ethjs-query new BlockTracker({ provider })

// // public //

getCurrentBlock() start() stop()

EVENTS

block <-- every block in order fork <-- common root of fork force <-- latest block was forced latest <-- the latest block, possibly skipping blocks

// // private //

async _performSync() { const latestBlock = await this._fetchLatestBlock() return this._considerBlock(latestBlock) }

async _considerBlock(newBlock) { const currentBlock = this.getCurrentBlock() // check if new block should be head if (!difficultyLessThan(currentBlock, newBlock)) { return Promise.resolve() } const blockPath = await _fetchPathBetweenBlocks(currentBlock, newBlock) }

_fetchPathBetweenBlocks (startBlock, endBlock) { // walk from end to start }

_fetchLatestBlock

_fetchBlockByHash

_fetchBlockByTag

poll latest, walk back to current block, abort if too far? ignore if 'latest' if less difficulty