Merge pull request #501 from mrfelton/refactor/hadle-grpc-startup-errors

feat(grpc): lnd connection error recovery

app/components/Onboarding/ConnectionDetails.js

@@ -8,45 +8,57 @@ const ConnectionDetails = ({
   connectionMacaroon,
   setConnectionHost,
   setConnectionCert,
-  setConnectionMacaroon
+  setConnectionMacaroon,
+  startLndHostError,
+  startLndCertError,
+  startLndMacaroonError
 }) => (
   <div className={styles.container}>
-    <div>
+    <section className={styles.input}>
       <label htmlFor="connectionHost">Host:</label>
       <input
         type="text"
         id="connectionHost"
         placeholder="Hostname / Port of the Lnd gRPC interface"
-        className={styles.host}
+        className={`${styles.host} ${startLndHostError && styles.error}`}
         ref={input => input}
         value={connectionHost}
         onChange={event => setConnectionHost(event.target.value)}
       />
-    </div>
-    <div>
+      <p className={`${startLndHostError && styles.visible} ${styles.errorMessage}`}>
+        {startLndHostError}
+      </p>
+    </section>
+    <section className={styles.input}>
       <label htmlFor="connectionCert">TLS Certificate:</label>
       <input
         type="text"
         id="connectionCert"
         placeholder="Path to the lnd tls cert"
-        className={styles.cert}
+        className={`${styles.cert} ${startLndCertError && styles.error}`}
         ref={input => input}
         value={connectionCert}
         onChange={event => setConnectionCert(event.target.value)}
       />
-    </div>
-    <div>
+      <p className={`${startLndCertError && styles.visible} ${styles.errorMessage}`}>
+        {startLndCertError}
+      </p>
+    </section>
+    <section className={styles.input}>
       <label htmlFor="connectionMacaroon">Macaroon:</label>
       <input
         type="text"
         id="connectionMacaroon"
         placeholder="Path to the lnd macaroon file"
-        className={styles.macaroon}
+        className={`${styles.macaroon} ${startLndMacaroonError && styles.error}`}
         ref={input => input}
         value={connectionMacaroon}
         onChange={event => setConnectionMacaroon(event.target.value)}
       />
-    </div>
+      <p className={`${startLndMacaroonError && styles.visible} ${styles.errorMessage}`}>
+        {startLndMacaroonError}
+      </p>
+    </section>
   </div>
 )
 
@@ -56,7 +68,10 @@ ConnectionDetails.propTypes = {
   connectionMacaroon: PropTypes.string.isRequired,
   setConnectionHost: PropTypes.func.isRequired,
   setConnectionCert: PropTypes.func.isRequired,
-  setConnectionMacaroon: PropTypes.func.isRequired
+  setConnectionMacaroon: PropTypes.func.isRequired,
+  startLndHostError: PropTypes.string,
+  startLndCertError: PropTypes.string,
+  startLndMacaroonError: PropTypes.string
 }
 
 export default ConnectionDetails

app/components/Onboarding/ConnectionDetails.scss

@@ -3,6 +3,10 @@
 .container {
   color: $white;
 
+  .input {
+    margin-bottom: 15px;
+  }
+
   label {
     display: block;
     font-size: 12px;
@@ -14,20 +18,35 @@
   input {
     background: transparent;
     outline: none;
-    border:1px solid #404040;
+    border: 1px solid #404040;
     border-radius: 4px;
     padding: 10px;
     color: $gold;
     -webkit-text-fill-color: $white;
     font-size: 18px;
-    width: 100%;
     font-weight: 400;
-    margin-bottom: 20px;
     width: 600px;
+    transition: all 0.25s;
+
+    &.error {
+      border: 1px solid $red;
+    }
   }
 
   input::-webkit-input-placeholder {
     text-shadow: none;
     -webkit-text-fill-color: initial;
   }
+
+  .errorMessage {
+    margin-top: 10px;
+    color: $red;
+    height: 10px;
+    visibility: hidden;
+    font-size: 10px;
+
+    &.visible {
+      visibility: visible;
+    }
+  }
 }

app/components/Onboarding/Onboarding.js

@@ -72,10 +72,10 @@ const Onboarding = ({
             back={() => changeStep(0.1)}
             next={() =>
               startLnd({
-                connectionType,
-                connectionHost,
-                connectionCert,
-                connectionMacaroon
+                type: connectionType,
+                host: connectionHost,
+                cert: connectionCert,
+                macaroon: connectionMacaroon
               })
             }
           >
@@ -100,7 +100,7 @@ const Onboarding = ({
             title="Autopilot"
             description="Autopilot is an automatic network manager. Instead of manually adding people to build your network to make payments, enable autopilot to automatically connect you to the Lightning Network using 60% of your balance." // eslint-disable-line max-len
             back={() => changeStep(1)}
-            next={() => startLnd({ connectionType, alias, autopilot })}
+            next={() => startLnd({ type: connectionType, alias, autopilot })}
           >
             <Autopilot {...autopilotProps} />
           </FormContainer>

app/containers/Root.js

@@ -99,7 +99,10 @@ const mergeProps = (stateProps, dispatchProps, ownProps) => {
     connectionMacaroon: stateProps.onboarding.connectionMacaroon,
     setConnectionHost: dispatchProps.setConnectionHost,
     setConnectionCert: dispatchProps.setConnectionCert,
-    setConnectionMacaroon: dispatchProps.setConnectionMacaroon
+    setConnectionMacaroon: dispatchProps.setConnectionMacaroon,
+    startLndHostError: stateProps.onboarding.startLndHostError,
+    startLndCertError: stateProps.onboarding.startLndCertError,
+    startLndMacaroonError: stateProps.onboarding.startLndMacaroonError
   }
 
   const aliasProps = {

app/lnd/config/index.js

@@ -61,8 +61,8 @@ export default {
   lnd: () => ({
     lndPath,
     configPath: join(appRootPath, 'resources', 'lnd.conf'),
-    lightningRpc: join(appRootPath, 'resources', 'rpc.proto'),
-    lightningHost: store.get('host') || 'localhost:10009',
+    rpcProtoPath: join(appRootPath, 'resources', 'rpc.proto'),
+    host: store.get('host') || 'localhost:10009',
     cert: store.get('cert') || join(userInfo().homedir, loc),
     macaroon: store.get('macaroon') || join(userInfo().homedir, macaroonPath)
   })

app/lnd/index.js

@@ -1,28 +1,28 @@
 import config from './config'
 import lightning from './lib/lightning'
 import walletUnlocker from './lib/walletUnlocker'
-import isLndRunning from './lib/util'
+import { isLndRunning } from './lib/util'
 import subscribe from './subscribe'
 import methods from './methods'
 import walletUnlockerMethods from './walletUnlockerMethods'
 // use mainLog because lndLog is reserved for the lnd binary itself
 import { mainLog } from '../utils/log'
 
-const initLnd = () => {
-  const lndConfig = config.lnd()
-  const lnd = lightning(lndConfig.lightningRpc, lndConfig.lightningHost)
+const initLnd = async () => {
+  const lnd = await lightning()
+
   const lndSubscribe = mainWindow => subscribe(mainWindow, lnd, mainLog)
   const lndMethods = (event, msg, data) => methods(lnd, mainLog, event, msg, data)
 
-  return {
+  return Promise.resolve({
     lndSubscribe,
     lndMethods
-  }
+  })
 }
 
 const initWalletUnlocker = () => {
   const lndConfig = config.lnd()
-  const walletUnlockerObj = walletUnlocker(lndConfig.lightningRpc, lndConfig.lightningHost)
+  const walletUnlockerObj = walletUnlocker(lndConfig.rpcProtoPath, lndConfig.host)
   const walletUnlockerMethodsCallback = (event, msg, data) =>
     walletUnlockerMethods(walletUnlockerObj, mainLog, event, msg, data)
 

app/lnd/lib/lightning.js

@@ -1,6 +1,6 @@
-import fs from 'fs'
 import grpc from 'grpc'
 import config from '../config'
+import { getDeadline, validateHost, createSslCreds, createMacaroonCreds } from './util'
 
 // Default is ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384
 // https://github.com/grpc/grpc/blob/master/doc/environment_variables.md
@@ -19,22 +19,39 @@ process.env.GRPC_SSL_CIPHER_SUITES =
     'ECDHE-ECDSA-CHACHA20-POLY1305'
   ].join(':')
 
-const lightning = (rpcpath, host) => {
+/**
+ * Creates an LND grpc client lightning service.
+ * @returns {rpc.lnrpc.Lightning}
+ */
+const lightning = async () => {
   const lndConfig = config.lnd()
-  const lndCert = fs.readFileSync(lndConfig.cert)
-  const sslCreds = grpc.credentials.createSsl(lndCert)
-  const rpc = grpc.load(lndConfig.lightningRpc)
+  const { host, rpcProtoPath, cert, macaroon } = lndConfig
 
-  const metadata = new grpc.Metadata()
-  const macaroonHex = fs.readFileSync(lndConfig.macaroon).toString('hex')
-  metadata.add('macaroon', macaroonHex)
+  // Verify that the host is valid before creating a gRPC client that is connected to it.
+  return await validateHost(host).then(async () => {
+    // Load the gRPC proto file.
+    const rpc = grpc.load(rpcProtoPath)
 
-  const macaroonCreds = grpc.credentials.createFromMetadataGenerator((params, callback) =>
-    callback(null, metadata)
-  )
+    // Create ssl and macaroon credentials to use with the gRPC client.
+    const [sslCreds, macaroonCreds] = await Promise.all([
+      createSslCreds(cert),
+      createMacaroonCreds(macaroon)
+    ])
     const credentials = grpc.credentials.combineChannelCredentials(sslCreds, macaroonCreds)
 
-  return new rpc.lnrpc.Lightning(host, credentials)
+    // Create a new gRPC client instance.
+    const lnd = new rpc.lnrpc.Lightning(host, credentials)
+
+    // Call the getInfo method to ensure that we can make successful calls to the gRPC interface.
+    return new Promise((resolve, reject) => {
+      lnd.getInfo({}, { deadline: getDeadline(2) }, err => {
+        if (err) {
+          return reject(err)
+        }
+        return resolve(lnd)
+      })
+    })
+  })
 }
 
 export default lightning

app/lnd/lib/neutrino.js

@@ -20,8 +20,8 @@ class Neutrino extends EventEmitter {
     const lndConfig = config.lnd()
     mainLog.info('Starting lnd in neutrino mode')
     mainLog.debug(' > lndPath', lndConfig.lndPath)
-    mainLog.debug(' > lightningRpc:', lndConfig.lightningRpc)
-    mainLog.debug(' > lightningHost:', lndConfig.lightningHost)
+    mainLog.debug(' > rpcProtoPath:', lndConfig.rpcProtoPath)
+    mainLog.debug(' > host:', lndConfig.host)
     mainLog.debug(' > cert:', lndConfig.cert)
     mainLog.debug(' > macaroon:', lndConfig.macaroon)
 

app/lnd/lib/util.js

@@ -1,11 +1,100 @@
+import dns from 'dns'
+import fs from 'fs'
+import { promisify } from 'util'
 import { lookup } from 'ps-node'
+import grpc from 'grpc'
+import isIP from 'validator/lib/isIP'
+import isPort from 'validator/lib/isPort'
 import { mainLog } from '../../utils/log'
 
+const fsReadFile = promisify(fs.readFile)
+const dnsLookup = promisify(dns.lookup)
+
+/**
+ * Helper function to return an absolute deadline given a relative timeout in seconds.
+ * @param {number} timeoutSecs The number of seconds to wait before timing out
+ * @return {Date} A date timeoutSecs in the future
+ */
+export const getDeadline = timeoutSecs => {
+  var deadline = new Date()
+  deadline.setSeconds(deadline.getSeconds() + timeoutSecs)
+  return deadline.getTime()
+}
+
+/**
+ * Helper function to check a hostname in the format hostname:port is valid for passing to node-grpc.
+ * @param {string} host A hostname + optional port in the format [hostname]:[port?]
+ * @returns {Promise<Boolean>}
+ */
+export const validateHost = async host => {
+  var splits = host.split(':')
+  const lndHost = splits[0]
+  const lndPort = splits[1]
+
+  // If the hostname starts with a number, ensure that it is a valid IP address.
+  if (lndHost.match(/^\d/) && !isIP(lndHost)) {
+    const error = new Error(`${lndHost} is not a valid IP address or hostname`)
+    error.code = 'LND_GRPC_HOST_ERROR'
+    return Promise.reject(error)
+  }
+
+  // If the host includes a port, ensure that it is a valid.
+  if (lndPort && !isPort(lndPort)) {
+    const error = new Error(`${lndPort} is not a valid port`)
+    error.code = 'LND_GRPC_HOST_ERROR'
+    return Promise.reject(error)
+  }
+
+  // Do a DNS lookup to ensure that the host is reachable.
+  return dnsLookup(lndHost)
+    .then(() => true)
+    .catch(e => {
+      const error = new Error(`${lndHost} is not accessible: ${e.message}`)
+      error.code = 'LND_GRPC_HOST_ERROR'
+      return Promise.reject(error)
+    })
+}
+
+/**
+ * Validates and creates the ssl channel credentials from the specified file path
+ * @param {String} certPath
+ * @returns {grpc.ChanelCredentials}
+ */
+export const createSslCreds = async certPath => {
+  const lndCert = await fsReadFile(certPath).catch(e => {
+    const error = new Error(`SSL cert path could not be accessed: ${e.message}`)
+    error.code = 'LND_GRPC_CERT_ERROR'
+    throw error
+  })
+
+  return grpc.credentials.createSsl(lndCert)
+}
+
+/**
+ * Validates and creates the macaroon authorization credentials from the specified file path
+ * @param {String} macaroonPath
+ * @returns {grpc.CallCredentials}
+ */
+export const createMacaroonCreds = async macaroonPath => {
+  const macaroon = await fsReadFile(macaroonPath).catch(e => {
+    const error = new Error(`Macaroon path could not be accessed: ${e.message}`)
+    error.code = 'LND_GRPC_MACAROON_ERROR'
+    throw error
+  })
+
+  const metadata = new grpc.Metadata()
+  metadata.add('macaroon', macaroon.toString('hex'))
+
+  return grpc.credentials.createFromMetadataGenerator((params, callback) =>
+    callback(null, metadata)
+  )
+}
+
 /**
  * Check to see if an LND process is running.
  * @return {Promise} Boolean indicating wether an existing lnd process was found on the host machine.
  */
-const isLndRunning = () => {
+export const isLndRunning = () => {
   return new Promise((resolve, reject) => {
     mainLog.info('Looking for existing lnd process')
     lookup({ command: 'lnd' }, (err, results) => {
@@ -24,5 +113,3 @@ const isLndRunning = () => {
     })
   })
 }
-
-export default isLndRunning

app/lnd/lib/walletUnlocker.js

@@ -23,7 +23,7 @@ const walletUnlocker = (rpcpath, host) => {
   const lndConfig = config.lnd()
   const lndCert = fs.readFileSync(lndConfig.cert)
   const credentials = grpc.credentials.createSsl(lndCert)
-  const rpc = grpc.load(lndConfig.lightningRpc)
+  const rpc = grpc.load(lndConfig.rpcProtoPath)
 
   return new rpc.lnrpc.WalletUnlocker(host, credentials)
 }

app/package.json

@@ -14,7 +14,7 @@
   },
   "license": "MIT",
   "dependencies": {
-    "grpc": "^1.12.3",
+    "grpc": "^1.12.4",
     "ps-node": "^0.1.6",
     "react-icons": "^2.2.5"
   }

app/reducers/ipc.js

@@ -40,6 +40,7 @@ import { receiveDescribeNetwork, receiveQueryRoutes, receiveInvoiceAndQueryRoute
 
 import {
   startOnboarding,
+  startLndError,
   walletUnlockerStarted,
   receiveSeed,
   receiveSeedError,
@@ -107,6 +108,7 @@ const ipc = createIpc({
   receiveInvoiceAndQueryRoutes,
 
   startOnboarding,
+  startLndError,
   walletUnlockerStarted,
   receiveSeed,
   receiveSeedError,

app/reducers/onboarding.js

@@ -36,6 +36,7 @@ export const ONBOARDING_FINISHED = 'ONBOARDING_FINISHED'
 
 export const STARTING_LND = 'STARTING_LND'
 export const LND_STARTED = 'LND_STARTED'
+export const SET_START_LND_ERROR = 'SET_START_LND_ERROR'
 
 export const CREATING_NEW_WALLET = 'CREATING_NEW_WALLET'
 
@@ -45,6 +46,7 @@ export const SET_UNLOCK_WALLET_ERROR = 'SET_UNLOCK_WALLET_ERROR'
 
 export const SET_SIGNUP_CREATE = 'SET_SIGNUP_CREATE'
 export const SET_SIGNUP_IMPORT = 'SET_SIGNUP_IMPORT'
+
 // ------------------------------------
 // Actions
 // ------------------------------------
@@ -204,6 +206,11 @@ export const startOnboarding = () => dispatch => {
   dispatch({ type: ONBOARDING_STARTED })
 }
 
+// Listener for errors connecting to LND gRPC
+export const startLndError = (event, errors) => dispatch => {
+  dispatch({ type: SET_START_LND_ERROR, errors })
+}
+
 // Listener from after the LND walletUnlocker has started
 export const walletUnlockerStarted = () => dispatch => {
   dispatch({ type: LND_STARTED })
@@ -293,6 +300,13 @@ const ACTION_HANDLERS = {
 
   [STARTING_LND]: state => ({ ...state, startingLnd: true }),
   [LND_STARTED]: state => ({ ...state, startingLnd: false }),
+  [SET_START_LND_ERROR]: (state, { errors }) => ({
+    ...state,
+    startingLnd: false,
+    startLndHostError: errors.host,
+    startLndCertError: errors.cert,
+    startLndMacaroonError: errors.macaroon
+  }),
 
   [CREATING_NEW_WALLET]: state => ({ ...state, creatingNewWallet: true }),
 
@@ -366,7 +380,7 @@ export { onboardingSelectors }
 // Reducer
 // ------------------------------------
 const initialState = {
-  onboarded: true,
+  onboarded: false,
   step: 0.1,
   connectionType: store.get('type', ''),
   connectionHost: store.get('host', ''),
@@ -374,7 +388,11 @@ const initialState = {
   connectionMacaroon: store.get('macaroon', ''),
   alias: store.get('alias', ''),
   password: '',
+
   startingLnd: false,
+  startLndHostError: '',
+  startLndCertError: '',
+  startLndMacaroonError: '',
 
   fetchingSeed: false,
   hasSeed: false,

app/yarn.lock

@@ -171,9 +171,9 @@ glob@^7.0.5:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
-grpc@^1.12.3:
-  version "1.12.3"
-  resolved "https://registry.yarnpkg.com/grpc/-/grpc-1.12.3.tgz#b38bf05f26477d42f8285794c0b1f8b8c0b6dec3"
+grpc@^1.12.4:
+  version "1.12.4"
+  resolved "https://registry.yarnpkg.com/grpc/-/grpc-1.12.4.tgz#85a3bc26dbf61fb8555d182aec42c1ab6b303ecd"
   dependencies:
     lodash "^4.17.5"
     nan "^2.0.0"

app/zap.js

@@ -54,10 +54,10 @@ class ZapController {
       Promise.resolve(this.mode)
         .then(mode => {
           const timeUntilWeKnowTheRunMode = mainLog.timeEnd('Time until we know the run mode')
-          return setTimeout(() => {
+          return setTimeout(async () => {
             if (mode === 'external') {
               // If lnd is already running, create and subscribe to the Lightning grpc object.
-              this.startGrpc()
+              await this.startGrpc()
               this.sendMessage('successfullyCreatedWallet')
             } else {
               // Otherwise, start the onboarding process.
@@ -90,10 +90,9 @@ class ZapController {
   /**
    * Create and subscribe to the Lightning grpc object.
    */
-  startGrpc() {
+  async startGrpc() {
     mainLog.info('Starting gRPC...')
-    try {
-      const { lndSubscribe, lndMethods } = lnd.initLnd()
+    const { lndSubscribe, lndMethods } = await lnd.initLnd()
 
     // Subscribe to bi-directional streams
     lndSubscribe(this.mainWindow)
@@ -104,13 +103,6 @@ class ZapController {
     })
 
     this.sendMessage('grpcConnected')
-    } catch (error) {
-      dialog.showMessageBox({
-        type: 'error',
-        message: `Unable to connect to lnd. Please check your lnd node and try again: ${error}`
-      })
-      app.quit()
-    }
   }
 
   /**
@@ -163,9 +155,9 @@ class ZapController {
       this.startWalletUnlocker()
     })
 
-    this.neutrino.on('wallet-opened', () => {
+    this.neutrino.on('wallet-opened', async () => {
       mainLog.info('Wallet opened')
-      this.startGrpc()
+      await this.startGrpc()
       this.sendMessage('lndSyncing')
     })
 
@@ -185,30 +177,56 @@ class ZapController {
    * Add IPC event listeners...
    */
   _registerIpcListeners() {
-    ipcMain.on('startLnd', (event, options = {}) => {
+    ipcMain.on('startLnd', async (event, options = {}) => {
+      // Trim any user supplied strings.
+      const cleanOptions = Object.keys(options).reduce((previous, current) => {
+        previous[current] =
+          typeof options[current] === 'string' ? options[current].trim() : options[current]
+        return previous
+      }, {})
+
+      // Save the options.
       const store = new Store({ name: 'connection' })
-      store.store = {
-        type: options.connectionType,
-        host: options.connectionHost,
-        cert: options.connectionCert,
-        macaroon: options.connectionMacaroon,
-        alias: options.alias,
-        autopilot: options.autopilot
-      }
+      store.store = cleanOptions
       mainLog.info('Saved lnd config to:', store.path)
 
-      if (options.connectionType === 'local') {
+      // If the requested connection type is a local one then start up a new lnd instance.
+      if (cleanOptions.type === 'local') {
         mainLog.info('Starting new lnd instance')
-        mainLog.debug(' > alias:', options.alias)
-        mainLog.debug(' > autopilot:', options.autopilot)
-        this.startLnd(options.alias, options.autopilot)
-      } else {
+        mainLog.debug(' > alias:', cleanOptions.alias)
+        mainLog.debug(' > autopilot:', cleanOptions.autopilot)
+        this.startLnd(cleanOptions.alias, cleanOptions.autopilot)
+      }
+      // Otherwise attempt to connect to an lnd instance using user supplied connection details.
+      else {
         mainLog.info('Connecting to custom lnd instance')
-        mainLog.debug(' > connectionHost:', options.connectionHost)
-        mainLog.debug(' > connectionCert:', options.connectionCert)
-        mainLog.debug(' > connectionMacaroon:', options.connectionMacaroon)
-        this.startGrpc()
-        this.sendMessage('successfullyCreatedWallet')
+        mainLog.debug(' > host:', cleanOptions.host)
+        mainLog.debug(' > cert:', cleanOptions.cert)
+        mainLog.debug(' > macaroon:', cleanOptions.macaroon)
+        await this.startGrpc()
+          .then(() => this.sendMessage('successfullyCreatedWallet'))
+          .catch(e => {
+            const errors = {}
+            // There was a problem connectig to the host.
+            if (e.code === 'LND_GRPC_HOST_ERROR') {
+              errors.host = e.message
+            }
+            // There was a problem accessing loading the ssl cert.
+            if (e.code === 'LND_GRPC_CERT_ERROR') {
+              errors.cert = e.message
+            }
+            //  There was a problem accessing loading the macaroon file.
+            else if (e.code === 'LND_GRPC_MACAROON_ERROR') {
+              errors.macaroon = e.message
+            }
+            // Other error codes such as UNAVAILABLE most likely indicate that there is a problem with the host.
+            else {
+              errors.host = `Unable to connect to host: ${e.details || e.message}`
+            }
+
+            // Notify the app of errors.
+            return this.sendMessage('startLndError', errors)
+          })
       }
     })
   }

package.json

@@ -248,7 +248,8 @@
     "reselect": "^3.0.1",
     "satoshi-bitcoin": "^1.0.4",
     "source-map-support": "^0.5.6",
-    "split2": "^2.2.0"
+    "split2": "^2.2.0",
+    "validator": "^10.4.0"
   },
   "main": "webpack.config.base.js",
   "directories": {

yarn.lock

@@ -11720,6 +11720,10 @@ validate-npm-package-license@^3.0.1:
     spdx-correct "^3.0.0"
     spdx-expression-parse "^3.0.0"
 
+validator@^10.4.0:
+  version "10.4.0"
+  resolved "https://registry.yarnpkg.com/validator/-/validator-10.4.0.tgz#ee99a44afb3bb5ed350a159f056ca72a204cfc3c"
+
 value-equal@^0.2.0:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/value-equal/-/value-equal-0.2.1.tgz#c220a304361fce6994dbbedaa3c7e1a1b895871d"