Implement evaluation from external registry

package.json

@@ -41,7 +41,8 @@
     "coveralls": "^3.0.0",
     "documentation": "^9.0.0-alpha.0",
     "nyc": "^11.3.0",
-    "standard": "^12.0.1"
+    "standard": "^12.0.1",
+    "yargs": "^13.1.0"
   },
   "dependencies": {
     "@babel/runtime": "^7.1.2",

scripts/inspect

@@ -0,0 +1,55 @@
+#!/usr/bin/env node
+
+const yargs = require('yargs')
+const fs = require('fs')
+const path = require('path')
+const Eth = require('web3-eth')
+
+const { evaluateWithRegistry } = require('../dist')
+
+const NETWORKS = {
+  rinkeby: 'https://rinkeby.eth.aragon.network',
+  mainnet: 'https://mainnet.eth.aragon.network',
+}
+
+const exec = async (argv) => {
+  const { network } = argv
+  const [ txHash ] = argv._
+
+  const rpc = NETWORKS[network]
+
+  if (!rpc) {
+    throw new Error(`Unsupported network '${network}'`)
+  }
+
+  const eth = new Eth(rpc)
+
+  console.log(`Fetching ${network} for ${txHash}`)
+  const {
+    to,
+    from,
+    blockNumber,
+    input: data
+  } = await eth.getTransaction(txHash)
+
+  const description = await evaluateWithRegistry({ transaction: { to, data }})
+
+  console.log(`Transaction from ${from} to ${to} in block ${blockNumber}:\n`)
+  console.log(description ? `🔥 ${description} 🔥` : 'Unknown 😢')
+}
+
+exec(
+  yargs
+    .usage('Usage: $0 [txid]')
+    .option('network', {
+      alias: 'n',
+      default: 'mainnet',
+      describe: 'Output path to radspec db file',
+      type: 'string',
+    })
+    .argv
+  )
+  .catch(err => {
+    console.error(err)
+    process.exit(1)
+  })

src/extract.js

@@ -0,0 +1,91 @@
+const fs = require('fs')
+const { promisify } = require('util')
+const readFile = promisify(fs.readFile)
+
+const modifiesStateAndIsPublic = declaration =>
+  !declaration.match(/\b(internal|private|view|pure|constant)\b/)
+
+const typeOrAddress = type => {
+  const types = ['address', 'byte', 'uint', 'int', 'bool', 'string']
+
+  // check if the type starts with any of the above types, otherwise it is probably
+  // a typed contract, so we need to return address for the signature
+  return types.filter(t => type.indexOf(t) === 0).length > 0 ? type : 'address'
+}
+
+// extracts function signature from function declaration
+const getSignature = declaration => {
+  let [name, params] = declaration.match(/function ([^]*?)\)/)[1].split('(')
+
+  if (!name) {
+    return 'fallback'
+  }
+
+  let argumentNames = []
+
+  if (params) {
+    // Has parameters
+    const inputs = params
+      .replace(/\n/gm, '')
+      .replace(/\t/gm, '')
+      .split(',')
+
+    params = inputs
+      .map(param => param.split(' ').filter(s => s.length > 0)[0])
+      .map(type => typeOrAddress(type))
+      .join(',')
+
+    argumentNames = inputs.map(param => param.split(' ').filter(s => s.length > 0)[1] || '')
+  }
+
+  return { sig: `${name}(${params})`, argumentNames }
+}
+
+const getNotice = declaration => {
+  // capture from @notice to either next '* @' or end of comment '*/'
+  const notices = declaration.match(/(@notice)([^]*?)(\* @|\*\/)/m)
+  if (!notices || notices.length === 0) return null
+
+  return notices[0]
+    .replace('*/', '')
+    .replace('* @', '')
+    .replace('@notice ', '')
+    .replace(/\n/gm, '')
+    .replace(/\t/gm, '')
+    .split(' ')
+    .filter(x => x.length > 0)
+    .join(' ')
+}
+
+// extracts required role from function declaration
+const getRoles = declaration => {
+  const auths = declaration.match(/auth.?\(([^]*?)\)/gm)
+  if (!auths) return []
+
+  return auths.map(
+    authStatement =>
+      authStatement
+        .split('(')[1]
+        .split(',')[0]
+        .split(')')[0]
+  )
+}
+
+// Takes the path to a solidity file and extracts public function signatures,
+// its auth role if any and its notice statement
+module.exports = async sourceCodePath => {
+  const sourceCode = await readFile(sourceCodePath, 'utf8')
+
+  // everything between every 'function' and '{' and its @notice
+  const funcDecs = sourceCode.match(/(@notice|^\s*function)(?:[^]*?){/gm)
+
+  if (!funcDecs) return []
+
+  return funcDecs
+    .filter(dec => modifiesStateAndIsPublic(dec))
+    .map(dec => ({
+        roles: getRoles(dec),
+        notice: getNotice(dec),
+        ...getSignature(dec),
+    }))
+}

src/index.js

@@ -11,6 +11,7 @@
  * @module radspec
  */
 import ABI from 'web3-eth-abi'
+import MetadataDAO from 'metadata-dao'
 import { defaultHelpers } from './helpers'
 import { evaluateRaw } from './lib'
 
@@ -93,9 +94,60 @@ function evaluate (source, call, { userHelpers = {}, ...options } = {}) {
   )
 }
 
+async function evaluateWithRegistry (call, { userHelpers = {}, ...options } = {}) {
+  const metadataDAO = new MetadataDAO()
+
+  // Get method ID
+  const { to, data } = call.transaction
+  const methodId = data.substr(0, 10)
+
+  const fn = await metadataDAO.query('radspec', 'sig', methodId)
+
+  if (!fn) {
+    return null
+  }
+
+  // If the function was found in local radspec registry. Decode and evaluate.
+  const { notice: source, signature: sig } = fn
+
+  // get the array of input types from the function signature
+  const inputString = sig.replace(')', '').split('(')[1]
+
+  let parameters = []
+
+  // If the function has parameters
+  if (inputString !== '') {
+    const inputs = inputString.split(',')
+
+    // Decode parameters
+    const parameterValues = ABI.decodeParameters(inputs, '0x' + data.substr(10))
+    parameters = inputs.reduce((acc, input, i) => (
+      {
+        [`$${i + 1}`]: {
+          type: input,
+          value: parameterValues[i]
+        },
+        ...acc
+      }), {})
+  }
+
+  const availableHelpers = { ...defaultHelpers, ...userHelpers }
+
+  return await evaluateRaw(
+    source,
+    parameters,
+    {
+      ...options,
+      availableHelpers,
+      to: call.transaction.to
+    }
+  )
+}
+
 export default evaluate
-export { evaluate, evaluateRaw }
+export { evaluate, evaluateRaw, evaluateWithRegistry }
 
 // Re-export some commonly used inner functionality
 export { parse } from './parser'
 export { scan } from './scanner'
+