refactor: extract non-lnd specific util methods

app/lib/lnd/lightning.js

@@ -5,7 +5,8 @@ import { loadSync } from '@grpc/proto-loader'
 import { BrowserWindow } from 'electron'
 import StateMachine from 'javascript-state-machine'
 import LndConfig from './config'
-import { getDeadline, validateHost, createSslCreds, createMacaroonCreds, waitForFile } from './util'
+import { getDeadline, createSslCreds, createMacaroonCreds, waitForFile } from './util'
+import { validateHost } from '../utils/validateHost'
 import methods from './methods'
 import { mainLog } from '../utils/log'
 import subscribeToTransactions from './subscribe/transactions'

app/lib/lnd/util.js

@@ -1,4 +1,3 @@
-import dns from 'dns'
 import fs from 'fs'
 import axios from 'axios'
 import { promisify } from 'util'
@@ -7,14 +6,10 @@ import { platform } from 'os'
 import { app } from 'electron'
 import isDev from 'electron-is-dev'
 import grpc from 'grpc'
-import isFQDN from 'validator/lib/isFQDN'
-import isIP from 'validator/lib/isIP'
-import isPort from 'validator/lib/isPort'
 import get from 'lodash.get'
 import { mainLog } from '../utils/log'
 
 const fsReadFile = promisify(fs.readFile)
-const dnsLookup = promisify(dns.lookup)
 
 // ------------------------------------
 // Constants
@@ -107,40 +102,6 @@ export const getDeadline = 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 (!isFQDN(lndHost, { require_tld: false }) && !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

app/lib/lnd/walletUnlocker.js

@@ -4,7 +4,8 @@ import grpc from 'grpc'
 import { loadSync } from '@grpc/proto-loader'
 import StateMachine from 'javascript-state-machine'
 import LndConfig from './config'
-import { getDeadline, validateHost, createSslCreds } from './util'
+import { getDeadline, createSslCreds } from './util'
+import { validateHost } from '../utils/validateHost'
 import methods from './walletUnlockerMethods'
 import { mainLog } from '../utils/log'
 

app/lib/utils/fileExists.js

@@ -0,0 +1,7 @@
+import fs from 'fs'
+import { promisify } from 'util'
+import untildify from 'untildify'
+
+const fsReadFile = promisify(fs.readFile)
+
+export const fileExists = async path => fsReadFile(untildify(path))

app/lib/utils/validateHost.js

@@ -0,0 +1,41 @@
+import dns from 'dns'
+import { promisify } from 'util'
+import isFQDN from 'validator/lib/isFQDN'
+import isIP from 'validator/lib/isIP'
+import isPort from 'validator/lib/isPort'
+
+const dnsLookup = promisify(dns.lookup)
+
+/**
+ * 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 (!isFQDN(lndHost, { require_tld: false }) && !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)
+    })
+}

test/unit/lnd/util.spec.js

@@ -1,4 +1,4 @@
-import { validateHost } from 'lib/lnd/util'
+import { validateHost } from 'lib/utils/validateHost'
 
 jest.mock('dns')