From 662db2094872a7985e4762997617776e3b16696b Mon Sep 17 00:00:00 2001
From: Pascal Hartig <realpassy@fb.com>
Date: Tue, 9 Jul 2019 04:15:32 -0700
Subject: [PATCH] Disallow `var`

Summary: We're ES6 and `var`s scoping rules are weird. Let's block this.

Reviewed By: jknoxville

Differential Revision: D16131290

fbshipit-source-id: ba67d16bb8a185a4bb59a657a97b00230dbacafe
---
 .eslintrc.js                        | 1 +
 headless/index.js                   | 2 +-
 src/__tests__/server.device.js      | 4 ++--
 src/dispatcher/desktopDevice.js     | 2 +-
 src/fb-stubs/Logger.js              | 2 +-
 src/plugins/cpu/index.js            | 2 +-
 src/plugins/databases/index.js      | 2 +-
 src/server.js                       | 2 +-
 static/transforms/electron-stubs.js | 6 +++---
 9 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/.eslintrc.js b/.eslintrc.js
index 5a14dc957..c148fc7f8 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -21,6 +21,7 @@ module.exports = {
     'no-catch-shadow': 0, // only relevant for IE8 and below
     'no-bitwise': 0, // bitwise operations needed in some places
     'consistent-return': 0,
+    'no-var': 2,
     'max-len': 0, // let's take prettier take care of this
     indent: 0, // let's take prettier take care of this
     'no-console': 0, // we're setting window.console in App.js
diff --git a/headless/index.js b/headless/index.js
index 19bcdd642..d2851de74 100644
--- a/headless/index.js
+++ b/headless/index.js
@@ -146,7 +146,7 @@ async function exitActions(
   store: Store,
 ): Promise<void> {
   const {metrics, exit} = userArguments;
-  for (var exitAction of exitClosures) {
+  for (let exitAction of exitClosures) {
     try {
       const action = await exitAction(userArguments, store);
       if (action.exit) {
diff --git a/src/__tests__/server.device.js b/src/__tests__/server.device.js
index f3aded8ff..019bd4550 100644
--- a/src/__tests__/server.device.js
+++ b/src/__tests__/server.device.js
@@ -37,8 +37,8 @@ beforeAll(() => {
 });
 
 test('Device can connect successfully', done => {
-  var testFinished = false;
-  var disconnectedTooEarly = false;
+  let testFinished = false;
+  let disconnectedTooEarly = false;
   const registeredClients = [];
   server.addListener('new-client', (client: Client) => {
     // Check there is a connected device that has the same device_id as the new client
diff --git a/src/dispatcher/desktopDevice.js b/src/dispatcher/desktopDevice.js
index 0c52b4f21..8bd949255 100644
--- a/src/dispatcher/desktopDevice.js
+++ b/src/dispatcher/desktopDevice.js
@@ -12,7 +12,7 @@ import MacDevice from '../devices/MacDevice';
 import WindowsDevice from '../devices/WindowsDevice';
 
 export default (store: Store, logger: Logger) => {
-  var device;
+  let device;
   if (process.platform === 'darwin') {
     device = new MacDevice();
   } else if (process.platform === 'win32') {
diff --git a/src/fb-stubs/Logger.js b/src/fb-stubs/Logger.js
index 11d2e575b..eaf51cd1e 100644
--- a/src/fb-stubs/Logger.js
+++ b/src/fb-stubs/Logger.js
@@ -9,7 +9,7 @@ import type {TrackType, Logger} from '../fb-interfaces/Logger';
 import type {Store} from '../reducers/index';
 import ScribeLogger from './ScribeLogger';
 
-var instance: ?StubLogger = null;
+let instance: ?StubLogger = null;
 
 type Args = {
   isHeadless?: boolean,
diff --git a/src/plugins/cpu/index.js b/src/plugins/cpu/index.js
index cef4a8552..d55e77433 100644
--- a/src/plugins/cpu/index.js
+++ b/src/plugins/cpu/index.js
@@ -6,7 +6,7 @@
  */
 
 import {FlipperDevicePlugin, Device} from 'flipper';
-var adb = require('adbkit-fb');
+let adb = require('adbkit-fb');
 import TemperatureTable from './TemperatureTable.js';
 
 import {
diff --git a/src/plugins/databases/index.js b/src/plugins/databases/index.js
index 80025a345..7497e5119 100644
--- a/src/plugins/databases/index.js
+++ b/src/plugins/databases/index.js
@@ -165,7 +165,7 @@ function transformRow(
   index: number,
 ): TableBodyRow {
   const transformedColumns = {};
-  for (var i = 0; i < columns.length; i++) {
+  for (let i = 0; i < columns.length; i++) {
     transformedColumns[columns[i]] = {value: renderValue(row[i])};
   }
   return {key: String(index), columns: transformedColumns};
diff --git a/src/server.js b/src/server.js
index 2cebfeb1d..72f1517c7 100644
--- a/src/server.js
+++ b/src/server.js
@@ -334,7 +334,7 @@ class ConnectionTracker {
   logConnectionAttempt(client: ClientQuery) {
     const key = `${client.os}-${client.device}-${client.app}`;
     const time = Date.now();
-    var entry = this.connectionAttempts.get(key) || [];
+    let entry = this.connectionAttempts.get(key) || [];
     entry.push(time);
     entry = entry.filter(t => t >= time - this.timeWindowMillis);
 
diff --git a/static/transforms/electron-stubs.js b/static/transforms/electron-stubs.js
index d7d3c5bbf..2a0859013 100644
--- a/static/transforms/electron-stubs.js
+++ b/static/transforms/electron-stubs.js
@@ -5,10 +5,10 @@
  * @format
  */
 
-var babylon = require('@babel/parser');
-var fs = require('fs');
+let babylon = require('@babel/parser');
+let fs = require('fs');
 
-var electronStubs = babylon.parseExpression(
+let electronStubs = babylon.parseExpression(
   fs.readFileSync('static/electron-stubs.notjs').toString(),
 );