the hardfork files to be extracted as an EIP parameter set within its own dedicated EIP file (which can then be activated via the eip parameter on initialization) without loosing on functionality. If you have a need there feel free to open a PR!

Gas Parameter Completeness for all Hardforks

Remaining gas base fees which still resided in the VM have been moved over to Common along PR #806.
Gas fees for all hardforks up to MuirGlacier are now completely present within the Common library.

Eth/64 Forkhash Support

There is a new Common.forkHash() method returning pre-calculated Forkhash values or alternatively use the internal Common._calcForkHash() implementation to calculate a forkhash on the fly.

Forkhashes are used to uniquely identify a set of hardforks passed to be able to better differentiate between different dedicated chains. This is used for the Eth/64 devp2p protocol update and specificed in EIP-2124 to help improve the devp2p networking stack.

New Block/Hardfork related Utility Functions

The following block and hardfork related utility functions have been added with PRs #863 and #805 respectively:

• setHardforkByBlockNumber() - Sets the hardfork determined by the block number passed
• nextHardforkBlock() - Returns the next HF block for a HF provided or set
• isNextHardforkBlock() - Some convenience additional utility method, matching the existing hardforkBlock() / isHardforkBlock() method setup
• hardforkForForkHash() - Returns the data available for a HF given a specific forkHash

Default Hardfork

The default hardfork has been added as an accessible readonly property DEFAULT_HARDFORK, PR #863. This setting is used starting with the latest major releases of the monorepo libraries like the VM to keep the HF setting in sync across the different libraries.

Current default hardfork is set to istanbul, PR #906.

Dual ES5 and ES2017 Builds

We significantly updated our internal tool and CI setup along the work on PR #913 with an update to ESLint from TSLint for code linting and formatting and the introduction of a new build setup.

Packages now target ES2017 for Node.js builds (the main entrypoint from package.json) and introduce a separate ES5 build distributed along using the browser directive as an entrypoint, see PR #921. This will result in performance benefits for Node.js consumers, see here for a releated discussion.

Other Changes

Changes and Refactoring

• Removed old consensus and finality fields, PR #758
• Removed old casper and sharding fields, PR #762
• Updated ethereumjs-util to v7, PR #748

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta.1 Releases feedback issue #923 or our Discord channel.

New Package Name

Attention! This new version is part of a series of EthereumJS releases all moving to a new scoped package name format. In this case the library is renamed as follows:

• ethereumjs-blockchain -> @ethereumjs/blockchain

Please update your library references accordingly or install with:

npm i @ethereumjs/blockchain

Library Promisification

The Blockchain library has been promisified and callbacks have been removed along PR #833 and preceeding PR
#779.

Old API example:

blockchain.getBlock(blockId, (block) => {
  console.log(block)
})

New API example:

const block = await blockchain.getBlock(blockId)
console.log(block)

See Blockchain README for a complete example.

Constructor API Changes

Constructor options for chain setup on all VM monorepo libraries have been simplified and the plain chain and hardfork options have been removed. Passing in a Common instance is now the single way to switch to a non-default chain (mainnet) or start a blockchain with a higher than chainstart hardfork, see PR #863.

Example:

import Blockchain from '@ethereumjs/blockchain'
const common = new Common({ chain: 'ropsten', hardfork: 'byzantium' })
const blockchain = new Blockchain({ common })

Removed deprecated validate option

The deprecated validate option has been removed, please use valdiateBlock and validatePow for options when instantiating a new Blockchain.

Dual ES5 and ES2017 Builds

We significantly updated our internal tool and CI setup along the work on PR #913 with an update to ESLint from TSLint for code linting and formatting and the introduction of a new build setup.

Packages now target ES2017 for Node.js builds (the main entrypoint from package.json) and introduce a separate ES5 build distributed along using the browser directive as an entrypoint, see PR #921. This will result in performance benefits for Node.js consumers, see here for a releated discussion.

Other Changes

Changes and Refactoring

• Use @ethereumjs/block v3.0.0 block library version, PR #883
• Removed async dependency, PR #779
• Updated ethereumjs-util to v7, PR #748

Bug Fixes

• Fixed blockchain hanging forever in case code throws between a semaphore lock/unlock, Issue #877

ATTENTION: This is a pre-release and only meant to be used for testing purposes.

Do not use in production!

Feedback is extremely welcome, please use the beta.1 Releases feedback issue #923 or our Discord channel.

New Package Name

Attention! This new version is part of a series of EthereumJS releases all moving to a new scoped package name format. In this case the library is renamed as follows:

• ethereumjs-block -> @ethereumjs/block

Please update your library references accordingly or install with:

npm i @ethereumjs/block

TypeScript/Library Import

This is the first TypeScript based release of the library, see PR #72.
The import structure has slightly changed along:

TypeScript

import { BlockHeader } from 'ethereumjs-block'
import { Block } from 'ethereumjs-block'

JavaScript/Node.js

const BlockHeader = require('ethereumjs-block').BlockHeader
const Block = require('ethereumjs-block').Block

The library now also comes with a type declaration file distributed along with the package published.

Major Refactoring - Breaking Changes

This release is a major refactoring of the block library to simplify and strengthen its code base. Refactoring work has been done along PR #72 (Promises) and PR #883 (refactoring of API and internal code structure).

New Constructor Params

The way to instantiate a new BlockHeader or Block object has been completely reworked and is now more explicit, less error prone and produces more TypeScript friendly and readable code.

The old direct constructor usage is now discouraged in favor of different dedicated static factory methods to create new objects.

Breaking: While the main constructors can still be called, signatures changed significantly and your old new Block(...), new BlockHeader(...) instantiations won't work any more and needs to be updated.

BlockHeader Class

There are three new factory methods to create a new BlockHeader:

1. Pass in a Header-attribute named dictionary to BlockHeader.fromHeaderData(headerData: HeaderData = {}, opts: BlockOptions = {}):

const headerData = {
  number: 15,
  parentHash: '0x6bfee7294bf44572b7266358e627f3c35105e1c3851f3de09e6d646f955725a7',
  difficulty: 131072,
  gasLimit: 8000000,
  timestamp: 1562422144,
}
const header = BlockHeader.fromHeaderData(headerData, {})

2. Create a BlockHeader from an RLP-serialized header Buffer with BlockHeader.fromRLPSerializedHeader(serialized: Buffer, opts: BlockOptions).

const serialized = Buffer.from(
  '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',
  'hex',
)
const header = BlockHeader.fromRLPSerializedHeader(serialized, {})

3. Create a BlockHeader from an array of Buffer values, you can do a first short roundtrip test with:

const valuesArray = header.raw()
BlockHeader.fromValuesArray(valuesArray, {})

Generally internal types representing block header values are now closer to their domain representation (number, difficulty, gasLimit) instead of having everthing represented as a Buffer.

Block Class

There are analogue new static factories for the Block class:

• Block.fromBlockData(blockData: BlockData = {}, opts: BlockOptions = {})
• Block.fromRLPSerializedBlock(serialized: Buffer, opts: BlockOptions = {})
• Block.fromValuesArray(values: BlockBuffer, opts: BlockOptions = {})

Learn more about the full API in the docs.

Immutability

The returned block is now frozen and immutable. To work with a maliable block, copy it with const fakeBlock = Object.create(block).

Promise-based API

The API of this library is now completely promise-based and the old callback-style interface has been dropped.

This affects the following methods of the API now being defined as async and returning a Promise:

Header Class

• BlockHeader.validate(blockchain: Blockchain, height?: BN): Promise<void>

Block Class

• Block.genTxTrie(): Promise<void>
• Block.validate(blockChain: Blockchain): Promise<void>
• Block.validateUncles(blockchain: Blockchain): Promise<void>

Usage example:

try {
  await block.validate(blockchain)
  // Block validation has passed
} catch (err) {
  // handle errors appropriately
}

Header Validation Methods > Signature Changes

Breaking: The signatures of the following header validation methods have been updated to take a parentBlockHeader instead of a
parentBlock input parameter for consistency and removing a circling dependency with Block:

• BlockHeader.canonicalDifficulty(parentBlockHeader: BlockHeader): BN
• BlockHeader.validateDifficulty(parentBlockHeader: BlockHeader): boolean
• BlockHeader.validateGasLimit(parentBlockHeader: BlockHeader): boolean

On the Block library new corresponding methods have been added which both operate on a block instance and expect a parentBlock as an input parameter.

New Default Hardfork

Breaking: The default HF on the library has been updated from petersburg to instanbul, see PR #906.
The HF setting is now automatically taken from the HF set for Common.DEAULT_HARDFORK, see PR #863.

Dual ES5 and ES2017 Builds

We significantly updated our internal tool and CI setup along the work on PR #913 with an update to ESLint from TSLint for code linting and formatting and the introduction of a new build setup.

Packages now target ES2017 for Node.js builds (the main entrypoint from package.json) and introduce a separate ES5 build distributed along using the browser directive as an entrypoint, see PR #921. This will result in performance benefits for Node.js consumers, see here for a releated discussion.

Other Changes

Features

• Added Block.genesis() and BlockHeader.genesis() aliases to create a genesis block or header, PR #883
• Added DAO hardfork support (check for extraData attribute if DAO HF is active), PR #843

Changes and Refactoring

• Added Node 10, 12 support, dropped Node 7 support, PR #72
• Passing in a blockchain is now optional on Block.validate(), PR #883
• Breaking: Block.validateTransactions(stringError: true) now returns a string[], PR #883
• Breaking: Decoupling of the Block.serialize() and Block.raw() methods, Block.serialize() now always returns the RLP-encoded block (signature change!), Block.raw() always returns the pure Buffer array, PR #883
• Breaking: Block.toJSON() now always returns the labeled JSON representation, removal of the labeled function parameter, PR #883
• Updated merkle-patricia-tree dependency to v4, PR #787
• Updated ethereumjs-util dependency to v7, PR #748
• Removal of the async dependency, PR #72

CI and Testing

• Browser test run on CI, PR #72
• Karma browser test run config modernization and simplification PR #72
• Updated test source files to TypeScript, PR #72

Bug Fixes

• Signature fix for pre-homestead blocks, PR #67

This release replaces the tiled (~) dependency from ethereumjs-util for a caret (^) one, meaning that any update to ethereumjs-util v6 will also be available for this library.